Makita 678102-6 4.8V Cordless Drill Replacement Battery 1500mAh

Makita 6041D Series — 4.8V Ni-MH Replacement Battery (678102-6)

This is a 4.8V, 1500mAh Ni-MH replacement battery for the Makita 6041D, 6041DW, 6043D, and 6043DWK cordless drill/drivers. It slots into the same battery bay as the original 678102-6 pack, restoring power to a tool that still has years of mechanical life left. Capacity is 1500mAh — matched to the original specification.

• 6041D and 6043D platform fitment: These models share the same 4.8V battery bay geometry and connector pinout. The BMS on each communicates over the same signal line, so one pack covers the full platform without adapter or modification.
• Bench tested on actual hardware: We cycled this pack through charge and load on a 6041D chassis. The BMS accepted charge from the standard Makita DC9700 charger, held voltage across sustained trigger pulls, and showed no premature cutoff during torque-load testing.
• Ni-MH storage between jobs: If this tool sits unused for more than a month, store the pack at a partial charge — roughly 40–60% — not fully charged. Ni-MH cells held at full charge for extended periods accelerate internal self-discharge and degrade cycle capacity faster than partial-state storage.

BMS overcurrent trip on trigger-pull inrush in the 6041D

The 6041D motor draws a sharp current spike in the first milliseconds of trigger engagement — the inrush current as the armature begins spinning. On a degraded or cold pack, this spike can exceed the BMS overcurrent threshold, causing an immediate cutoff that looks like a dead battery. The cell's internal resistance rises when cells are cold or aged, amplifying the voltage sag during that inrush window. A new pack with fresh cells has lower internal resistance and handles the spike without tripping the protection circuit.

Charger not recognising the new pack after storage

Ni-MH packs that have been stored discharged can drop below the charger's minimum acceptance voltage — typically around 1.0V per cell. The DC9700 and similar Makita chargers will not begin a standard charge cycle on a pack reading below that threshold. Most chargers have a trickle-recovery mode that slowly brings the pack up to acceptance voltage before switching to full charge — check your charger manual for an indicator that confirms this mode is active. If the charger shows no activity at all after five minutes, remove the pack, leave it at room temperature for 30 minutes, then reinsert — pack voltage sometimes recovers slightly once thermal equilibrium is reached.