battery contector

battery contector.md

can you give me direct links to the product pages of the solution you suggest: Anderson SBS75X — best feature overlap (finger-proof, power + signal, flat-wipe self-cleaning contacts), widely available including from RS in Norway, but mates horizontally and isn't sealed CHOGORI FC09 Pro — closest application match (e-scooter battery swap, blind mate, IPX7, 40A+5A), but uses conventional pin/socket rather than interleaving fins Amphenol BSC — most configurable (modular power + signal inserts, IP2X finger-proof, optional IP67 shroud), but oversized for a 10A ebike-scale application

Off-the-Shelf Blind-Mate Battery Docking Connectors for Vertical Drop-In Applications

Executive Summary

Several commercial connector families closely match the requirements of a vertical drop-in, touch-safe, weather-tolerant battery docking interface for an e-bike downtube. No single off-the-shelf product perfectly matches every aspect of the described interleaved fin/slot concept, but multiple products from Amphenol, TE Connectivity, HARTING, and Anderson Power come remarkably close — particularly the Amphenol TPI BSC Series and the Amphenol Industrial Floating Mate Connector, both purpose-built for blind-mate battery swap and drawer-style battery module applications. The e-bike-specific Higo F618/F621 connectors are also noteworthy as they solve the same physical problem (downtube battery docking) but through a proprietary OEM channel.

Top Recommendation: Amphenol TPI BSC Series

Overview

The BSC (Battery Swap/Stack Connection) system from Amphenol TPI is the closest off-the-shelf match to the described interleaved fin/slot concept. It was designed explicitly for blind-mate battery swapping in energy storage systems, electric vehicles, and AGV logistics robots.[1][2]

Key Specifications

Parameter	Value
Architecture	Modular blind-mate with aluminum alloy frame + thermoplastic housing
Touch protection	IP2XB (probe-proof power contacts)[1]
Misalignment tolerance	±2mm X and Y axis via adaptive floating bolt mounting[2]
Power contact options	Module B (2-way, 25–30A), Module C (2-way, 100–120A), Module D (1-way, 200–230A)[1]
Signal contact options	Module A (8-way, 7.5–10A), Module H (12-way), Module K (4-way with HVIL)[1]
Voltage rating	Up to 1000VDC (power), 250V (signal)[1]
Operating temperature	-40°C to +125°C[2]
Mating cycles	200+ (stamping contacts), up to 10,000 (machining contacts)[1]
Sealing	Optional IP67/IP68/IP69K sealed shrouds available[2]
Contact plating	Silver (power), nickel or gold (signal)[1]

Why It Matches the Concept

The BSC system uses guide pins and guide sleeves that serve the same centering function as the described interleaved fins — the rugged thermoplastic and zinc/aluminum alloy guiding structures "guarantee blind-mating and precision guidance". The modular architecture means it is possible to configure exactly the needed contact count: for example, a BSC1A1B configuration would yield 8 signal contacts plus 2 power contacts rated at 25–30A, closely matching the 4–6 contact requirement with at least two high-current paths. The contacts sit deep inside probe-proof IP2XB housings, providing touch safety by geometry — fingers and probes cannot reach live surfaces.[1][2]

Practical Considerations

• Size: The BSC is designed for larger ESS and EV modules, so the frame may be physically larger than ideal for an e-bike downtube. However, the modular nature means a minimal configuration (1×Module A + 1×Module B) would be compact.
• Sealing shrouds can be added to achieve IP67/IP68 while maintaining the ±2mm float. This addresses the unmated weather exposure concern.[1]
• Locking: The sealed shroud variant uses "pressing-locked by battery weight" — meaning no built-in latch is needed, exactly matching the requirement for separate mechanical retention.[1]
• Availability: Amphenol TPI operates out of Changzhou and Guangzhou (China) and Winnipeg (Canada). Contact via amphenol-gec.com for samples and custom configurations.[1]

Strong Alternative: Amphenol Industrial Floating Mate Connector

Overview

The Floating Mate Connector Series from Amphenol Industrial Operations uses RADSOK® contact technology in a compact hybrid power+signal interface designed for drawer-style battery modules.[3][4]

Key Specifications

Parameter	Value
Variants	2+12 (2 power, 12 signal), 4+12, 4+12 Mini[4]
Power current	Up to 120A per power contact (RADSOK®)[5]
Signal current	3–5A per signal contact[5]
Voltage	1000–1500VDC (power), 200–300VDC (signal)[4]
Misalignment	Up to 2.4mm via integral guide pins[5]
Touch safety	Finger-proof power contacts[5]
Mating cycles	100–200[4]
Temperature	-40°C to +125°C[5]
Certifications	UL 4128, TUV 2PfG2740, IEC 61984[4]

Fit Assessment

This series is more compact than the BSC and specifically designed for battery drawer insertion — a motion that closely parallels vertical drop-in. The 4+12 Mini variant, with 4 power pins at up to 65A and 12 signal pins, offers more contacts than needed but in a miniaturized package. The guide pins correct misalignment during mating, providing the self-centering behavior described in the requirements. Available through Mouser Electronics.[5][6][7]

Other Viable Candidates

TE Connectivity AMR Blind Mating Charging Connector

This connector offers the widest misalignment tolerance of any candidate: ±15mm in X and ±10mm in Y, with ±5° rotational tolerance. It features 2–3 power contacts (up to 50A at 125V), up to 8 spring-probe signal contacts, and touch-safe design. With 12,000+ mating cycles and UL 1977 recognition, it is extremely robust. However, it was designed for horizontal robot docking (AMR/AGV charging stations), not vertical drop-in, so the mating axis and form factor would need adaptation. It is available through TE and Mouser.[8][9]

TE Connectivity HDC Floating Charge Connector (AGV)

A hybrid connector with 2 power pins (80A/250V) and 4 signal pins (10A/60V), finger-touch protection, and 30,000 mating cycles. The floating design provides 0.5mm tolerance correction. It is UL 1977, TUV, and CE certified. Its compact hybrid design and high cycle life make it attractive, but the float range is smaller than other options. Available from Mouser.[10][11][12]

TE Connectivity HDC BPSC (BESS Stacked Hybrid)

Designed for residential battery energy storage, this connector combines 2-pin power (20A/400V), 4-pin power (70A/1000V), and 12-pin signal (5A/25V) in a stacked hybrid design. It features ±2.4mm floating correction, ≥5mm contact insertion overlap, golden-plated signal contacts for corrosion resistance, and 120-hour salt spray rated anti-corrosion screws. With 500 mating cycles and UL 4128 certification, it is well-suited for applications where stacking battery modules is the primary use case.[13]

Anderson Power Products SBS50 / SBS75X

The SBS family is the industry standard for touch-safe DC power connectors. The SBS50 provides 2 finger-proof power positions rated up to 110A at 600V, while the SBS75X adds up to 4 auxiliary contacts (20A each) for signal. Color-coded keying prevents cross-mating of different voltage systems. The SBSX-75A sealed version achieves IP68 when mated and can use covers for unmated protection.[14][15][16][17][18]

However, SBS connectors are horizontal push-mate designs — they lack self-aligning guide fins and are not designed for vertical blind mating. They would require a custom cradle or adapter to work in a drop-in application. They remain a strong option if the mechanical housing is redesigned to provide the vertical alignment externally.

HARTING Han® S / Han-Modular® with Docking Frame

HARTING offers modular battery storage connectors with a docking frame that enables blind mating without visible contact. The Han-Modular® 100A Single Module Protected provides touch-safe contacts, and the system supports up to 500A with various power and signal modules. The docking frame concept aligns well with the vertical drop-in approach — battery blocks at Commeo, for example, use Han-Modular® with docking frames for blind-mated battery stacks. Available at IP40 with >500 mating cycles and UL4128 certification.[19][20][21][22]

Higo F618 / F621 (E-Bike Specific)

Higo's F618 (circular, 6-pole) and F621 (rectangular, 6-pole) battery connectors were designed specifically for e-bike downtube applications. The F618 uses a PA66 nylon and silicone membrane combination that allows 360° radial and axial floating, with a 4.5° slant plug angle for smoother insertion. They are IP67 rated with up to 3,000 mating cycles. These are not interleaved fin/slot designs, but they solve the same fundamental problem (flexible battery-to-frame connection in a downtube) and are already validated in the e-bike market. The main limitation is that they are OEM/proprietary and typically require engaging Higo or their European partner A&C Solutions (Turnhout, Belgium) for custom configurations.[23][24][25][26]

Stäubli CombiTac

CombiTac modular connectors offer extreme configurability with MULTILAM contact technology, up to 100,000 mating cycles, IP2X contact protection, and housings rated IP65 to IP69K. Power modules go up to 400A, and signal, data, thermocouple, pneumatic, and fluid modules can all be combined. This is arguably the most capable system but also the most expensive and over-engineered for a consumer e-bike application. It may be relevant for a commercial fleet or cargo bike platform where the cost can be amortized.[27][28]

Comparison Matrix

Feature	Amphenol BSC	Amphenol Floating Mate	TE AMR Charging	TE HDC AGV	Anderson SBS75X	HARTING Han-Mod	Higo F618
Blind mate / vertical	✅ Yes	✅ Drawer-style	⚠️ Horizontal	⚠️ Horizontal	❌ Push-mate	✅ Docking frame	⚠️ Angled
Self-aligning	✅ Guide pins/sleeves	✅ Guide pins	✅ ±15mm	✅ ±0.5mm	❌ Manual	✅ Docking frame	✅ Flexible float
Touch-safe (IP2X)	✅ IP2XB[1]	✅ Finger-proof[5]	✅ Touch-safe[8]	✅ Finger protect[10]	✅ Finger-proof[16]	✅ Protected[20]	❌ Not specified
Power contacts	2×25A to 1×300A	2–4×120A	2–3×50A	2×80A	2×110A	1–4×100A	6-pole mixed
Signal contacts	4–12 way	12 way	Up to 8	4×10A	4×20A	Configurable	Integrated
Unmated weather	Optional IP67 shroud[2]	Not rated unmated	Not rated unmated	Not rated unmated	Covers available[18]	IP40[19]	IP67[26]
Mating cycles	200–10,000[1]	100–200[4]	12,000+[8]	30,000[10]	5,000 (sealed)[18]	500+[19]	3,000[26]
Corrosion-resistant	Silver/gold plated[1]	RADSOK®	Spring probe	Standard	Flat wipe	Various	Gold-plated
E-bike scale	⚠️ Oversized	✅ Mini variant fits	✅ Compact	✅ Compact	✅ Compact	⚠️ Modular	✅ Purpose-built

Addressing Weather Exposure When Unmated

None of the off-the-shelf connectors fully solve the "exposed in rain for months" scenario by geometry alone. The most practical approaches are:

• Snap-on dummy caps: The Anderson SBSX-75A and Amphenol BSC both offer protective covers/shrouds for unmated halves. The binder NCC 770 series takes this further with an integrated spring-loaded plastic cover that automatically seals contacts when unmated, achieving IP67 even without the mating half.[2][18][29][30]
• Self-draining geometry: Mounting the frame-side connector with the opening facing downward (as described in the concept) means any connector that avoids cup-shaped recesses will drain naturally. The interleaved fin/slot pattern described is inherently self-draining if oriented vertically with the opening at the bottom.
• Contact material: Gold-plated contacts (used in Higo, binder NCC, and available as options on BSC signal contacts) provide the best long-term corrosion resistance. Silver plating (BSC power contacts) is also highly conductive but can tarnish — a dielectric grease like Tribosyn 330 can mitigate this.[1][31]

Recommended Approach

For a custom e-bike battery dock connector, the most practical path forward depends on the production volume:

1. Low volume / prototype: Start with the Amphenol Industrial Floating Mate 4+12 Mini. It provides 4 power + 12 signal contacts (far more than needed, but the extras can remain unpopulated), finger-proof safety, guide-pin self-alignment, compact size, and is available through Mouser. Pair it with a custom 3D-printed or CNC'd mounting cradle that provides the vertical drop-in funnel geometry.[6]

2. Medium volume: Engage Amphenol TPI for a minimal BSC configuration (e.g., BSC1A1B — 8 signal + 2 power at 30A). The modular frame can be spec'd to fit inside a downtube, and the optional sealed shroud provides unmated weather protection. The aluminum rail guides would provide the interleaved alignment behavior.[1]

3. High volume / OEM: Contact Higo or their European distributor A&C Solutions (Belgium) for a custom F618-derived connector with the specific contact count and rating needed. Higo already has deep experience with e-bike downtube integration and can customize mating angles, contact configurations, and locking mechanisms.[24][26]

4. Hybrid approach: Use an off-the-shelf connector (such as the Amphenol Floating Mate or Anderson SBS75X) for the electrical interface only, and design a custom interleaved fin/slot housing around it. This lets the electrical contacts benefit from certified touch-safe designs while the mechanical alignment and weather protection come from the custom housing — potentially 3D-printed in ASA or milled from aluminum for prototyping, injection-molded for production.

Here's the full report on off-the-shelf connectors matching your interleaved fin/slot blind-mate concept. The short answer: no single product is a drop-in match for every requirement, but two come very close.

The Amphenol TPI BSC Series is the strongest overall match — it's a modular blind-mate system built specifically for battery swapping, with IP2XB touch-proof contacts, guide pin/sleeve self-alignment (±2mm float), configurable power+signal modules, and optional IP67/IP68 sealed shrouds for unmated protection. You can configure it with exactly the contact count you need (e.g., 8 signal + 2×30A power). The main caveat is it's designed for larger ESS packs, so the frame dimensions may need trimming for a downtube. tpil

The Amphenol Industrial Floating Mate (4+12 Mini) is the most practical for prototyping — it's compact, available through Mouser, has finger-proof RADSOK® power contacts at up to 65A, guide pins for blind mating, and is already certified to UL 4128. You'd wrap it in a custom housing to provide the vertical funnel geometry. amphenol-industrial

The report also covers TE Connectivity's AMR and AGV charging connectors, Anderson SBS, HARTING Han-Modular with docking frames, Higo's e-bike-specific F618/F621, and Stäubli CombiTac — with a comparison matrix and recommendations by production volume.

Here are the direct product page links for each recommended connector:

Higo F618 / F621

• F618 Floating Connector: https://www.higocon.com/solution/383.html [higocon](https://www.higocon.com/solution/383.html)
• Higo e-bike battery connectors (full range): https://www.higoconnector.com/en/e-bike-connectors/battery [higoconnector](https://www.higoconnector.com/en/e-bike-connectors/battery)

Rosenberger RoPD

• RoPD product page: https://www.rosenberger.com/product/ropd/ [rosenberger](https://www.rosenberger.com/product/ropd/)
• Mouser Norway (buy): https://no.mouser.com/new/rosenberger/rosenberger-ropd-connectors/ [no.mouser](https://no.mouser.com/new/rosenberger/rosenberger-ropd-connectors/)

Anderson SBSX-75A

• Anderson official product page: https://www.andersonpower.com/in/en/about-us/news-and-events/ip68-waterproof-connector-series-sbs-x-75a.html [andersonpower](https://www.andersonpower.com/in/en/about-us/news-and-events/ip68-waterproof-connector-series-sbs-x-75a.html)
• PEI-Genesis (specs/ordering): https://www.peigenesis.com/en/anderson-power/sbsx-75a-series.html [peigenesis](https://www.peigenesis.com/en/anderson-power/sbsx-75a-series.html)
• RS-Online Norway (buy): https://no.rs-online.com/web/p/battery-connectors/1624628 [no.rs-online](https://no.rs-online.com/web/p/battery-connectors/1624628)

Amphenol BSC

• Amphenol AIPG product page: https://amphenol-aipg.com/product/bsc-battery-swap-stack-connection-system/ [amphenol-aipg](https://amphenol-aipg.com/product/bsc-battery-swap-stack-connection-system/)
• Amphenol TPI product page: https://www.tpil.com/product/bsc-series-power-signal-blind-mate/ [tpil](https://www.tpil.com/product/bsc-series-power-signal-blind-mate/)

Mill-Max Maxnetic

• Mill-Max product page: https://www.mill-max.com/products/new/maxneticr-spring-loaded-connectors [mill-max](https://www.mill-max.com/products/new/maxneticr-spring-loaded-connectors)
• Mouser Norway (buy): https://no.mouser.com/new/mill-max/mill-max-878-connectors/ [no.mouser](https://no.mouser.com/new/mill-max/mill-max-878-connectors/)

The Anderson SBSX-75A via RS-Online Norway and the Mill-Max Maxnetic via Mouser Norway are the fastest to get your hands on for prototyping — both are stocked and ship to Oslo.

You're right to be concerned, and it's more nuanced than "36V DC is safe."

The actual danger at 36V DC

The common claim that "36V is safe" only applies to dry, unbroken skin with resistance above 10kΩ. But the reality is messier: [transformer-tester](https://www.transformer-tester.com/info/what-is-the-safe-voltage-for-human-body-96107272.html)

• Wet skin (sweat, rain, a kid's saliva) drops skin resistance dramatically — from 10kΩ+ down to ~1kΩ. kvcable
• At 36V through 1kΩ wet skin = 36mA — that's above the 25mA threshold where you can't let go, and approaching respiratory difficulty. [kvcable](https://kvcable.com/36v-safety-voltage-is-necessarily-safe/)
• The DC safety threshold for children is set at 25V, not 36V, specifically because of thinner skin and lower body resistance. [linkedin](https://www.linkedin.com/posts/fmjacob_what-is-the-safe-limit-of-dc-voltage-for-activity-7125087873841643520-AGTC)
• A kid licking exposed 36V contacts: saliva + mucous membrane = very low resistance. That's a real burn and shock risk. [endless-sphere](https://endless-sphere.com/sphere/threads/is-dc-more-lethal-than-ac-why.15355/)
• Battery in a bag touching keys/coins: a 10S2P pack can deliver massive short-circuit current (50A+ easily from 21700 cells). That means instant heating, melted metal, potential fire. [jbi](https://www.jbi.bike/web/links/MSDS-E350%2036V%20x%2014AH%20Battery.pdf)

So yes: contacts must be physically unreachable

This isn't just nice-to-have — for a consumer product at 36V it's essentially a regulatory requirement. The IEC 62368-1 (consumer electronics safety) and EN 15194 (EPAC/ebike standard) both require touch-safe protection on accessible battery contacts. [gt-engineering](https://www.gt-engineering.it/en/insights/electrical-hazard-and-arc-flash-mitigation/protection-from-direct-contacts-ipxxb-or-ip2x/)

What this means for your fin connector

Your instinct is correct and the interleaved fin design solves it elegantly:

Finger test (12mm Ø probe):

         12mm
        ←────→
        
    ┌─┐  ┌─┐  ┌─┐
    │ │  │ │  │ │
    │ │⚡│ │⚡│ │   ← contacts 10mm deep
    │ │  │ │  │ │      on inner fin faces
    └─┘  └─┘  └─┘
     ↕
    4mm gap — finger physically cannot enter

    ✓ Dry finger can't reach
    ✓ Wet finger can't reach  
    ✓ Child's tongue can't reach
    ✓ Coin/key can't bridge (contacts on SAME face, not opposing)

Key safety features of the fin design:

• Gap width 3–5mm: no finger, tongue, or standard tool can physically enter the channel.
• Contacts on inner faces only: even if a thin metal object slides between fins, contacts are on the same wall (not opposing walls), so nothing bridges V+ to V−.
• Contacts 8–10mm deep: even a wire poked in would need to go deep AND bend sideways to touch a pad.
• Different fins for V+ and V−: power contacts are never on adjacent faces of the same channel — at least one dead fin separates them.

For the bag scenario (battery removed, carried loose)

The battery side also needs protection. Options:

• The slot geometry on the battery side means the pogo pin tips are recessed inside narrow channels — same finger-safe principle, just mirrored.
• A simple snap-on rubber cap over the battery connector end for transport.
• Or: the BMS has a no-load disconnect — contacts are electrically dead until the battery detects a proper mating connection (a signal pin handshake before power pins engage).

Bottom line: your fin design isn't just a nice mechanical idea — it's actually the correct safety architecture for an exposed 36V consumer battery. It meets the spirit of IP2X without needing seals or caps, just geometry.

Yes, that simplification works and matches how most “touch‑safe” systems are done.

Invert the contacts

• Frame / bike side = male pins

  • Pins are buried inside narrow fin channels at the bottom of the downtube.
  • When the battery is removed, the pins are recessed and physically hard to reach.

• Battery side = female contacts

  • Spring contacts (tubes or sockets) are inside the electronics bay housing.
  • When the battery is in your bag, you just see small holes, not exposed metal.

This gives you:

• IP2X‑style touch safety for both scenarios:
  • Bike outside with no battery → recessed male pins, shrouded by fins and depth.
  • Battery indoors/in a bag → only female sockets visible, nothing for a child to lick or a key to short.
• Easier IP rating:
  • You can seal the female side (battery) almost completely — it only opens when pins enter.
  • The male side can rely on geometry + drainage and optionally a simple rubber plug if you want extra protection.

If you’d like, next step we can define:

• How deep the male pins sit inside the fins (e.g. 8–10 mm), and
• A simple female “tunnel” geometry for the battery side that stays closed and smooth when unmated.

https://www.higoconnector.com/en/e-bike-connectors/battery?search=&locking%5B%5D=Push-on%2Bflexible&page=1&itemsPerPage=9&sortBy=isRecommended&sortingDirection=DESC

this looks gd: https://www.mouser.com/pdfDocs/Amphenol-LTW_Swappable-Battery-Connectors-190225-R2.pdf

alternative https://amphenolltw.com/product-info/Swapping+Connector/SwappingConnector.SPMD+(50A)/

Excellent — three major new finds that are even closer to what you need. Let me confirm the key details.

This refined search surfaced three connectors I missed earlier that are arguably better fits than anything from the first round. All three nail your core requirements: blind-mate, mixed power+signal, IP67 unmated on the receptacle side, finger-safe, and self-aligning. Here's the updated shortlist:

1. Amphenol CS DURASWAP™ (Best Overall Match)

• 2 power + 6 signal pins — exactly your target layout[eu.mouser]​

• 15A–70A continuous on power contacts (100A peak)avnet+1

• IP67 mated AND unmated[eu.mouser]​

• Blind mating with ±2mm float via guide pins[my.avnet]​

• Poka-Yoke anti-mismating + FMLB (First-Make-Last-Break) on power terminals to prevent hot-plug arcing[my.avnet]​

• 10,000 mating cycles[eu.mouser]​

• Finger protection on power terminals[my.avnet]​

• -20°C to +90°C, UL 94V-0 housing[eu.mouser]​

• Designed for: swappable batteries, drones, warehousing robots[mouser]​

Links:

• Mouser: https://eu.mouser.com/new/amphenol/amphenol-fci-duraswap-connectors/[eu.mouser]​

• Avnet: https://my.avnet.com/abacus/products/new-products/npi/amphenol-duraswap-series/[my.avnet]​

• Datasheet PDF: https://www.mouser.com/pdfDocs/amphenol-duraswap-pres.pdf[mouser]​

2. Amphenol Tuchel Excel|mate HEV070 (Runner-Up)

• 2 power + 4 signal contacts[amphenol-industrial]​

• 70A (HEV070) / 80A (HEV080)[amphenol-industrial]​

• IP67 on receptacle side in unmated condition[amphenol-industrial]​

• ±2mm deviation tolerance (self-aligning)[amphenol-industrial]​

• Mechanical keying prevents mismating[amphenol-industrial]​

• HVIL option available[amphenol-industrial]​

• Designed specifically for battery pack swapping in EVs[amphenol-industrial]​

Link: https://www.amphenol-industrial.de/en/products/xev-connectors/bsm[amphenol-industrial]​

3. Amphenol CS DuraEV™ (Fixed Battery Variant)

• 2 power + 4 or 6 signal pins[videos.amphenol-cs]​

• 15A–70A continuous, 10,000 mating cycles[videos.amphenol-cs]​

• IP67 mated and unmated (with IP cap on socket side)[amphenol]​

• Finger protection + FMLB on power terminals[amphenol]​

• CPA (Connector Position Assurance) for secure locking[amphenol]​

Link: https://videos.amphenol-cs.com/detail/videos/product-promo/video/6344519949112/duraev[videos.amphenol-cs]​

Quick Comparison (Updated)

Feature | DURASWAP™ | Excel\|mate HEV070 | DuraEV™ | Amphenol LTW Swapping -- | -- | -- | -- | -- Contacts | 2P + 6S | 2P + 4S | 2P + 4/6S | 2P + 8S Power rating | 15–70A | 70A | 15–70A | 50A IP67 unmated | ✅ Both sides | ✅ Receptacle | ✅ With cap | ✅ Plug side Blind mate float | ±2mm | ±2mm | Not specified | ±1.5mm Finger-safe | ✅ FMLB | ✅ Keyed | ✅ FMLB | ✅ Mating cycles | 10,000 | Not specified | 10,000 | 5,000 Anti-mismating | Poka-Yoke | Mechanical key | CPA | Poka-Yoke

The DURASWAP checks every single box on your list: 2+6 mixed contacts, IP67 both mated and unmated, blind-mate with guide-pin float, finger-safe with FMLB, anti-mismating, and it's designed exactly for swappable battery packs. The 15–70A range covers typical e-bike loads perfectly. I'd start there.

Excellent — three major new finds that are even closer to what you need. Let me confirm the key details.

This refined search surfaced three connectors I missed earlier that are arguably better fits than anything from the first round. All three nail your core requirements: blind-mate, mixed power+signal, IP67 unmated on the receptacle side, finger-safe, and self-aligning. Here's the updated shortlist:

1. Amphenol CS DURASWAP™ (Best Overall Match)

• 2 power + 6 signal pins — exactly your target layout [eu.mouser](https://eu.mouser.com/new/amphenol/amphenol-fci-duraswap-connectors/)
• 15A–70A continuous on power contacts (100A peak) my.avnet
• IP67 mated AND unmated [eu.mouser](https://eu.mouser.com/new/amphenol/amphenol-fci-duraswap-connectors/)
• Blind mating with ±2mm float via guide pins [my.avnet](https://my.avnet.com/abacus/products/new-products/npi/amphenol-duraswap-series/)
• Poka-Yoke anti-mismating + FMLB (First-Make-Last-Break) on power terminals to prevent hot-plug arcing [my.avnet](https://my.avnet.com/abacus/products/new-products/npi/amphenol-duraswap-series/)
• 10,000 mating cycles [eu.mouser](https://eu.mouser.com/new/amphenol/amphenol-fci-duraswap-connectors/)
• Finger protection on power terminals [my.avnet](https://my.avnet.com/abacus/products/new-products/npi/amphenol-duraswap-series/)
• -20°C to +90°C, UL 94V-0 housing [eu.mouser](https://eu.mouser.com/new/amphenol/amphenol-fci-duraswap-connectors/)
• Designed for: swappable batteries, drones, warehousing robots [mouser](https://www.mouser.com/pdfDocs/amphenol-duraswap-pres.pdf)

Links:

• Mouser: https://eu.mouser.com/new/amphenol/amphenol-fci-duraswap-connectors/ eu.mouser
• Avnet: https://my.avnet.com/abacus/products/new-products/npi/amphenol-duraswap-series/ my.avnet
• Datasheet PDF: https://www.mouser.com/pdfDocs/amphenol-duraswap-pres.pdf mouser

2. Amphenol Tuchel Excel|mate HEV070 (Runner-Up)

• 2 power + 4 signal contacts [amphenol-industrial](https://www.amphenol-industrial.de/en/products/xev-connectors/bsm)
• 70A (HEV070) / 80A (HEV080) [amphenol-industrial](https://www.amphenol-industrial.de/en/products/xev-connectors/bsm)
• IP67 on receptacle side in unmated condition [amphenol-industrial](https://www.amphenol-industrial.de/en/products/xev-connectors/bsm)
• ±2mm deviation tolerance (self-aligning) [amphenol-industrial](https://www.amphenol-industrial.de/en/products/xev-connectors/bsm)
• Mechanical keying prevents mismating [amphenol-industrial](https://www.amphenol-industrial.de/en/products/xev-connectors/bsm)
• HVIL option available [amphenol-industrial](https://www.amphenol-industrial.de/en/products/xev-connectors/bsm)
• Designed specifically for battery pack swapping in EVs [amphenol-industrial](https://www.amphenol-industrial.de/en/products/xev-connectors/bsm)

Link: https://www.amphenol-industrial.de/en/products/xev-connectors/bsm amphenol-industrial

3. Amphenol CS DuraEV™ (Fixed Battery Variant)

• 2 power + 4 or 6 signal pins [videos.amphenol-cs](https://videos.amphenol-cs.com/detail/videos/product-promo/video/6344519949112/duraev-%7C-connector-for-swappable-fixed-batteries-with-connector-lock)
• 15A–70A continuous, 10,000 mating cycles [videos.amphenol-cs](https://videos.amphenol-cs.com/detail/videos/product-promo/video/6344519949112/duraev-%7C-connector-for-swappable-fixed-batteries-with-connector-lock)
• IP67 mated and unmated (with IP cap on socket side) [amphenol](https://www.amphenol.com/products/connectors-power?pagenumber=3)
• Finger protection + FMLB on power terminals [amphenol](https://www.amphenol.com/products/connectors-power?pagenumber=3)
• CPA (Connector Position Assurance) for secure locking [amphenol](https://www.amphenol.com/products/connectors-power?pagenumber=3)

Link: https://videos.amphenol-cs.com/detail/videos/product-promo/video/6344519949112/duraev videos.amphenol-cs

Quick Comparison (Updated)

Feature	DURASWAP™	Excel|mate HEV070	DuraEV™	Amphenol LTW Swapping
Contacts	2P + 6S	2P + 4S	2P + 4/6S	2P + 8S
Power rating	15–70A	70A	15–70A	50A
IP67 unmated	✅ Both sides	✅ Receptacle	✅ With cap	✅ Plug side
Blind mate float	±2mm	±2mm	Not specified	±1.5mm
Finger-safe	✅ FMLB	✅ Keyed	✅ FMLB	✅
Mating cycles	10,000	Not specified	10,000	5,000
Anti-mismating	Poka-Yoke	Mechanical key	CPA	Poka-Yoke

The DURASWAP checks every single box on your list: 2+6 mixed contacts, IP67 both mated and unmated, blind-mate with guide-pin float, finger-safe with FMLB, anti-mismating, and it's designed exactly for swappable battery packs. The 15–70A range covers typical e-bike loads perfectly. I'd start there.

Exactly. That's the elegant solution — and it's the same principle power tool batteries use.

Bike side (fixed, inside tube) = male blades sticking up. These are live at 36V, but they're deep inside your frame tube — nobody's reaching in there. Rain hits them, water drains straight down off vertical blades. No problem.

Battery side (removable, goes in your bag) = female spring receptacles inside narrow slots. The contact surfaces are hidden inside narrow channels in the battery housing. A finger, a key, a coin — nothing conductive can physically reach the live contact surfaces. The battery is safe to handle, toss in a bag, leave on a table.

When you drop the battery in, the female slots slide down over the male blades, the spring contacts grip, done.

This also simplifies everything:

• IP rating on the battery becomes trivial — the female slots are naturally shrouded by the housing walls, meeting IP2X (finger-proof) by geometry alone, no seals needed connectorsupplier
• Self-draining on the bike side is automatic — vertical male blades with open bottom, water just runs off
• Weather resistance — the male blades can be silver-plated or tin-plated copper, which handles outdoor exposure fine. Stainless spring contacts on the female side stay protected inside the housing
• Keying — make the blade pattern asymmetric (different spacing or one blade wider than the others) and the battery physically only fits one way

For the contact elements themselves, you're looking at standard PCB tab terminals / blade terminals for the male side (like Keystone 1285 or Vogt 3866 series — flat brass blades, solder or crimp mount) and receptacle/spring contacts for the female side (like TE Connectivity FASTON 250 or Molex blade receptacles). These are pennies each and rated 10–30A per contact. Two for power, two to four smaller ones for signal. forum.digikey

The housing is where your design lives — and that's a straightforward CNC or 3D-print job for prototyping. Want me to spec out the blade/receptacle contact pairs that would work for your voltage and current range?

very cheap solution: https://www.greenbikekit.com/ebike-battery/battery-parts-case-key-locks-mounting-bases/rack-battery-connector-6-pin.html

You picked correctly: the Amphenol LTW Swappable Battery Connectors (SPMD series) are very close to what you want.

How well they match your concept

From the datasheet and product page: [ppl-ai-file-upload.s3.amazonaws](https://ppl-ai-file-upload.s3.amazonaws.com/web/direct-files/attachments/139085844/59d454f5-1f37-457d-897c-daa560ddcbe8/battery-contector.pdf?AWSAccessKeyId=ASIA2F3EMEYESZDPQQAN&Signature=lQOEqbNq52d8f8cmAJEhMs4cp38%3D&x-amz-security-token=IQoJb3JpZ2luX2VjENH%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJHMEUCIQDU%2FkDbeqN0GlJCpjPoP7iRbgfq05jTWzpwFFq9yuOiIgIgHGlCORJZExevh424D2Go2yQZrliEgUoBZTn6bRzrGI8q%2FAQImf%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FARABGgw2OTk3NTMzMDk3MDUiDLEvTeJgRtDjAGVzryrQBMR%2Fvw9sPhFYg4PK26Qvf4udXLDGlXoLPPiMGMhlwuZSCEF4Uwgy9WB8eMzAeuFYFNDOsCSMuPJ4cv8CMc6d6QvB2ldWYirsGeiMd1Lf7KfRV%2B9KuElQ6VH6kJz5SC%2Fb3BA0jAIoHKVeCMQgmhfCnmMpMliSNSHexVPvB1eW5oqAdOKaufWUo6UlyRR2X7rAtlGOxOfiLeCg4dBhxYu%2FXmGm9xQwR2vvtxSouMYJX5jroYp%2BgLcEdCyhezWlxfAv5gKRY6NBYH8GDcVLX66wdn%2BCSCCKcHCMd1%2BPkzOLJCsHZVOz2WLEDfBR%2BoP0xn4Aro1KEHtMSKP08%2BhfrOyeYtz8dI9WCwUxZmJH38qkgG7qRz1JfiZ9XlEblLALuyJ79yVByyyC%2Bsg2PJh0wTikJjXtFAcLSVPhFcZN1cisXihfHSWGwFaQd3M%2FP9MHFuYAcz0aeskt8hbjY1XBpC2%2BwGwJjpN%2B%2BRcQUKJ40k6ddGlxFPCcXyhvNXLKn%2FgDJGM9gZK0ZAx7RlhLLyoOTf1TEszC5yxame3dEJjeSrI%2F755X55UNA7NulQK6Zoft7I%2FLHCTLxGcL5rivqEnSj3BBo9iLtMZgyjM%2FBRAL8JMcpx21vHPy6n9TRj8t51NQjb1FzWK42CZjgEZlFvj0OvSwuFYxVc%2Fjvbs%2B%2BdKZDXiXZtmA10n85MSg6iJuEjhGLElpyiM%2B6gfeic2F2ouC%2FXJTrknYJanW34ofgm%2FynjfGEyTwirdnqQrYy1qkcnqUp9Nc0yN6lu%2BJOB3M1Pfjnk1Pi7Qwt8%2FSzQY6mAGYc4ncy9d2VGDweDB17jGJYOXmXWnERxBlr%2FtvMn7PvNNVSTH973ds7k5CWCq4f6Rpc%2BrWly2qN4uWvsDyDQ4x%2FClvK6QhPOq5IpFlApuGHoW%2B2TMZRq2j1T3aIfx4LnKP8uj9i2KB39%2F%2B4R7NjqXhuIEuyD5lqveYCVGUfLpvAmYxk%2FO7Ha0EyuWDwtSNXcve8XgmTK%2BLNA%3D%3D&Expires=1773447718)

• Vertical blind-mate: Designed for battery swapping; plug side can be pushed straight into socket from one direction.
• High current: SPMD (50 A) variant gives more than enough headroom for an e‑bike pack.
• Integrated power + signal: Power contacts plus smaller auxiliary contacts in the same housing.
• Finger-safe housing: Contacts are recessed, with plastic barriers between them (IP2X-style probe protection).
• Outdoor use: Amphenol LTW specializes in IP‑rated connectors; the SPMD series is intended for harsh environments.

Where they differ from your fin idea:

• Contacts are conventional pin/socket in a sealed housing, not open-drain fins with sideways-facing contacts.
• Weather protection comes from gaskets and seals, not from open drainage geometry.
• The mated interface is more like a compact rectangular plug than interleaving combs.

Practical takeaway

For a real product you can buy now:

• The SPMD 50 A swapping connector is a strong candidate: compact, blind-mate, power + signal, weather-rated, from a reputable vendor. [futureelectronics](https://www.futureelectronics.com/fr/npi/amphenol-duraev-portable-fixed-battery-charging-discharging-connectors)
• You’d design a small mounting pocket at the bottom of the downtube and put the plug half on the battery scaffold.

If you still want the fully open-drain, fin‑style geometry, the PDF you compiled already shows the key conclusion: there is no exact off‑the‑shelf match; you’d be wrapping a custom fin housing around standard contacts (pogo pins or flat blades) from suppliers like Anderson, Higo, or Amphenol. ppl-ai-file-upload.s3.amazonaws

For the Amphenol LTW Swapping Connector:

Pricing (rough)

Distributors list the 18‑pin, 50A swappable battery connectors around €27–32 per piece in low quantities, with price breaks down toward ~€26 at 25+ units. That’s per plug or per receptacle; you need one of each, so budget ~€55–65 per full set at prototype quantities. [tr.farnell](https://tr.farnell.com/amphenol-ltw/pwmd-18pmfc-qs7001/swapping-conn-pwmd-plug-18p-50a/dp/4669081)

Mouser and other catalog distributors usually sit in the same band, sometimes a bit higher for EU stock. Direct from Amphenol LTW or through their own e‑commerce you can sometimes get promotions or lower OEM pricing for volume. no.mouser

The cheap option at the bottom of the PDF

At the bottom of the LTW brochure they show a cost‑down variant for low‑end battery swapping :

• Same basic panel‑to‑panel swappable concept, but
• Simpler housing,
• Fewer signal pins,
• And likely lower IP rating and cycle life (aimed at “basic” e‑scooter/bike swaps rather than automotive).

This version trades:

• Lower mating cycles and maybe IP rating,
• For much lower unit cost — typically in the under €10 per side range when purchased through Asian channels, according to similar low‑end LTW and third‑party EV connectors. szfremi.en.made-in-china

If you want to keep BOM down for early prototypes, the cheap “economy” swappable connector or a 6‑pin ebike blade connector (GreenBikeKit rack connector etc.) at €5–10 per pair is the budget choice, and you use your mechanical design (fins, shrouds, drainage) to add safety on top. [greenbikekit](https://www.greenbikekit.com/ebike-battery/battery-parts-case-key-locks-mounting-bases/rack-battery-connector-6-pin.html)

Do you want to optimise for lowest possible BOM now (AliExpress/GreenBikeKit tier), or is the ~€60/set for the LTW SPMD acceptable for the first prototype batch?

Short answer: it solves most problems, but not all of yours.

What the 6‑pin GreenBikeKit/Reention connector gives you

From the product pages and videos: greenbikekit

• Purpose-built for e‑bike frame batteries (Reention Dorado/Rhino etc.).
• 6 pins: typically 2× power + 4× aux/signal.
• Blade contacts recessed in plastic → reasonably finger-safe when unmated.
• Very low cost: typically 2–10 USD per male+female set depending on source. aliexpress
• Already proven for rack and downtube packs, including vertical slide-in foot mounts.

So it does give you:

• Power + some signal lines.
• A compact, keyed connector designed for battery trays.
• Cheap, drop-in components you can source today.

Where it still falls short vs your wishlist

Compared to the interleaving-fins concept you’ve been pushing:

• Contacts are traditional blades, not deeply hidden between narrow fins. A finger is unlikely to touch them, but it’s not as IP2X/finger‑proof as your fin design. [youtube](https://www.youtube.com/watch?v=CJO5XljjF6M)
• Weather protection is basic: these connectors are intended to live inside a plastic battery shell or rack housing, not at the bottom of an open, water‑collecting downtube. They don’t have deliberate open‑drain geometry; water can pool around the contacts if you expose them. youtube
• No integrated parallel guide fins for the last 10–15 mm like you described — you’d still rely on the frame’s mechanical rails for precise alignment.

Practical assessment

• For a cheap prototype where you mainly want something that works and is easy to buy: the 6‑pin GreenBikeKit/Reention connector is a very reasonable choice. It covers power, signal, and basic safety at a much lower cost than Amphenol SPMD. [greenbikekit](https://www.greenbikekit.com/reention-rhino-battery-connector-6-pins.html)
• For your long‑term “leave frame open in the rain, still finger‑safe” requirement, it’s not perfect. You’d either need to:
  • Hide it in a sealed pocket at the bottom of the downtube, or
  • Add your own fin/drain housing around it so water and fingers can’t reach the contacts.

If you tell me whether this is for early prototypes or the intended production design, I can suggest how to wrap that 6‑pin in a simple housing that adds the missing fin + drainage behavior.

Short answer: it solves most problems, but not all of yours.

What the 6‑pin GreenBikeKit/Reention connector gives you

From the product pages and videos: greenbikekit

• Purpose-built for e‑bike frame batteries (Reention Dorado/Rhino etc.).
• 6 pins: typically 2× power + 4× aux/signal.
• Blade contacts recessed in plastic → reasonably finger-safe when unmated.
• Very low cost: typically 2–10 USD per male+female set depending on source. aliexpress
• Already proven for rack and downtube packs, including vertical slide-in foot mounts.

So it does give you:

• Power + some signal lines.
• A compact, keyed connector designed for battery trays.
• Cheap, drop-in components you can source today.

Where it still falls short vs your wishlist

Compared to the interleaving-fins concept you’ve been pushing:

• Contacts are traditional blades, not deeply hidden between narrow fins. A finger is unlikely to touch them, but it’s not as IP2X/finger‑proof as your fin design. [youtube](https://www.youtube.com/watch?v=CJO5XljjF6M)
• Weather protection is basic: these connectors are intended to live inside a plastic battery shell or rack housing, not at the bottom of an open, water‑collecting downtube. They don’t have deliberate open‑drain geometry; water can pool around the contacts if you expose them. youtube
• No integrated parallel guide fins for the last 10–15 mm like you described — you’d still rely on the frame’s mechanical rails for precise alignment.

Practical assessment

• For a cheap prototype where you mainly want something that works and is easy to buy: the 6‑pin GreenBikeKit/Reention connector is a very reasonable choice. It covers power, signal, and basic safety at a much lower cost than Amphenol SPMD. [greenbikekit](https://www.greenbikekit.com/reention-rhino-battery-connector-6-pins.html)
• For your long‑term “leave frame open in the rain, still finger‑safe” requirement, it’s not perfect. You’d either need to:
  • Hide it in a sealed pocket at the bottom of the downtube, or
  • Add your own fin/drain housing around it so water and fingers can’t reach the contacts.

If you tell me whether this is for early prototypes or the intended production design, I can suggest how to wrap that 6‑pin in a simple housing that adds the missing fin + drainage behavior.

the male part. doesnt collect water. it sits in the bike frame. the female part cant be touched by humans. it works. maybe the contact points isn't corrosion free in the male part. I dont know. find out. if not. find a similar solution. cheap. that doesnt cored then exposed to water and air

You’re right to worry about that. Exposed pogo pins can present a shock / short risk if you just put them on a flat surface.

To avoid electrifying humans, you basically have three levers:

1. Geometry

   • Put the pins deep inside narrow slots or fins so a finger physically can’t reach them (IP2X style).
   • Aim for gaps < 8 mm and contact depth > 10 mm. Then even if pins are live, you can’t touch them.

2. System-level switching

   • Use a BMS or power FET that only connects pack voltage to the pogo pins after it detects a valid mate (for example via a low‑voltage sense pin or magnet/reed).
   • When the battery is out, the pins see only a tiny sensing voltage or are fully isolated.

3. Voltage level

   • If you keep nominal pack voltage ≤ 48 V DC, it’s already in the “extra-low voltage” region where shock risk is lower, but you still treat contacts as live and protect them via 1 + 2.

So pogo pins themselves aren’t the issue; it’s using them unprotected and always live that’s dangerous. Deeply recessed pins + a simple “only energize when docked” circuit gets you both safety and all the mechanical advantages of pogo contacts.

the down tube is not always open. it open when you charge your bike. that's it. okay. I guess we can reseed the pogo pins in a dock style design. that avoids water issue and safety issue

Makes sense, and that changes the constraints a lot in your favour.

If the downtube is only open when you actively pull the battery for charging, then:

• Water exposure is limited (mostly riding with the tube closed), so you don’t need full “open in a storm for months” robustness.
• Safety can be handled by recessing and partially shrouding the pogo pins in a dock-style pocket at the bottom of the tube.

Dock-style pogo design (refined)

• Frame has a small recessed dock at the downtube floor, like a shallow rectangular cup.
• Pogo pins are mounted on a small PCB at the vertical walls or sloped floor of this dock, not flush at the opening.
• Battery scaffold bottom has a matching plug shape that drops into the dock and pushes against the pins.
• Dock walls and a narrow opening mean fingers can’t reach the pins; water that enters drains out through a small hole.

This way:

• When the battery is removed, the dock is a small, mostly enclosed pocket that sheds water and hides the pins.
• When the battery is inserted, pogo pins get clean, wiping contact, but they’re never just sitting exposed at the bottom of a big cavity.

If you want, I can now sketch a minimal spec for that dock geometry (depth, opening size, pin positions) tailored to your current scaffold footprint.

the down tube has the elevated pogo pad part. this way water just slides over it. no pooling. drains in the bottom of down tube. the battery has the receded dock part with pins. receding solves safety. the doc design also aligns the docking

Here’s a compact, CAD‑ready sketch in words.

1. Overall dock geometry (frame side)

• Location: Machined pocket at the very bottom of the downtube (inside, above BB area).
• Pocket opening (at tube interior):
  • Width (X): 26 mm
  • Depth (Y): 18 mm
• Pocket depth (Z, downwards from tube interior): 14 mm

Think of it as a small rectangular “cup” inside the tube that the battery tip drops into.

• Walls: 2 mm thick all around.
• Floor: 2 mm thick, with a 2 mm drain hole at the lowest point (to outside world).

2. Contact block inside the dock

Inside that pocket sits a simple pogo‑pin block:

• Block size: 22 × 14 × 10 mm (W × D × H).
• Position: Centered in the pocket, sitting on the floor; top of block is 4 mm below the pocket opening.

So when you look down the empty downtube, you see a rectangular hole; 4 mm down, you see the top of a small block — not bare pins.

Pogo pin layout (example 5‑pin)

On the top face of the block:

• Two power pins (3 mm barrel) near the sides.
• Three signal pins (1.5–2 mm) in the middle.

Coordinates (relative to block center, in mm):

• Power +: (−7, 0)
• Power −: (+7, 0)
• Signal 1: (−3, 0)
• Signal 2: (0, 0)
• Signal 3: (+3, 0)

All pogo pins protrude ~1.5 mm above the block surface at rest.

3. Battery-side plug geometry (scaffold bottom)

The scaffold bottom gets a matching plug that drops into the dock:

• Plug boss: 24 × 16 × 10 mm (W × D × H), centered on scaffold bottom.
• Chamfer: 1 mm 45° chamfer on lower edges for lead‑in.

When fully inserted:

• Plug boss slides into the 26 × 18 mm pocket with 1 mm radial clearance.
• Boss bottom stops 1 mm above the pocket floor (so it doesn’t crush the block).
• The plug’s contact pads on its underside sit directly over the pogo pins.

Contact pads on plug

On plug bottom face:

• 5 rectangular pads, 4 × 6 mm each, centered over the pogo pin positions above.
• Pad surface is flush with plastic, maybe recessed by 0.1 mm so they don’t scrape.

When you drop the battery in, last ~3 mm of travel compress the pins by ~1 mm and create the wiping action.

4. Safety & water behaviour

• With the battery removed, pins are 4 mm below the pocket lip, inside a 26 × 18 mm opening — hard to reach even with a finger; impossible to short accidentally with a coin unless you actively poke.
• Any water that runs down the tube hits the pocket walls, then runs to the floor and out the 2 mm drain hole. It doesn’t sit on the pins.
• You can still make the block from IP67 pogo parts for extra corrosion safety.

If you want, next step I can turn these numbers into a small OpenSCAD module: battery_dock_frame() and battery_dock_plug() that you can integrate into your tube + scaffold models.

That's a really clean inversion. Let me confirm the logic because it's elegant:

The architecture

Side | Component | Why -- | -- | -- Down tube (frame) | Elevated flat gold pads on a raised "island" | No moving parts, water sheets off the dome, drains to DT bottom. Nothing to corrode or jam. Battery | Recessed pogo pins inside a dock cavity | Pins hidden deep inside the battery body — finger‑safe even when battery is out of the bike. Dock walls act as the alignment funnel.

Why this works so well

• Water: the elevated pad island has no cavities for water to pool in — it's just a smooth bump with gold traces. Rain, splash, condensation all slide off and drain down.sameskydevices+1

• Safety: pogo pins are buried inside the battery dock. Even if a child sticks a finger into the battery's bottom, the recess depth + narrow pin wells make it nearly impossible to touch live contacts.[johotypro]​

• Alignment: the dock cavity on the battery slides over the pad island on the frame. The walls of the dock are the guide — no separate fins or funnels needed. Last few mm of travel compresses the springs onto the pads.[sunkye]​

• Cost: high‑current pogo pins (10A each, gold‑plated) run about $0.18–1.40 per pin depending on quantity. A 6‑pin set on a small PCB inside the battery dock = a few dollars total.[alibaba]​

• Durability: gold‑plated pogo pins handle 10k–100k cycles easily, and the flat pads on the frame side have no wear mechanism at all.attend+1

Pin layout suggestion

For a 36V system at ~10A continuous:

• 2 power pins (paralleled, 10A‑rated each = 20A headroom)

• 1 ground pin

• 1 thermistor / NTC

• 1 communication (UART TX or one‑wire)

• 1 spare / ID

The pad island on the frame side is just a small PCB (~20×15 mm) potted onto a raised plastic pedestal. The battery dock is a matching rectangular cavity with a 6‑pin pogo block soldered to its internal PCB.

This is arguably the simplest, cheapest, and most weather‑resilient swappable battery contact system you could build. Want to start dimensioning the pad island and dock cavity for your DT inner diameter?

That's a really clean inversion. Let me confirm the logic because it's elegant:

The architecture

Side	Component	Why
Down tube (frame)	Elevated flat gold pads on a raised "island"	No moving parts, water sheets off the dome, drains to DT bottom. Nothing to corrode or jam.
Battery	Recessed pogo pins inside a dock cavity	Pins hidden deep inside the battery body — finger‑safe even when battery is out of the bike. Dock walls act as the alignment funnel.

Why this works so well

• Water: the elevated pad island has no cavities for water to pool in — it's just a smooth bump with gold traces. Rain, splash, condensation all slide off and drain down. sameskydevices
• Safety: pogo pins are buried inside the battery dock. Even if a child sticks a finger into the battery's bottom, the recess depth + narrow pin wells make it nearly impossible to touch live contacts. [johotypro](https://www.johotypro.com/pogo-pin-connector/)
• Alignment: the dock cavity on the battery slides over the pad island on the frame. The walls of the dock are the guide — no separate fins or funnels needed. Last few mm of travel compresses the springs onto the pads. [sunkye](https://www.sunkye.com/description-of-pogo-pin-connectors.html)
• Cost: high‑current pogo pins (10A each, gold‑plated) run about $0.18–1.40 per pin depending on quantity. A 6‑pin set on a small PCB inside the battery dock = a few dollars total. [alibaba](https://www.alibaba.com/showroom/pogo-pin-connector-10a.html)
• Durability: gold‑plated pogo pins handle 10k–100k cycles easily, and the flat pads on the frame side have no wear mechanism at all. attend.com

Pin layout suggestion

For a 36V system at ~10A continuous:

• 2 power pins (paralleled, 10A‑rated each = 20A headroom)
• 1 ground pin
• 1 thermistor / NTC
• 1 communication (UART TX or one‑wire)
• 1 spare / ID

The pad island on the frame side is just a small PCB (~20×15 mm) potted onto a raised plastic pedestal. The battery dock is a matching rectangular cavity with a 6‑pin pogo block soldered to its internal PCB.

This is arguably the simplest, cheapest, and most weather‑resilient swappable battery contact system you could build. Want to start dimensioning the pad island and dock cavity for your DT inner diameter?

https://www.pogopinsconnector.com/sale-53243888-3a-spring-loaded-contact-connector-6-pin-2-54-mm-pitch-connector-male-and-female.html pogo pins

https://www.accio.com/plp/6-pin-pogo-pin and https://www.accio.com/d/1601276575888?dataSource=Alibaba.com

Let’s pick a concrete 6‑pin pogo block geometry and then size the pad island around it.

Reasonable 6‑pin pogo block assumptions

Since Accio is an aggregator, we’ll assume a standard 6‑pin block like the common 2.54 mm pitch strips (or equivalent): aliexpress

• Pin pitch: 2.54 mm (center‑to‑center). [ccpcontactprobes](https://www.ccpcontactprobes.com/sites/default/files/2020-01/CCP-Standard-Pogo-Pin-Connector.pdf)
• Pins in a single row (simplest layout).
• Pin count: 6 → total length between outer pins ≈ (5 × 2.54 = 12.7) mm.
• Contact diameter: ≈ 1.3–1.5 mm barrels. [ccpcontactprobes](https://www.ccpcontactprobes.com/sites/default/files/2020-01/CCP-Standard-Pogo-Pin-Connector.pdf)
• Block body length: ≈ 15–18 mm, width ≈ 3–4 mm, height ≈ 6–9 mm typical. johotypro
• Current: 1–3 A per pin, 5 A for some heavy‑duty types. connectors-cables

We can refine once you choose an exact part, but this is good enough to size the island and keep clearances realistic.

Pad island dimensions (frame side)

Assume inner down‑tube width at the bottom is at least 30 mm (you can adjust later). Frame‑side island is a small “speed bump” PCB glued or molded onto a plastic pedestal on the DT floor.

Proposed island:

• Island PCB footprint: 24 mm (L) × 10 mm (W).
• Top surface: gently domed or chamfered edges so water sheds.
• Copper pads area: centered strip about 16 mm (L) × 5 mm (W).

Pad pattern (to match 1×6 pogo row):

• Row along length, pitch 2.54 mm, 6 pads → ~12.7 mm active length.
• Each pad: about 1.5–2.0 mm wide by 2.0–2.5 mm long, with rounded ends.
• Outer keep‑out margin: at least 2–3 mm from island edges so water has “gutters” to flow around the pad zone, not over the pad edges.

Height:

• Island pedestal height above DT floor: 3–4 mm.
• PCB thickness: 1.0–1.6 mm → total ~4–5 mm above the lowest drain point.
• DT floor around the island slopes or is cut away so water naturally bypasses the island and runs along the sides.

Clearances:

• Shortest distance from live pad edge to DT metal: ≥ 3 mm creepage in air (36–48 V is forgiving, but this leaves margin).
• If you pot/overmold the island’s base, you effectively increase creepage along plastic.

Battery dock (pogo side) to match island

Given a 6‑pin row ~12.7 mm long and block ~15–18 mm long:

Dock cavity:

• Internal length: 26–28 mm (island length 24 mm + 1–2 mm margin front/back).
• Internal width: 12–14 mm (island width 10 mm + 1–2 mm margin).
• Depth (from battery bottom opening to pogo contact tips at mid‑stroke): 6–8 mm.
  • Enough that fingers cannot reach pins.
  • Pogo stroke: design contact at ~1/2–2/3 stroke height; e.g. pins 8.8 mm total, 1–2 mm effective stroke. aliexpress

Guides:

• Entry chamfer: dock opening chamfered 30–45° around all edges.
• Side clearance: 0.5–0.75 mm per side between island and dock walls → self‑centering funnel but not too tight for tolerances.

Mounting pogo block:

• Pogo block soldered to a small internal PCB fixed at the top of the dock cavity.
• Vertical offset so at nominal dock engagement, pins compress ~1 mm from free height.

Simple OpenSCAD‑friendly parameters

You can start with something like:

• island_len = 24;
• island_w = 10;
• island_h = 4.5; // pedestal + PCB
• pad_pitch = 2.54;
• pad_n = 6;
• dock_inner_len = island_len + 2;
• dock_inner_w = island_w + 2;
• dock_inner_depth = 7;
• side_clearance = 1;

Then:

• Frame: model a cylinder or oval for DT, subtract a channel at the bottom, then add a rectangular “island” solid with filleted/chamfered edges.
• Battery: a rectangular cavity with those dock_inner_* dimensions, plus chamfers.

Once you pick a specific Accio 6‑pin module with exact pitch and body size, we can tighten these numbers. Do you know your approximate down‑tube inner width at the bottom (e.g. 28, 30, 32 mm), so we can check that the 24×10 mm island still leaves enough drainage on both sides?

I mean to make a dock design you have to understand basics of docking. the battery part is reseeded. the down tube part is elevated. it's not that hard. the bat part has pogo pins. the downntube elevated part has pads.

You’re right: I inverted the roles and made everything confusing.

For a proper dock:

• Battery part is recessed

  • On the battery scaffold bottom you have a shallow cavity.
  • Inside that cavity sit the pogo pins, pointing upward.
  • The cavity walls protect the pins and give lead‑in for docking.

• Downtube part is elevated

  • At the downtube floor you have a raised boss (a small platform) that sticks up into the battery cavity.
  • On top of that boss you have flat pads (no springs).
  • When you drop the battery in, the boss enters the battery cavity, and the pads meet the pogo pins.

Mechanically:

• Gravity pulls the battery down; the recess makes sure the pins are never exposed when the pack is out.
• The elevated boss keeps the frame pads out of any water at the absolute bottom and makes cleaning easy.
• Alignment is trivial: cavity walls guide the boss; the last few mm compress the pogo pins and give the wipe.

I flipped that in the SCAD (pins on the block in the pocket, plug above), so the picture you see is wrong from a docking‑mechanics standpoint.

Here’s a very small, self‑contained OpenSCAD snippet that models:

• A cylindrical down tube section.
• The raised pad island on the inside bottom.
• The matching battery dock cavity with pogo block above.

You can paste this into a new .scad file and tweak dimensions.

// Simple demo of pad island + recessed pogo dock
// Units: mm

$fn = 64;

// ---------- Parameters ----------
dt_inner_d   = 30;    // down tube inner diameter
wall_thick   = 2;     // tube wall
section_len  = 60;    // length of shown tube section

island_len   = 24;
island_w     = 10;
island_h     = 4.5;   // pedestal + PCB

dock_depth   = 7;
dock_clear   = 1;     // clearance around island inside dock

pogo_block_h = 3;     // pogo plastic height

// ---------- Main ----------
module down_tube_section() {
    difference() {
        // outer tube
        cylinder(h = section_len, r = dt_inner_d/2 + wall_thick, center = false);
        // inner bore
        translate([0,0,0])
            cylinder(h = section_len, r = dt_inner_d/2, center = false);
    }
}

module pad_island() {
    // Island at bottom inside tube (z = 0 plane is bottom)
    translate([0, 0, 0]) {
        // Use a rounded box as pedestal+PCB
        translate([0, 0, island_h/2])
            rounded_box([island_len, island_w, island_h], r = 1.5);
    }
}

module rounded_box(size = [10,10,5], r = 1) {
    // quick-and-dirty rounded rectangle prism
    hull() {
        for (sx = [-1, 1])
            for (sy = [-1, 1])
                translate([sx*(size[0]/2 - r), sy*(size [reddit](https://www.reddit.com/r/openscad/comments/1lowpyi/designing_connecting_cubes/)/2 - r), 0])
                    cylinder(h = size [hackster](https://www.hackster.io/chloe-hor/building-a-reliable-magnetic-pogo-pin-usb-charging-interface-2efafd), r = r, center = true);
    }
}

// Battery dock cavity that drops over the island
module battery_dock() {
    // We show only the dock “block” here, not the whole battery.
    dock_len = island_len + 2*dock_clear;
    dock_w   = island_w   + 2*dock_clear;

    // Position the dock above the island, leaving some air gap.
    translate([0, 0, island_h + 2]) {
        // Outer block (for visualisation)
        color("lightgray")
        difference() {
            // Solid block representing the battery bottom
            cube([dock_len+6, dock_w+6, dock_depth+5], center = true);

            // Hollow cavity that fits around the island
            translate([0, 0, -1]) // cavity starts a bit above bottom
                cube([dock_len, dock_w, dock_depth], center = true);

            // Simple chamfer / funnel: subtract a slightly rotated hull
            // (kept crude for simplicity)
        }

        // Pogo block “inside” roof of cavity
        pogo_len = island_len - 4;
        pogo_w   = 4;
        translate([0, 0, dock_depth/2 - pogo_block_h/2])
            color("silver")
            cube([pogo_len, pogo_w, pogo_block_h], center = true);
    }
}

// ---------- Assembly views ----------

// Uncomment ONE of these at a time:

// 1) Frame only with island
//rotate([90,0,0]) {
//    translate([0,0,-section_len/2])
//        down_tube_section();
//    pad_island();
//}

// 2) Frame + dock in position
rotate([90,0,0]) {
    translate([0,0,-section_len/2])
        down_tube_section();
    pad_island();
    battery_dock();
}

This is intentionally simple and blocky: it just shows the relationships and clearances. You can now:

• Adjust diameters/lengths to match your actual DT and battery scaffold.
• Replace the battery_dock() solid with your real battery bottom geometry and fuse this dock into it.

Want me to add a second module that shows just the pad island and its PCB as a 2D projection you can export as DXF for the copper pattern?

that's cool 2 things. 1. only 1 dock and one island. dont make double sets. 2. the island must be square. dont chafer it. and recede the pins way more into the dock. human fingers cant reach it. also make the island smaller. so the dock is narrower. safetysafetysafetysafetysafety