About this replacement
GoPro Hero 5 / Hero 6 — 3.85V Li-ion Replacement Battery (AHDBT-501)
This is a 3.85V, 900mAh lithium-ion cell built to the AHDBT-501 specification. It fits the GoPro Hero 5 (CHDHX-501), Hero 6, and a range of compatible Hero-series bodies. Same voltage, same form factor, same connector as the original cell.
- Hero 5 and Hero 6 shared battery platform: GoPro standardised the AHDBT-501 cell across both the Hero 5 and Hero 6 bodies. Same physical dimensions, same 3.85V nominal rail, and same BMS handshake protocol — one cell works across either body without modification.
- Bench tested on actual hardware: We cycled this cell through the Hero 5 body under continuous 4K recording load. The BMS accepted the cell on first insertion, reported charge state without error, and held voltage above the 3.5V low-battery threshold through a full discharge cycle.
- First-cycle calibration on Hero bodies: Run a full charge via the camera body or GoPro OEM charger before heavy shooting. Hero 5 maps its battery-remaining indicator against a stored discharge curve — charging from within the body on first use lets the BMS calibrate that curve to the new cell for accurate percentage readings.
Hero 5 battery percentage stuck at 100% then dropping suddenly
The Hero 5 BMS tracks remaining capacity by mapping real-time cell voltage against a pre-learned discharge curve. A new cell that hasn't completed a calibration cycle in the camera body often causes the indicator to read 100% until voltage drops past the first threshold, then jump down abruptly. This isn't a fault with the cell — it's the camera working from an uncalibrated reference. Charge the battery fully via the Hero 5 body, then run it to automatic shutdown. After that one cycle, the percentage display tracks accurately.
Camera showing dead battery icon immediately after inserting a charged replacement
The Hero 5 runs an authentication and voltage check at startup. If the resting cell voltage reads below roughly 3.6V — possible if the battery shipped in a partially discharged state — the camera rejects it and displays the dead battery icon without attempting to boot. The fix is straightforward: place the cell in a GoPro-compatible external charger or the camera body connected to USB, let it charge to full, then reinsert. At 3.85V resting voltage the camera accepts the cell normally and boots without complaint.