Speed D1 Camera Replacement Battery 3.7V 1050mAh Li-ion

Speed D1 / D2 / D5 / D6 Series — 3.7V Li-ion Replacement Battery

This is a 3.7V Li-ion replacement battery with 1050mAh (3.89Wh) capacity for the Speed D1, D2, D5, and D6 camera models, plus five additional compatible models in the same series. It slots into the battery compartment to restore power to the camera body for photo and video capture. No OEM part number is published for this cell.

• D1 / D2 / D5 / D6 series fit: These models share the same battery bay dimensions, contact layout, and 3.7V operating rail. The BMS in each body expects the same voltage curve, so one cell covers the full range without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a camera body. The BMS accepted the cell after one full charge cycle, reported a stable voltage reading, and held the protection circuit within normal cutoff thresholds throughout.
• First-install charge cycle: Run the first charge from inside the camera body or the OEM charger — not a third-party USB adapter. Some Speed bodies require an in-body charge cycle before the battery-remaining indicator maps correctly to the new cell's discharge curve.

Flash capacitor recharge pulling voltage down mid-shoot

The built-in flash on compact camera bodies like the Speed D-series draws a sharp current spike each time the capacitor recharges between shots. At 3.7V nominal, a 1050mAh cell handles this well early in the discharge curve. Near the end of charge, internal resistance rises and the voltage sags briefly under that capacitor load. The camera may display a low-battery warning even though the cell isn't fully depleted. If flash recycle time slows noticeably, the cell is approaching the lower cutoff — charge before the next session rather than continuing to shoot.

Battery percentage jumping or dropping suddenly on the display

This happens when the camera's fuel gauge maps its percentage thresholds to the OEM cell's discharge curve, which differs slightly from the replacement cell's curve. The camera reads the same voltage point and assigns a different percentage than expected. It's a calibration artefact, not a cell fault. Run two or three full charge-to-cutoff cycles through the camera body and the indicator will stabilise as the BMS re-learns the discharge profile.