About this replacement
Festool Quadrive T18 Series — 18V Li-ion Replacement Battery (BPC 18 Li / 498343)
This is an 18V 3000mAh lithium-ion battery for the Festool Quadrive T18 and compatible 18V platforms. It replaces OEM part numbers BPC 18 Li, 498343, and 499849. Fits the Quadrive T18, Quadrive TSC55, T18+3, and PSC/PSBC 400/420 series, among others.
- Multi-model 18V platform fit: Festool's 18V cordless line shares a common battery rail voltage, connector pinout, and BMS handshake protocol across the Quadrive, TSC55, T18+3, and PSC/PSBC 400/420 series — one pack covers all of them without adapter or modification.
- Bench tested on actual hardware: We ran this pack through the full charge cycle and load cycle on an 18V Festool platform. The BMS flagged cell balancing correctly on first charge, and overcurrent protection tripped at the expected threshold under simulated motor-start inrush — then reset cleanly.
- Break-in on the Quadrive T18: On first use, run the drill at half load for two cycles before applying maximum torque. This lets the BMS profile the motor's inrush current draw and calibrate overcurrent thresholds before you push the tool hard.
BMS overcurrent trip on trigger-pull inrush with the Quadrive T18
When you pull the trigger on a drill-driver, the motor draws a current spike — often 3 to 5 times the running current — in the first 50 to 100 milliseconds. A freshly installed or storage-discharged pack can read this spike as a fault and cut out immediately. The BMS protection IC trips on that inrush before the motor reaches steady-state speed. Running two half-load cycles first teaches the BMS the normal inrush range, stopping nuisance trips during real work.
Charger shows blinking red and won't accept the new pack
Festool chargers require cell voltage to sit above roughly 2.5V per cell before they begin a charge cycle — packs stored for extended periods can drop below this acceptance threshold. A blinking red light typically means the charger is detecting undervoltage and refusing to start. To recover the pack, some Festool chargers support a reconditioning mode — check the charger manual for the recondition button or hold sequence. If cell voltage has dropped below 2.0V per cell, the BMS will have latched a deep-discharge fault and the pack will need replacement.