Atlas Copco LokTor H18 18V Replacement Battery 4000mAh

Atlas Copco LokTor H18 / P18T / S18P Series — 18V Li-ion Replacement Battery

This 18V 4000mAh (72Wh) Li-ion battery fits the Atlas Copco LokTor H18, P18T, P18TX, S18P, and eight additional LokTor variants. The LokTor line is a precision cordless torque wrench platform used in controlled-torque assembly and manufacturing. This pack slots in where the original battery has degraded or where a spare is needed to keep production moving.

• LokTor platform compatibility: The H18, P18T, P18TX, and S18P share the same 18V battery rail, connector footprint, and BMS communication protocol — that is why a single pack covers the full series. Swapping between LokTor variants on the same line does not require a different battery.
• Bench tested on actual hardware: We cycled this pack through repeated torque-wrench load profiles, including motor-start inrush spikes. The BMS held without nuisance trips and recovered voltage cleanly between fastening sequences.
• Motor inrush conditioning on first use: Run the tool at half-load torque settings for two cycles before moving to maximum torque applications. This lets the BMS profile the motor inrush current draw and set overcurrent protection thresholds accurately before full fastening loads are applied.

BMS cutoff on LokTor motor-start inrush surge

Precision torque wrenches draw a sharp current spike the instant the motor starts — this inrush can hit three to five times the steady-state draw in milliseconds. If the BMS has not yet mapped the motor's inrush signature, it may read that spike as an overcurrent fault and cut power immediately. A new or freshly stored pack is most vulnerable because its BMS threshold is uncalibrated to the specific motor load. Two half-load conditioning cycles give the BMS enough data to distinguish normal start inrush from a genuine fault current.

Tool bogs or loses torque accuracy mid-sequence

If the LokTor loses torque force partway through a fastening sequence, the cause is almost always voltage sag — the cell voltage drops under load faster than the tool's control circuit expects. On a precision torque wrench, that translates directly to inaccurate fastening results, not just a sluggish feel. Check the battery rail contacts for oxidation or debris first, as high contact resistance amplifies sag significantly. If contacts are clean, the pack may have capacity fade from shallow cycling — run a full discharge and recharge cycle and retest with a torque checker.