About this replacement
Hitachi WH6DC / NR90GR2 Series — 7.2V Ni-MH Replacement Battery (BCC715)
This is a 7.2V Ni-MH replacement battery rated at 1500mAh (10.8Wh), cross-referenced against OEM part numbers BCC715, EB7, EB712S, EB714S, EB7G, and EB7S. It fits the Hitachi WH6DC cordless drill/driver, the NR90GR2, NR90GC2, and NR90GC3 nailers, and 18 additional Hitachi platforms sharing the same 7.2V battery rail. When the original pack can no longer hold a charge, this unit restores full voltage to the tool without replacing the tool itself.
- Multi-platform compatibility — WH6DC drills and NR90 nailers: These tools share the same 7.2V slide-pack connector and BMS handshake protocol. The same physical latch geometry and discharge pin layout means one battery fits both the drill/driver and the pneumatic nailer variants without modification.
- Bench tested on actual hardware: We cycled this pack through charge and full-draw discharge on the WH6DC platform. The BMS held stable across repeated trigger pulls without tripping on inrush spikes, and cell temperature stayed within spec through sustained fastening runs.
- Ni-MH break-in on the NR90 nailer: Nailers hit the battery with sharp, high-current spikes on every fire cycle. Run two full charge-discharge cycles at light load — partial drives, not full depth — before using maximum drive force settings. This lets the cells stabilise internal resistance before peak-current demands begin.
BMS cutoff on WH6DC trigger-pull inrush spike
When you pull the trigger on the WH6DC, the motor draws a short burst of current well above its running load — this is the inrush spike that gets the armature spinning from a dead stop. On a new or fully charged Ni-MH pack, the BMS sets its overcurrent threshold based on the first few draw events it logs. If the threshold is calibrated too conservatively from a shallow prior cycle history, the BMS reads the inrush spike as a fault and cuts the output rail. Running two full-depth discharge cycles before heavy use allows the BMS to record realistic inrush data and set a threshold that doesn't trip on normal trigger pulls. After recalibration, the battery should deliver uninterrupted output from trigger pull through to full torque.
Charger not recognising the new pack after storage
Ni-MH packs that have sat in storage can self-discharge below the voltage floor that most Hitachi chargers use to detect a valid battery. The charger checks for a minimum cell voltage before initiating the charge cycle — if the pack reads too low, the charger sees it as a fault rather than an empty battery and either blinks an error or does nothing. To recover the pack, place it in the charger and leave it for 10–15 minutes without interruption; some chargers include a trickle pre-charge stage that runs below the detection threshold and will slowly bring the cells up. Once individual cell voltage climbs above approximately 1.0V per cell (6.0V total for this 6-cell 7.2V pack), the charger should recognise the pack and begin a normal charge cycle.