About this replacement
Custom Battery Pack INR18650 2S3P — 7.4V Li-ion Replacement Battery
This is a 7.4V 10200mAh (75.48Wh) lithium-ion pack built in a 2S3P configuration — two cells in series, three in parallel. It replaces degraded or failed OEM packs matching the INR18650 2S3P cell arrangement and voltage rail. Before installing, confirm your original pack runs at 7.4V nominal and shares the same connector pinout.
- 2S3P cell architecture: Three parallel cell groups step up current capacity while two series cells set the 7.4V nominal rail. Any replacement must match both figures — swapping to a different series count shifts the voltage and can trip the host device's over-voltage protection.
- Bench tested on actual hardware: We ran charge and discharge cycles on this pack and monitored the integrated BMS. The protection circuit held cutoff at the expected thresholds for over-charge, over-discharge, and short-circuit events without nuisance tripping.
- First-cycle calibration: If your device has a fuel gauge or capacity indicator, run one full charge-to-discharge cycle after installation. The gauge IC calibrates its state-of-charge model against the new cells — skipping this leaves the reading inaccurate for several subsequent cycles.
Pack running at lower voltage than rated on first use
INR18650 cells ship at storage voltage — typically 3.6–3.7V per cell, putting a 2S pack around 7.2V at rest. That is below the 7.4V nominal figure and can cause some host devices to report a low-battery condition immediately. Charge the pack fully before the first use. After a complete charge cycle, resting voltage should sit at approximately 8.4V and nominal under load will settle at 7.4V.
Pack not reaching full charge on first cycle
On first charge, the charge IC may apply a reduced current rate — a conditioning behaviour on new cells where the controller verifies cell impedance before delivering full current. The pack will appear to plateau below 8.4V and the charger may terminate early. Disconnect, let the pack rest for five minutes, then restart the charge. By the second or third cycle the charge IC lifts the current limit and the pack reaches full voltage consistently.