Megalite P-335 Replacement Battery 7.2V 3600mAh Ni-MH

Megalite P-335 — 7.2V Ni-MH Replacement Battery (GP380AFH6YMXZ)

This is a 7.2V, 3600mAh Ni-MH replacement battery for the Megalite P-335 electronic distance measurement instrument. It slots directly into the P-335 and restores power to the device during surveying and construction fieldwork. Voltage and capacity match the original GP380AFH6YMXZ specification exactly.

• P-335 battery platform: The P-335 uses a 7.2V Ni-MH pack with a specific connector orientation and BMS handshake tied to the instrument's power management circuit. Any voltage deviation outside tolerance causes the instrument to flag a battery fault before powering the EDM module.
• Bench tested on actual hardware: We cycled this pack through charge and discharge under the P-335's typical measurement load. The BMS held the 7.2V nominal rail steady through repeated distance measurement sequences without tripping the low-voltage cutoff.
• First-use calibration cycle: After installing this battery, run a full calibration cycle through the P-335's instrument menu before heading into the field. The instrument maps battery state during calibration — skipping this step causes premature low-battery warnings on your first measurement session.

BMS lockout after the P-335 sat unused in a carry case for months

Ni-MH cells self-discharge slowly even in storage. After several months in a case, the pack voltage can drop below the BMS recovery threshold — typically around 5.5V on a 7.2V Ni-MH pack. When this happens, the instrument either refuses to power on or charges for a few minutes and then stops. The fix is a slow pre-charge at low current to bring the cells above recovery voltage before a full charge cycle begins. Most standard Ni-MH chargers handle this automatically — connect the pack and leave it for at least 30 minutes before checking charge status.

P-335 shuts down mid-measurement despite the battery showing charged

This usually comes from a brief voltage dropout when the EDM module fires a measurement pulse — the current spike at that moment briefly pulls the pack below the cutoff threshold. It is more common in older cells with elevated internal resistance, but it can also happen on a new pack that has not been conditioned yet. Run two full charge-discharge cycles before field use to stabilise internal resistance across the cell stack. If shutdown continues after conditioning, check that the battery contacts in the instrument bay are clean and making firm contact — a resistive connection amplifies voltage sag under load.