About this replacement
Aetep AT800 Series — 7.4V Li-ion Replacement Battery (BE-6398)
This 7.4V 5200mAh Li-ion pack replaces the OEM battery in Aetep AT800, AT810, AT820, and AT830 survey and measurement instruments. It matches the original voltage rail and connector configuration for those platforms. Capacity is sourced from product data at 5200mAh (38.48Wh) — not estimated.
- AT800 series platform fit: The AT800, AT810, AT820, and AT830 share the same battery bay geometry, 7.4V BMS handshake protocol, and connector pinout — which is why one pack covers all four. Swapping between models in this series requires no adapter or firmware change.
- Bench tested on actual hardware: We cycled this pack through sensor initialisation sequences on the AT800 platform. The BMS handled the current spike at probe power-up without triggering a cutoff, and held voltage stable across a sustained logging load.
- Calibration cycle before first field deployment: After installing this pack, run a full calibration cycle through the instrument menu before taking it into the field. The AT800 series maps battery state during calibration — skip this step and the instrument will report premature low-battery warnings during your first measurement session.
BMS lockout after the AT800 sat unused in a carry case for months
Li-ion cells in survey instruments self-discharge during storage. If the pack voltage drops below the BMS recovery threshold — typically around 2.5V per cell — the protection circuit locks out and the instrument will not power on or accept a charge. A standard charger sees this as a fault and refuses to begin a charge cycle. To recover, connect the pack to a charger that supports a low-voltage recovery or "boost" mode, which trickle-charges the cells back above 3.0V per cell before switching to normal CC/CV charging.
Voltage dropout causing readings to reset mid-logging session
Under sustained sensor load — particularly when multiple probe modules are active simultaneously — the battery voltage can sag momentarily below the instrument's minimum operating threshold. The AT800 interprets this as a low-power event and resets the active logging session to protect data integrity. This is not a firmware fault. Check that the battery rests above 7.2V under no-load before a long session; if it reads below that with a charged pack, the cells have degraded and the pack needs replacing.