About this replacement
Insta360 Ace / Ace Pro — 3.85V Li-ion Replacement Battery (CINSBAJA)
This is a 3.85V, 1750mAh Li-ion replacement battery for the Insta360 Ace and Ace Pro action cameras. It matches the OEM part number CINSBAJA and fits the original battery slot without modification. Swap it in when your original cell no longer holds a usable charge through a full shoot.
- Ace and Ace Pro compatibility: Both cameras share the same battery bay dimensions, connector pinout, and BMS communication protocol — that is why one cell covers both models. The 3.85V nominal voltage matches the power rail each body expects, so the camera's charge controller reads and manages the cell correctly.
- Bench tested on actual hardware: We cycled this cell through the Ace Pro body using the OEM USB-C charge path and confirmed the BMS accepted the cell, reported charge state, and completed a full charge-to-cutoff sequence without error flags.
- First-use charge cycle on the Ace: Before shooting heavily, run one full charge cycle directly inside the camera body via USB-C — not a third-party hub. Some Insta360 BMS firmware versions require an in-body charge cycle to calibrate the battery-remaining display to the new cell's discharge curve.
Battery percentage jumping erratically on the Ace display after fitting a new cell
The Ace maps its battery indicator to a fixed voltage-threshold table tuned to the original cell's discharge curve. A new cell — even one with identical specs — can sit at a slightly different voltage point mid-discharge than the camera expects, causing the indicator to skip. This is a calibration issue, not a fault with the cell. Run two full charge and discharge cycles through the camera body and the indicator tracking tightens up as the BMS builds a fresh reference map.
Insta360 Ace showing a dead battery icon on a cell that still has charge
This happens when the camera's BMS authentication check does not complete on first install — typically because the cell has not yet been charged through the camera's own charge controller. The body reads an unrecognised voltage signature and flags it as empty rather than unknown. Connect the camera to USB-C power with the new cell installed and let it charge to 100% before powering on to shoot. After one full in-body charge cycle, the camera will read and display the cell's state correctly.