About this replacement
Astak Action Pro 3 / CM-7500 — 3.7V Li-ion Replacement Battery (752836)
This is a 3.7V, 900mAh Li-ion replacement battery for the Astak Action Pro 3 and CM-7500 action cameras. Part number 752836 matches the OEM cell specification. Swap it in when the original cell no longer holds a usable charge between recording sessions.
- Action Pro 3 and CM-7500 compatibility: Both models share the same battery bay dimensions and 3.7V single-cell Li-ion voltage rail. The 752836 part number covers both. The connector orientation and BMS handshake profile are identical across the two.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Action Pro 3 body. The BMS accepted the cell without fault flags, and voltage under recording load held within expected range for a 900mAh cell.
- First-cycle initialisation on the Action Pro 3: Charge this battery fully inside the camera body or OEM charger before your first recording session. Some compact action camera BMS controllers need one complete in-body charge cycle to map the new cell's discharge curve accurately for the battery indicator.
Battery percentage jumping on the Action Pro 3 display after fitting a new cell
The Action Pro 3 maps its battery indicator to a fixed voltage-threshold table calibrated to the original cell's discharge curve. A fresh replacement cell discharges on a slightly different curve until the BMS has logged a full cycle. This causes the indicator to skip steps or drop suddenly — the cell itself is fine. Run one complete charge from empty to full inside the camera body, and the display will stabilise to a more accurate readout.
Action Pro 3 showing a dead-battery icon on a partially charged replacement cell
This happens when the camera's BMS reads the resting voltage of a new or stored cell and flags it as depleted before checking load voltage. A cell that has been in storage can sit below the camera's minimum acceptance threshold — typically around 3.0V on this platform. Connect the battery to an OEM-compatible charger externally first and bring it up to at least 3.6V. Once voltage is above the acceptance window, insert it into the camera and it will register correctly.