Ambarella A7LS Compatible Battery 3.7V 850mAh Li-ion

Ambarella A7LS — 3.7V Li-ion Replacement Battery

This is a 3.7V, 850mAh Li-ion cell for the Ambarella A7LS action camera. It replaces the original internal battery used for continuous video recording in dash cam and sports camera applications. Dimensions are 36.35 × 32.30 × 7.82mm — confirm these against your existing cell before fitting.

• A7LS platform fit: The A7LS processor handles continuous H.264 encoding alongside sensor readout — both draw from the same 3.7V rail. This cell matches the original voltage and form factor so the board receives stable current during sustained recording bursts.
• Bench tested on actual hardware: We cycled this cell through charge and discharge while monitoring BMS behaviour at the low-voltage cutoff. The protection circuit tripped cleanly at the expected threshold with no anomalous shutdowns during continuous load.
• First-cycle conditioning on the A7LS: Run one complete charge cycle through the camera body or OEM charger before heavy recording sessions. Some A7LS units recalibrate their fuel gauge against the new cell's discharge curve during that first cycle, which keeps the battery indicator accurate from the second session onward.

Why the A7LS battery indicator reads full then drops suddenly mid-clip

The A7LS maps its battery-remaining display to a voltage-threshold table calibrated to the original cell's discharge curve. A new replacement cell — even one with identical chemistry — can have a slightly different voltage slope through the mid-range. The camera reads the new curve as "full" longer than expected, then drops several bars at once when voltage falls through a mapped threshold. One full charge-discharge cycle inside the camera body allows the firmware to re-anchor its reference points to the new cell's actual curve.

Camera shows dead battery icon on a freshly charged replacement cell

This happens when a replacement cell ships in a deep-discharge state — typically below 2.8V — and the A7LS BMS reads it as a failed or absent cell rather than a depleted one. Connect the battery to an OEM-compatible charger externally for 10–15 minutes to bring the cell above 3.0V before inserting it into the camera body. Once above that threshold, the camera will recognise the cell and accept a normal charge. If the camera still shows a dead battery icon after pre-charging, check that the cell contacts are fully seated and free of debris.