Custom Battery Packs 1ICP4/25/37 Compatible Battery 3.7V 320mAh

Custom Battery Packs 1ICP4/25/37 — 3.7V Li-Polymer Replacement Battery

This 3.7V, 320mAh (1.18Wh) lithium-polymer cell replaces the OEM pack identified by part number 1ICP4/25/37. At 35.00 × 22.50 × 4.30mm, it matches the original footprint for a direct physical swap. Verify your original pack's part number against 1ICP4/25/37 before ordering.

• OEM part number match: Devices using the 1ICP4/25/37 pack share a defined voltage rail at 3.7V nominal and a connector pinout tied to that form factor. Swapping to any cell outside that voltage window or footprint will cause fit or recognition failures.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench, confirming the BMS reaches full charge cutoff at 4.2V and triggers low-voltage protection before cell damage occurs. Capacity matched the rated 320mAh within normal tolerance.
• First-cycle calibration: After installing, run one full charge-to-discharge cycle before trusting any capacity indicator reading. Battery packs with integrated fuel gauges need this cycle to recalibrate against the new cells — skipping it causes the gauge to read inaccurately from the start.

Pack not accepted by device after swap

Some compact devices run a voltage range check or BMS handshake on power-up before accepting a new pack. A freshly shipped lithium-polymer cell sits at storage voltage — typically 3.6–3.7V — which can fall just outside the window the device expects at boot. Connect the pack to a charger first and bring it to a full 4.2V charge before inserting it into the device. If the device still rejects it, power-cycle the host device with the pack seated and retry.

Pack not reaching full charge on the first cycle

On the first charge, the charge IC often limits current while it characterises the new cells, which means the pack may terminate early or show a lower-than-expected charge level. This is a conditioning behaviour, not a defect. Run one complete charge cycle through to termination, then discharge the device normally and recharge fully. Capacity and charge acceptance normalise after that first complete cycle.