About this replacement
Panasonic EZ6225 Series — 3.6V Ni-MH Replacement Battery (EZ9025)
This is a 3.6V, 3300mAh Ni-MH replacement battery for the Panasonic EZ6225 cordless drill/driver and compatible models including the EZ6225C15, EZ622X, and EY6225. It fits the original battery slot using the same connector and terminal layout as the OEM pack. Voltage and capacity match the factory specification exactly.
- EZ6225 series compatibility: The EZ6225, EZ6225C15, EZ622X, and EY6225 all share the same 3.6V battery platform — same connector housing, same terminal pitch, same BMS communication protocol. A single cell configuration covers all variants in this family.
- Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on the EZ6225 platform. The BMS accepted the pack without fault codes, held voltage through trigger-pull inrush, and the charger completed the cycle without interruption.
- Break-in on Ni-MH packs: Run two full discharge-and-recharge cycles before putting this pack under sustained load. Ni-MH cells need conditioning to reach rated capacity — the first charge off the shelf will read lower, and that is normal for this chemistry.
BMS cutoff on the EZ6225 during motor-start inrush
The EZ6225 draws a short inrush spike the moment the trigger closes — this is the motor overcoming static friction before it starts spinning. On a new or cold Ni-MH pack, the BMS may read this spike as an overcurrent event and trip before the motor reaches speed. The protection threshold is set conservatively on 3.6V single-cell packs because there is no cell buffer. Running two break-in cycles lets the BMS log the motor's inrush signature and stop treating it as a fault condition.
Drill bogs under load but charger shows full
If the tool feels weak during driving or stalls on fasteners while the charge indicator reads full, the fault is usually voltage sag at the terminal contacts, not low capacity. Ni-MH cells sag harder than lithium under sustained load, and corroded or loose rail contacts make this worse. Clean the battery terminals and the tool's contact rails with isopropyl alcohol, then check the resting voltage after a full charge — it should read at or above 4.2V before any load is applied.