Philips CPJ-810 AR8378BK01 Compatible Battery 12V 1800mAh

Philips CPJ-810 / CPJ-815 / CPK-834 Series — 12V Ni-MH Replacement Battery (AR8378BK01)

This is a 12V, 1800mAh Ni-MH replacement battery for Philips CPJ-810, CPJ-815, CPK-834, CPK-855, and related camera models. It replaces OEM part numbers AR8378BK01, AR8395BK01, V80039BK01, and V80086BK01 among others. Capacity is rated at 21.6Wh, matching the original cell specification.

• CPJ and CPK platform compatibility: These Philips camera models share the same 12V battery rail, connector pinout, and BMS handshake protocol. A single cell format covers the full CPJ-810 through CPK-855 range because Philips standardised the battery interface across that generation.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a camera body, confirming the BMS accepted the replacement without flagging an incompatible cell error. Voltage delivery stayed within tolerance across the full discharge curve.
• First-install charge cycle for Ni-MH cells: Ni-MH chemistry in camera bodies benefits from running the initial charge through the OEM charger or camera body itself — not a generic charger. This allows the BMS to map the cell's discharge curve and return an accurate battery-remaining reading during shooting.

Camera showing dead battery indicator on a partially charged replacement cell

Philips CPJ and CPK bodies use a voltage-threshold method to estimate remaining charge. A new Ni-MH cell has a flatter discharge curve than a worn original, so the camera's indicator can misread state-of-charge early on. The BMS maps thresholds against a stored discharge profile, and a fresh cell doesn't match that stored curve until it's been cycled once. Run one full charge-to-discharge cycle through the camera body, then recharge fully. After that cycle, the indicator reading stabilises to within a normal range.

Flash not fully recycling between shots on a new Ni-MH cell

Flash recycle relies on the battery sustaining current delivery while the capacitor recharges. At the tail end of a discharge cycle, internal resistance in Ni-MH cells rises, and capacitor recharge time increases noticeably. If recycle lag appears earlier than expected, check the cell's resting voltage — it should read above 10.8V under no load to confirm sufficient charge remains. Recharge before the cell drops below that threshold to avoid repeated capacitor recharge lag mid-shoot.