# Passive battery adapter: carrier fabrication and termination

**One additional passive carrier connects the intact factory battery plug to the two CK pigtails.** Fabricate the carrier below and install the existing B2B-PH header in its fixed CAD pose. This is a mechanical fabrication specification with electrical and first-article checks still required.

Use the [dimensioned drill/pad drawing](ADAPTER_CARRIER_DRILL_AND_PAD_DRAWING.svg) and [two-connection diagram](ADAPTER_TWO_ISOLATED_NETS_AND_TERMINATION.svg) alongside this document. PNG previews are included below. The drill drawing is dimensioned; the termination section explains the connection and is not a solder-joint template.

## Why the carrier reference changed

The supplied copied header has its actual tails at **X21 and X23, Z−6.7 mm**. The earlier carrier had holes at Z−7.3 mm, which intersected those pins by **0.6432 mm³**. The corrected hole row clears the imported pins. The carrier's finished outside size and pose remain **8 × 6 × 1 mm**, at X18…26, Y−5…−4, Z−10.3…−4.3. The header, main PCB headers, factory battery lead and factory plug stay in their original assigned poses.

## Manufacturer information and design choices

The [JST PH manufacturer drawing](https://www.jst-mfg.com/product/pdf/eng/ePH.pdf) specifies 2.00 ±0.05 mm pitch, a reference through-hole pattern of Ø0.7 +0.1/0 mm, and board thickness 0.8…1.6 mm. Its notes allow consideration of larger holes in hard fiberglass boards. The top-entry drawing's 1.7 mm edge-to-pin-row dimension agrees with the imported header's asymmetric pin row. These manufacturer dimensions are distinct from the following carrier fabrication choices.

| Feature | R3.6 carrier requirement |
|---|---|
| Quantity / material | 1 fabricated FR4 carrier; not a printed plastic part |
| Finished size | 8.00 × 6.00 × 1.00 mm; target ±0.05 mm on outside dimensions |
| Finished stack | The 1.00 mm thickness includes copper, finish and solder mask; do not add copper thickness outside this finished envelope |
| Hole count / type | Two plated-through holes |
| Finished hole | Ø0.95 ±0.03 mm, measured after plating; this is the chosen clearance hole, not the JST nominal reference hole |
| Local hole centers | A: (u,v)=(3.00,3.60); B: (5.00,3.60) mm |
| Position control | Hole center true position within Ø0.06 mm of the local datums; 2.00 ±0.05 mm pitch, noncumulative |
| Pads | Ø1.60 mm plated pads on both faces, connected only through their own plated barrel; no traces, copper pour or cross-link between A and B |
| Nominal pad separation | 0.40 mm copper edge-to-edge; inspect isolation after soldering |
| Nominal annulus | 0.325 mm, or 0.310 mm at the largest allowed finished hole |
| Marking | Mark A and B on non-contact FR4 outside the pads, within the finished outline |

Local coordinates are viewed from the **solder side, Y<−5, looking +Y**, with +X to the right and +Z upward. Map them to the assembly with **u=X−18, v=Z+10.3**. The hole axes run along Y. A is X21/Z−6.7; B is X23/Z−6.7. These geometric A/B labels do **not** establish positive/negative or electrical pin numbering.

The imported tail is approximately 0.6 mm rounded square. Its minimum nominal clearance to the Ø0.95 bore is **0.0714 mm** in the modeled through-board section. That is a CAD check, not a guarantee for the bought header. Fit a received header to a finished sample carrier before population. Both tails must enter freely; do not force, splay or clinch them to correct a drilling error.

## Two separate connections

Each CK conductor solders **directly to its matching metal header tail**. Its plated pad mechanically anchors that tail. No PCB trace is used or credited as the current path. Each branch has its own insulating sleeve and covered rear pad. The assembled A and B circuits remain isolated from each other.

The intended outgoing stock is 26 AWG stranded conductor, with the installed insulated routes bounded at Ø1.05 mm. One primary example is [Tonichi Kyosan UL1061 SPE-34B](https://www.tonichi-kyosan.co.jp/product/equipment_ul1061/index.html), whose 26 AWG construction is 7/0.16 mm and approximately Ø0.98 mm finished. That is an example, not a selected qualified lot. The bought wire must meet the routed diameter, connector and soldering requirements.

For each tail at X21 or X23:

- The insulated CK jacket endpoint stays at Y−9.5, Z−7.3. Fit the separate split-silicone pigtail clamp to the jacketed portion; it must not clamp bare copper or solder.
- The bare-core reference is Ø0.48 mm and follows (Y,Z)=(-9.5,-7.3) → (-8.1,-7.24) → (-5.8,-7.24), with a smooth transition. It provides approximately **3.7 mm** of exposed-core path for fitting; establish the actual strip length on the sample without nicking strands.
- The source tail tip is at Y−7.5. Its full 0.6 mm section is present by Y−7.0. Place the core along the underside at Z−7.0, giving approximately **1.2 mm of full-section direct lap** from Y−7.0 to −5.8. Confirm solder wetting and useful overlap on the received part; do not treat a CAD tangent as a solder-quality check.
- Keep solder, fitted heat-shrink insulation and any pad coating inside `R36_ADAPTER_CORRECTED_TAIL_AND_PAD_INSULATION_FINAL.step`. Its main sleeve is Ø1.8 mm along the supplied curved path and its rear pad covering is bounded by Ø1.8 × 0.15 mm at Y−5.15…−5.0. The front pad lies beneath the seated header; do not build an extra solder mound beneath the housing.
- The two maximum installed insulating envelopes have **0.20 mm nominal separation**. Check the actual finished sleeves for bridges, exposed metal, pinholes and abrasion. Select electrically insulating materials compatible with the chosen soldering process; material, shrink ratio and coating cure remain qualification items.

The completed joint envelope is X20.10…23.90, Y−9.9587…−5.0, Z−8.2221…−5.8 mm. The tiny modeled core overlap with its own CK route represents the continuous conductor entering the jacket. Header-tail overlap with the insulating envelope is intentional. Neither envelope is a solid object to manufacture or print.

## Electrical and mechanical qualification

JST lists **2 A with AWG24** for this connector family. That is not an automatic 2 A rating for this 26 AWG adapter, its direct-lap joints, the battery or the complete harness. No PCB trace ampacity is assigned because the intended current passes through the direct wire-to-pin lap. Confirm the actual operating and charging currents, selected wire/contact ratings, voltage drop, joint temperature and strain retention before release. This document does not establish a current limit for the unqualified assembled adapter.

1. Work with the battery disconnected and the main PCB/module removed. Thread the two manufactured bare pigtail ends through the loose final K03 passage before soldering or fitting the finished termination insulation. Then form the two direct-lap joints and fit their controlled insulation as a complete loose module. Establish the main board's battery input mapping from the board documentation and continuity checks. Verify the actual factory plug's polarity at its contacts. Record which geometric A/B path goes to each required net; do not infer it from this viewing direction or wire color alone.
2. Verify continuity through A only and B only, and isolation between A/B and adjacent hardware, before plugging in the battery. Inspect solder joints and insulation under magnification.
3. Preassemble the soldered carrier, header, corrected insulation, four 0.25 mm edge pads, split grommet and final K03 outside the shell. Insert that complete module from the open rear before installing the main PCB, with the manufactured pigtail undressed and factory battery plug disconnected. The separate cover cannot slide past fixed solder joints. Grip header/plug bodies during mating and removal.
4. With the complete module on its padded locating faces and hard supports, check that the split-silicone clamp grips insulated jacket and fasten K03 through the open rear using the final adapter hardware schedule. The main PCB must remain absent for these straight driver paths. Qualify the clamp with the fixture's **5 N service-pull and 10 assembly/service-cycle screen**, checking that loads do not reach the lap joints or loosen the header. The printed seat coupon tests the seat and clamp; it does not qualify solder joints or electrical performance.
5. Check the finished carrier size, free header fit, seated height, sleeve spacing and case closure on the first article. Reject a part that requires force, pin bending, insulation compression against hard hardware, or an enlarged exterior.

## Verified CAD checks and limits

`adapter_fabrication_final_verification.json` checks the corrected carrier, termination envelope and bare-core references against the original fixed electronics, current controls/PCB/battery parts, all current fixture routes, all J9 routes/joints/supports, the revised seat, rear-access K03 and its screws. The check found **zero unintended intersections**. Expected contacts are the carrier's four soft pads and seated header, and each continuous conductor/termination envelope.

| Checked clearance | Nominal result |
|---|---:|
| Carrier to revised hard seat / K03 | 0.25 mm; pads occupy the intended contact gap |
| Carrier to final right rear-access screw envelope | 0.3479 mm; right axis X28.1 |
| Corrected insulation to final K03 | 0.36 mm; final cover hash 580eec |
| Corrected insulation to split-silicone clamp | 0.3414 mm |
| Insulating branch A to branch B | 0.20 mm |
| Exposed source tail volume outside insulating envelope | 0 mm³ |
| Bare-core reference volume outside insulating envelope | 0 mm³ |

The fabrication audit originally tested an earlier right-screw pose. The final receiver correction moves that axis to X28.1; `ADAPTER_SEAT_CANDIDATE_CHECKS.json` records 0.347871 mm to the carrier and 0.247221 mm to the installed rear edge pad. `ADAPTER_LATEST_FINAL_PAIR_CHECKS.json` also checks the corrected carrier and insulation against the final host and cover. The final reinforced cover 580eec subsequently uses a rounded termination opening with 0.36 mm clearance. The frozen fabrication source and manifest remain unchanged.

These checks apply to nominal CAD and the specifically hashed source files. They do not certify the printed material, bought components, soldering, insulation, electrical behavior or repeated handling.

## Final reference replacements

Use `ADAPTER_FABRICATION_FINAL_MANIFEST.json`. It replaces the obsolete carrier and termination allowance with:

- `R36_ADAPTER_FR4_8x6x1_CORRECTED_PIN_ROW_FINAL.step` — fabricated passive carrier.
- `R36_ADAPTER_CORRECTED_TAIL_AND_PAD_INSULATION_FINAL.step` — maximum installed termination envelope, reference only.
- `R36_ADAPTER_TWO_BARE_LAP_CONDUCTORS_REFERENCE_FINAL.step` — core placement reference, reference only.

The separate final adapter seat/cover manifest governs shell operations and screws. This carrier correction adds no shell operation, changes no exterior, and moves no header, factory plug or factory battery lead.

## Drawing previews

![Dimensioned adapter carrier drill and pad drawing](ADAPTER_CARRIER_DRILL_AND_PAD_DRAWING.png)

![Two isolated connections and termination section](ADAPTER_TWO_ISOLATED_NETS_AND_TERMINATION.png)