About this replacement
GoPro Hero 5 / Hero 6 — 3.85V Li-ion Replacement Battery (AHDBT-501)
This is a 3.85V, 1250mAh Li-ion replacement cell for the GoPro Hero 5 and Hero 6 action cameras. It fits the compact battery bay on CHDHX-501 and ASST1 bodies, along with ten additional Hero-series models. Dimensions are 35.80 × 31.20 × 11.30mm — same footprint as the OEM AHDBT-501.
- Hero 5 and Hero 6 platform fit: Both cameras share the same battery bay dimensions, connector pinout, and BMS communication protocol. One cell covers both bodies without modification.
- Bench tested on actual hardware: We ran this cell through the Hero 5 body. The BMS accepted the cell, voltage at full charge read 4.35V, and the camera reported battery level correctly through a full discharge cycle.
- First-install charge cycle on Hero 5: Insert the new cell and charge it directly inside the camera body before your first shoot. The Hero 5 BMS maps its battery-remaining display against a full internal charge cycle — skipping this step can cause the indicator to read inaccurately until one complete cycle is completed in-body.
Why the Hero 5 battery percentage jumps erratically with a new cell
The Hero 5 uses a voltage-threshold model to estimate remaining capacity. A new cell has a slightly different discharge curve shape than an aged OEM cell, so the camera's thresholds don't align correctly on the first cycle. The indicator may jump from 80% to 40% without warning, or hold at 100% longer than expected. After one or two full charge-and-discharge cycles completed inside the camera body, the display stabilises.
Hero 5 showing dead battery icon on a cell you know has charge
This happens when the cell voltage drops below the camera's minimum wake threshold — typically around 3.0V — usually from storage in a discharged state. The BMS locks out the cell as a protection measure and the body won't power on. Place the cell in an external USB charger set to Li-ion 3.85V mode for 15–20 minutes to recover it to at least 3.2V, then reinsert it into the camera body to resume normal charging.