About this replacement
Supremo 4K Plus — 3.7V Li-ion Replacement Battery (SP523450P)
This 3.7V 1000mAh Li-ion cell replaces the original battery in the Supremo 4K Plus action camera. It matches the OEM part number SP523450P and fits the camera's compact battery bay without modification. Voltage and physical dimensions are identical to the factory cell: 45.40 × 36.50 × 8.90mm.
- 4K Plus platform fit: The Supremo 4K Plus runs a single-cell 3.7V rail. The camera's BMS expects a cell within a narrow voltage window at startup — this replacement matches that window, so the camera accepts it without triggering a low-voltage lockout on first boot.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a cell analyser. The BMS protection board tripped correctly at the low-voltage cutoff and accepted a full charge to 4.2V with no anomalies in charge termination behaviour.
- First charge cycle on the 4K Plus: Run the first full charge inside the camera body or OEM charger before shooting. Some action camera BMS systems map the battery-remaining display to the new cell's discharge curve only after one complete in-device charge cycle — skipping this step can cause the indicator to read inaccurately from the start.
Camera showing dead battery indicator on a partially charged replacement cell
The Supremo 4K Plus reads cell state-of-charge by mapping terminal voltage to a stored lookup table. A new cell that hasn't completed one full charge cycle inside the camera can sit at a resting voltage the BMS interprets as depleted — even when the cell is holding 50% or more charge. This is not a cell fault. Insert the battery, connect the camera to its charger, and let it charge to 100% without interruption. After that first complete cycle, the indicator syncs to the correct discharge curve.
Battery percentage jumping erratically during 4K recording
Sustained 4K recording pulls sensor, processor, and codec current simultaneously — draw spikes cause the terminal voltage to sag momentarily below the threshold the indicator uses for each percentage step. The camera reads that sag as a sudden capacity drop and updates the display accordingly. This is a voltage-sag artefact, not cell failure. If the percentage stabilises when you drop to 1080p or stop recording, the cell is behaving normally — the 4K power draw is simply exceeding what the indicator was calibrated to handle smoothly.