Acer NP-900 Digital Camera Replacement Battery 3.7V 600mAh

Acer CS 6531-N — 3.7V Li-ion Replacement Battery (NP-900)

This is a 3.7V, 600mAh Li-ion cell for the Acer CS 6531-N compact digital camera. It replaces OEM part numbers NP-900, 02491-0015-00, BATS4, and 02491-0037-00. The cell fits the CS 6531-N body directly and communicates with its battery management system over the standard NP-900 contact layout.

• CS 6531-N fitment: The NP-900 form factor — 43.70 × 31.30 × 7.00mm — is specific to this compact camera platform. The three-contact terminal arrangement carries both power and the signal line the camera body uses to read charge state. A cell outside this exact footprint will not seat correctly in the battery bay.
• Bench tested on actual hardware: We cycled this cell through the CS 6531-N body using the OEM charger. The BMS handshook on first charge without prompting a compatibility error, and the charge-state indicator tracked the discharge curve through to cutoff.
• First-use charge cycle on the CS 6531-N: Run one full charge cycle inside the camera body before your first shoot. The CS 6531-N maps its battery-remaining display to a charge curve it records during that initial cycle — skipping it can cause the indicator to read inaccurately for several sessions afterward.

Flash recycling slowing down toward end of charge on the CS 6531-N

The CS 6531-N flash capacitor draws a concentrated burst of current each time it recharges between shots. As cell voltage drops below roughly 3.5V, the available current for capacitor recharge decreases noticeably. The result is a longer wait between flashes — not a fault in the cell itself, but a natural consequence of the discharge curve. If recycling time is increasing, check the battery-remaining indicator; the cell is likely in its final 15–20% of capacity.

Battery percentage jumping on the display after fitting a new cell

The CS 6531-N reads remaining charge by mapping current cell voltage against a stored discharge curve. A new cell's discharge curve can differ slightly from the OEM cell the camera calibrated against, causing the indicator to jump — for example, dropping from 80% to 50% without warning. This is a display calibration issue, not a cell fault. Perform two full charge-and-discharge cycles inside the camera body; the indicator typically stabilises as the BMS updates its internal reference points.