Phiten CN100001 Replacement Battery 3.7V 2600mAh

Phiten CN100001 — 3.7V Li-ion Replacement Battery (INR18650-22S)

This is a 3.7V, 2600mAh Li-ion replacement battery for the Phiten CN100001 personal care device. It uses an INR18650-22S cell format and slots into the original battery compartment. When the original cell no longer holds adequate charge, this is the direct cell swap.

• CN100001 platform fit: The CN100001 runs a single-cell 3.7V nominal rail with a BMS that monitors voltage at both ends of discharge. The INR18650-22S matches that rail exactly — voltage, form factor (68 × 19 × 19mm), and cell chemistry all align with what the stock BMS expects to see.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a cell tester, confirmed the protection circuit trips at the correct over-discharge threshold, and verified the cell holds full rated capacity at 2600mAh before shipping.
• Port hygiene after use near moisture: Dry the charging port fully before connecting after any use near water. Moisture bridging the charging contacts causes the BMS to trigger a protection fault that registers as a dead battery — not a charging error — and can lock the cell out of charging entirely until the fault clears.

Motor power dropping before the battery indicator shows low

The CN100001 motor draws a short current spike at startup, which causes a brief voltage sag on the cell. An aged or partially degraded cell sags further than a fresh one — far enough that the BMS reads it as approaching the low-voltage cutoff and reduces output before the fuel gauge catches up. The indicator LED reflects average voltage, not the instantaneous sag under load. A fresh INR18650-22S cell with lower internal resistance handles that startup spike without sagging past the BMS threshold, restoring full motor power from the first press.

Device not charging after moisture exposure

Moisture on the charging contacts can cause a short across the port that the BMS interprets as a fault condition, latching the protection circuit open. In that state the device accepts no charge and shows no charging indicator — it looks dead. Let the port air-dry completely, then attempt a charge. If the cell voltage has dropped below 2.5V during the lockout period, some chargers won't initiate — use a charger that supports a low-voltage recovery or pre-charge mode to bring the cell back above 3.0V first.