Samsung HMX-S10 Camcorder Replacement Battery IA-BP420E 3.7V

Samsung HMX-S10 / HMX-H200 Series — 3.7V Li-ion Replacement Battery (IA-BP420E)

This is a 3.7V 3600mAh Li-ion replacement cell for the Samsung IA-BP420E battery pack. It fits the HMX-S10, HMX-S15, HMX-S16, HMX-H200, and over 24 additional Samsung camcorder models that share this battery platform. Dimensions are 45 × 33 × 35mm — measure your existing pack if you are unsure before ordering.

• HMX-S and HMX-H platform compatibility: These models share a common 3.7V single-cell architecture with the same connector pinout and BMS communication protocol. One cell works across all of them because Samsung standardised the battery interface across this compact camcorder range.
• Bench tested on actual hardware: We ran this cell through the HMX-S10 body and monitored BMS handshake, charge acceptance, and cutoff thresholds. The protection circuit triggers correctly at low-voltage cutoff and the camera body accepted charge termination without error flags.
• First-use charge cycle on HMX camcorders: Insert the new cell and charge it fully inside the camera body before your first recording session. The HMX BMS maps its battery-remaining display against a charge curve it builds during that first in-body cycle — skipping this step causes the indicator to read inaccurately from the start.

Battery percentage jumping erratically on the HMX-S10 display

The HMX-S10 battery indicator is calibrated against a specific discharge voltage curve that Samsung set for the original IA-BP420E cell. A new replacement cell — even one with identical specs — has a slightly different voltage-to-capacity profile until it is cycled. The BMS reads the instantaneous voltage and maps it to a percentage using the factory curve, so mismatches cause the indicator to jump or drop suddenly. Run two full charge-discharge cycles through the camera body and the display stabilises as the BMS updates its internal reference.

HMX camcorder showing no battery detected after fitting a new cell

The HMX series performs a basic authentication check on insertion — if the BMS on the replacement cell is in a sleep state from storage, the camera body may read it as absent. Remove the battery, reinsert it firmly, and attempt a charge via the camera body rather than an external charger. A full charge from the camera body wakes the protection circuit and clears the authentication flag. If the body still shows no battery after one charge attempt, check that the terminal contacts on the cell and camera door are clean and making flush contact — even a fraction of a millimetre gap drops the signal below the 3.0V detection threshold.