BenQ NP-40 DC P500 Replacement Battery 3.7V 1100mAh

BenQ DC P500 / P600 / E510 / E520 — 3.7V Li-ion Replacement Battery (NP-40)

This is a 3.7V, 1100mAh Li-ion replacement cell for the BenQ NP-40 battery slot. It fits the DC P500, P600, E510, E520, and two additional BenQ compact camera models that share the same NP-40 form factor. Voltage and capacity match the original spec exactly.

• NP-40 platform compatibility: These BenQ models share the same cell footprint, connector pin-out, and BMS handshake protocol — that is why one part number covers the full range. The 38.25 × 38.15 × 9.50mm cell dimensions keep the door latch seated correctly across all listed bodies.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the DC P500 body. The BMS accepted the cell without fault codes, reported state of charge accurately across the discharge curve, and held the cut-off voltage cleanly at the low-voltage threshold.
• First-install charge cycle on BenQ bodies: Run one complete charge inside the camera body or OEM charger before heavy shooting. BenQ's battery-remaining indicator maps to a learned discharge curve — skipping this step causes the percentage counter to jump erratically in the first session.

Dead battery indicator showing on a partially charged NP-40 replacement

BenQ compact cameras track remaining charge by comparing real-time cell voltage against a stored discharge curve from the last full cycle. A brand-new cell has no stored curve, so the camera maps voltage to the wrong point on its reference table. The display reads empty even when the cell holds usable charge. One full charge-from-flat cycle inside the camera body writes a new reference, and the indicator calibrates correctly from that point forward.

Flash recycling slowing down mid-shoot with a new cell

The built-in flash capacitor on these BenQ compacts draws a sharp recharge current spike after each fire. At the beginning of a session, the cell delivers that spike without voltage sag. As the cell discharges below roughly 3.5V, internal resistance rises enough that the capacitor recharge cycle takes noticeably longer. This is a cell-state issue, not a flash unit fault. If recycling slows early in a session, check that the replacement cell completed a full initial charge cycle — a cell pulled from storage at partial charge shows the same symptom.