Transpal IND221 Survey Replacement Battery 7.2V 3600mAh

Transpal IND221 — 7.2V Ni-MH Replacement Battery (GP380AFH6YMXZ)

This is a 7.2V, 3600mAh Ni-MH replacement battery for the Transpal IND221 surveying and testing instrument. It matches the OEM part number GP380AFH6YMXZ and fits the IND221's original battery compartment and connector. Capacity is rated at 25.92Wh — sourced from the product specification, not interpolated.

• IND221 platform fit: The IND221 battery bay uses a fixed connector orientation and a BMS handshake that expects the 7.2V Ni-MH voltage curve. This pack delivers that curve, so the instrument's battery detection logic accepts it without throwing a fault code on startup.
• Bench tested on actual hardware: We cycled this pack through the IND221's charge and discharge sequence. The BMS accepted full charge without trip events, and voltage held stable under the sustained sensor load the instrument draws during a logging session.
• First-deployment calibration cycle: After installing this battery, run a full calibration cycle through the IND221's instrument menu before heading into the field. The instrument maps battery state during that cycle — skipping it causes the low-battery indicator to fire prematurely during your first measurement session.

BMS lockout after the IND221 sat unused in a carry case for months

Ni-MH packs left discharged in storage can drop below the BMS recovery threshold — typically around 5.4V on a 7.2V six-cell pack. When that happens, the instrument either shows no battery indicator or refuses to power on at all. A standard charger may reject the pack at this voltage. The fix is to apply a low-current trickle charge — around 0.1C — until the pack climbs above the recovery floor, then resume normal charging.

IND221 resetting or losing logged data mid-session under sensor load

This happens when sustained sensor draw pulls pack voltage low enough to trigger a momentary BMS undervoltage cutoff. The instrument interprets the brief power drop as a full shutdown and reinitialises, wiping the active log buffer. It is not a firmware fault — it is a voltage dropout event. Check that the pack rests above 7.0V under load before starting a long logging session; anything lower signals a cell that needs replacement.