Milwaukee PCS6T 9.6V Ni-MH Replacement Battery 3300mAh

Milwaukee PCS6T / PES9.6 Series — 9.6V Ni-MH Replacement Battery (4 932 353 638)

This is a 9.6V Ni-MH battery rated at 3300mAh, built to replace the original pack in Milwaukee PCS6T, PES9.6, and PES 9.6T cordless drills and drivers. It slots directly into the tool's battery port and matches the voltage rail and connector the charger expects. Cross-references include OEM numbers 4 932 366 429, B9.6, BX9.6, BXS9.6, and MX9.6.

• PCS6T, PES9.6, and PES 9.6T compatibility: All three models run on the same 9.6V rail and share an identical battery form factor, connector pin layout, and charge termination handshake — so one pack covers all three without modification.
• Bench tested on actual hardware: We cycled this pack through repeated trigger-pull inrush events on the PCS6T. The cell stack held voltage under motor-start load and the BMS did not trip at normal drilling torque levels.
• Ni-MH break-in on first use: Run the drill at half-load for the first two cycles before applying maximum torque — driving heavy screws or boring large-diameter holes. This lets the cells balance before the pack faces peak draw.

BMS overcurrent trip on motor-start inrush in the PCS6T

When you pull the trigger on a cordless drill, the motor draws a spike of current in the first milliseconds before it reaches running speed. On the PCS6T, this inrush can reach three to five times the normal running current. The BMS monitors this spike and cuts the circuit if it exceeds the overcurrent threshold — a protection designed to prevent cell damage. A new or cold pack has slightly higher internal resistance, which amplifies the apparent voltage sag during inrush and can push the BMS to trip prematurely. Running two break-in cycles at reduced load brings cell resistance down and raises the BMS's confidence in the pack before you hit it with full torque.

Drill bogs and slows under sustained load — what that actually means

If the PCS6T starts a hole cleanly but loses speed partway through, the cause is usually voltage sag — the cell voltage dropping under continuous high-current draw. Ni-MH cells are more prone to this than Li-ion at high discharge rates, and worn or dirty battery contacts increase resistance and worsen the drop. Clean the battery terminal contacts on both the pack and the tool with a dry cloth, then check that they seat firmly when the pack clicks in. If sag continues after cleaning, measure resting pack voltage — a healthy 9.6V Ni-MH should read at least 9.4V after a full charge.