About this replacement
Metabo BS 9.6 Series — 9.6V Ni-MH Replacement Battery (6.25471)
This is a 9.6V, 3300mAh Ni-MH replacement battery for the Metabo BS 9.6 cordless drill-driver and its variants, including the BSP 9.6 and BSZ 9.6. It slots directly into the same battery bay and uses the same contact configuration as the original pack. Capacity is 3300mAh — matching or exceeding most worn original batteries still in circulation.
- BS 9.6 platform fit: The BS 9.6, BSP 9.6, and BSZ 9.6 all share the same 9.6V slide-in battery bay and connector pinout. This cell pack meets that voltage rail and mechanical spec across the full model range.
- Bench tested on actual hardware: We cycled this pack through repeated trigger-pull loads and monitored cell voltage under drill-driver torque demands. The BMS held stable across normal fastening and light drilling cycles without tripping overcurrent cutoff.
- Break-in procedure for Ni-MH packs: On first use, run the drill at half load — light fastening, no high-torque applications — for two full charge-discharge cycles. Ni-MH cells reach full capacity after conditioning; skipping this can leave up to 15% of rated capacity untapped in early cycles.
BMS cutoff on motor-start inrush in the BS 9.6
When you pull the trigger on a drill-driver, the motor draws a brief current spike — often three to five times the running current — before reaching operating speed. On a new or recently stored Ni-MH pack, the BMS overcurrent threshold may not yet be profiled to the motor's inrush signature. This can cause the pack to cut out on the first hard trigger pull. Running two break-in cycles at reduced load lets the BMS log normal inrush values before you apply full torque. After conditioning, abrupt cutoffs on trigger pull typically stop.
Drill bogs under load and feels weaker than expected
If the BS 9.6 spins freely but loses torque when the bit bites into material, the most likely cause is voltage sag — cell voltage dropping under load due to elevated internal resistance. On Ni-MH packs, this worsens with age or after extended storage. Check the battery contact rails on both the tool and pack for corrosion or debris; even light oxidation adds resistance and amplifies sag. Clean contacts with isopropyl alcohol, then check pack voltage under load — a healthy 9.6V Ni-MH pack should hold above 8.5V during moderate drilling.