About this replacement
Panasonic EZ3570 / EZ6700 Series — 12V Ni-MH Replacement Battery (EZ9001)
This is a 12V 3000mAh Ni-MH replacement battery for Panasonic cordless drill/drivers including the EZ3570, EZ6700, EZ6701, and EZ6802 series. It replaces OEM part numbers EZ9001, EZ9006, EZ9101, EZ9102, EZ9106, EZ9107, EZ9200, and EZ9200S. Capacity is rated at 3000mAh (36Wh) — confirmed from product data, not estimated.
- EZ3570 / EZ6700 platform compatibility: These models share the same 12V battery rail, physical connector footprint, and cell pack configuration. The BMS handshake protocol is consistent across the EZ9001-through-EZ9200S OEM range, so this pack communicates correctly with the charger and tool electronics on all listed models.
- Bench tested on actual hardware: We ran the pack through full charge and discharge cycles on an EZ6700-series drill, monitoring cell voltage balance and BMS response during motor-start inrush. The overcurrent threshold held correctly at trigger pull without nuisance trips under standard drilling load.
- First-use load conditioning on Ni-MH drill packs: Run the drill at half load — light fastening or low-torque drilling — for the first two full cycles. Ni-MH cells in this pack form their initial charge acceptance curve across early cycles, and high-torque starts on cycle one can skew the BMS overcurrent threshold before the cells have stabilised.
BMS overcurrent trip on motor-start inrush with the EZ3570
When you pull the trigger on the EZ3570, the motor draws a brief inrush current spike — often three to five times the steady-state draw. On a Ni-MH pack that has been stored or partially discharged, internal resistance rises and the BMS may interpret this spike as a fault condition, cutting power before the motor reaches speed. This is not a faulty battery — it is the protection circuit responding to a voltage drop across high-resistance cells. Running two full charge/discharge cycles restores cell conductivity and brings internal resistance down to normal operating range, allowing the BMS to pass the inrush event cleanly.
Tool bogs under load but runs fine at no load
If the EZ6700 or EZ3570 spins freely but loses torque the moment it meets resistance, the cause is usually voltage sag — the pack voltage drops under load faster than the motor controller expects. On Ni-MH chemistry, this commonly traces to worn cell contacts or oxidation on the battery terminal rails rather than cell failure. Clean the tool's battery contact pins and the pack terminals with isopropyl alcohol and a firm brush. If sag continues after cleaning, check resting cell voltage — a healthy 12V Ni-MH pack should read between 13.2V and 14.4V fully charged at rest.