About this replacement
Panasonic EZ571 / EY6282EQK Series — 9.6V Ni-MH Replacement Battery (EY9180B)
This is a 9.6V, 2100mAh Ni-MH replacement battery for the Panasonic EZ571 cordless drill/driver and related models including the EY6282EQK, EYN595, and EY9184. It replaces OEM part numbers EY9180B and EY9180. Slot it in where the original pack failed — same voltage rail, same physical footprint.
- EZ571 and EY6282EQK platform fit: These models share the same 9.6V pack housing, contact layout, and thermal cutoff signalling. One battery covers the full group without adapter modifications or rewiring.
- Bench tested on actual hardware: We cycled this pack through repeated load pulls on the EZ571 platform. The thermal cutoff tripped correctly under sustained stall conditions and reset cleanly after a two-minute cooldown — no latched fault states.
- Ni-MH break-in on the EZ571: Run the first two cycles at light to medium load before pushing full torque. Ni-MH cells reach stable capacity after a few charge-discharge cycles — skipping this step can leave the pack performing below its rated 2100mAh in early use.
Voltage sag on the EZ571 under sustained drilling load
Ni-MH cells have higher internal resistance than Li-ion, so the 9.6V rail drops noticeably when the motor draws continuous current through dense material. On the EZ571, this shows up as the chuck slowing mid-hole rather than maintaining speed. Dirty or corroded pack contacts amplify the sag — resistance at the contact points compounds the cell's own internal resistance drop. Clean the contacts on both the pack and the tool's battery bay with a dry cloth before assuming the cells are at fault.
Charger not recognising this pack after extended storage
Ni-MH packs that sit unused for several months self-discharge below the voltage threshold some Panasonic chargers require to start a charge cycle. If the charger shows no activity or flashes an error immediately, the cells may have dropped below 1.0V per cell. A short manual trickle at around 100mA for 15–20 minutes using a compatible NiMH recovery charger can bring the pack voltage back above the acceptance threshold. Once the pack reaches roughly 9V total, re-insert it into the standard charger and it should begin a normal charge cycle.