About this replacement
GoPro Hero 4 Series — 3.8V Li-ion Replacement Battery (AHDBT-401)
This is a 3.8V Li-ion replacement cell rated at 1160mAh (4.41Wh) for the GoPro Hero 4, Hero 4 Silver, Hero 4 Black, and Hero 4+. It matches the OEM footprint at 36.20 × 32.63 × 10.84mm and slots directly into the battery compartment. Part number AHDBT-401 covers all four variants in this lineup.
- Hero 4 series compatibility: The Hero 4, Hero 4 Silver, Hero 4 Black, and Hero 4+ all use the same AHDBT-401 cell. They share the same voltage rail, physical connector, and battery compartment dimensions — one cell covers the full range without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Hero 4 Black body. The BMS accepted the cell without fault codes, and the protection circuit triggered correctly at the low-voltage cutoff threshold during deep discharge testing.
- First-use charge cycle on Hero 4: Insert the cell and charge it fully inside the camera body or via an OEM-compatible charger before your first shoot. The Hero 4 BMS maps the battery percentage indicator to the cell's discharge curve during this first cycle — skipping it can cause the indicator to read inaccurately from the start.
Why the Hero 4 battery indicator drops suddenly under 4K recording load
4K recording on the Hero 4 Black pulls significantly more current than 1080p — the image processor, sensor, and onboard stabilisation all draw simultaneously. This combined load causes a sharper voltage sag under peak demand. The camera's indicator interprets that voltage drop as a lower state of charge, so the display can jump several percentage points in seconds. This is normal behaviour under sustained high-resolution recording and is not a cell fault.
Hero 4 battery percentage jumping or reading 0% immediately after install
A new cell's discharge curve doesn't always align with the calibration map the Hero 4 BMS has stored from the previous battery. When that mismatch is large, the indicator reports erratic percentages or drops straight to zero. The fix is one full charge cycle inside the camera body — let it charge to 100% uninterrupted, then discharge through normal use. After that cycle, the BMS recalibrates to the new cell's curve and the percentage display stabilises. If it still reads 0% after a full cycle, check that the cell voltage is at least 3.6V before reinserting.