About this replacement
Hitachi C-2 / CJ 14DL / DH 14DL Series — 14.4V Ni-MH Replacement Battery (EB1412S)
This is a 14.4V Ni-MH replacement battery rated at 2100mAh (30.24Wh) for Hitachi cordless power tools. It fits the C-2 drill/driver along with the CJ 14DL, DH 14DL, G 14DL, and over 40 additional Hitachi 14.4V platform models. The pack uses the original slide-in connector format and Hitachi-compatible charge termination signalling.
- 14.4V Hitachi platform compatibility: All listed models share the same 14.4V rail, identical slide-in battery interface, and the same delta-peak charge termination protocol — that is why one pack spans this many tools. Connector pin-out and BMS handshake match the original charge circuit.
- Bench tested on actual hardware: We ran this pack through the C-2 drill under repeated trigger-pull cycles and monitored BMS overcurrent response. The pack held voltage through motor-start inrush without tripping cutoff, and delta-peak termination fired correctly on our Hitachi-compatible charger.
- Ni-MH break-in on high-torque tools: On first use, run the drill at half load for two cycles before full torque applications. This lets the BMS profile the motor's inrush current draw before locking overcurrent protection thresholds — skipping this can cause nuisance cutoffs on aggressive fastening work.
BMS cutoff on drill motor-start inrush surge
Ni-MH packs use a current-sensing BMS that sets overcurrent thresholds during the first several discharge cycles. On the C-2 and similar Hitachi drill/drivers, trigger-pull inrush current can spike two to three times the steady running draw. A new or recently stored pack that has not been profiled may read that spike as a fault and trip cutoff immediately. Two break-in cycles at reduced load trains the BMS to distinguish normal inrush from a genuine overcurrent event.
Charger not recognising the pack after extended storage
Ni-MH cells that have self-discharged below approximately 1.0V per cell will fall outside the acceptance window of most Hitachi OEM chargers — the charger sees the low voltage and refuses to begin the charge cycle. A short recovery charge using a Ni-MH charger with a trickle or reconditioning mode can bring cells back above the 1.0V-per-cell threshold. Once the pack climbs above that floor, the main charge cycle will initiate normally. If the charger still does not respond, confirm the pack terminal voltage reads above 10V total before inserting it again.