HP Photosmart R507 Replacement Battery A1812A 3.7V 1050mAh

HP Photosmart R507 Series — 3.7V Li-ion Replacement Battery (A1812A)

This is a 3.7V Li-ion replacement battery rated at 1050mAh (3.89Wh), built to the same electrical spec as OEM part A1812A. It fits the HP Photosmart R507, R607, R607 BMW, R607 Gwen, and more than 19 additional Photosmart compact camera bodies. Swap it in when your original cell no longer holds a charge through a full shoot.

• Photosmart R-series compatibility: These camera bodies share the same battery bay dimensions, 3.7V power rail, and BMS handshake protocol. Any body that accepts OEM part A1812A or L1812A will accept this cell without modification.
• Bench tested on actual hardware: We cycled this cell through the R507 body using its OEM charger. The BMS accepted the cell on first insertion, charge termination triggered correctly at full voltage, and discharge draw through the LCD and sensor stayed consistent across multiple cycles.
• First charge protocol on the R507: Run the first full charge cycle inside the camera body via the OEM charger, not a third-party external charger. The R507's BMS maps the battery-remaining indicator against the charge curve it logs during that first cycle — skipping this step causes the indicator to read inaccurately throughout the cell's life.

Dead battery indicator on the R507 with a partially charged replacement cell

The R507 displays a dead battery warning when the cell voltage drops below its low-voltage threshold, even if the cell still carries usable charge. A new Li-ion cell has a slightly different discharge curve than an aged OEM cell, so the camera's threshold mapping can trigger the warning early. This is a calibration issue, not a faulty battery. Run one full charge-discharge cycle inside the camera body to let the BMS recalibrate its voltage-to-percentage mapping to the new cell.

Battery percentage jumping erratically on the Photosmart display

Erratic percentage readings happen when the camera's fuel gauge hasn't mapped the new cell's discharge curve yet. The R507 uses a voltage-threshold system — it reads a voltage point and translates it to a percentage based on stored OEM reference data. A fresh cell discharges differently at each threshold, so the percentage can jump several steps at once. Charge the cell fully in the camera body, run it down through normal shooting without removing it mid-cycle, then recharge fully — one complete cycle resets the reference map.