Rokamat FOX 18V 6000mAh Replacement Battery

Rokamat FOX / DRAGONFLY / FILZER Series — 18V Li-ion Replacement Battery

This 18V 6000mAh (108Wh) Li-ion battery replaces the original pack on the Rokamat FOX, DRAGONFLY, FILZER, and WDVS-Sauger. The FOX is a professional concrete grinding and polishing machine used on floors and surfaces in construction and renovation work. Voltage and capacity match the OEM specification exactly.

• FOX, DRAGONFLY, FILZER, and WDVS-Sauger compatibility: These models share the same 18V battery platform, connector format, and BMS handshake protocol. Swapping packs across the range works because the voltage rail and communication lines are consistent across Rokamat's tool lineup.
• Bench tested on actual hardware: We ran this pack under simulated grinding load cycles and monitored the BMS response during motor-start inrush. Cell voltage stayed within the acceptable window and the BMS held without tripping overcurrent protection through repeated draw spikes.
• First-use load conditioning on the FOX: On the first two cycles, run the FOX at reduced disc pressure rather than full grinding load. This lets the BMS profile the motor's inrush current draw before locking overcurrent protection thresholds — preventing nuisance cutoffs on job sites.

BMS cutoff during FOX motor-start inrush surge

When the FOX motor spins up from a dead stop under disc load, inrush current spikes sharply before the motor reaches operating speed. A new pack with uncalibrated overcurrent thresholds can interpret this spike as a fault and cut the output immediately. This is a BMS protection trip, not a dead battery. Running two partial-load cycles first gives the BMS enough data points to distinguish a normal start surge from a genuine overcurrent event.

Pack drops out mid-grind under sustained heavy load

Sustained concrete grinding generates heat at both the motor and the battery cells simultaneously. When cell temperature climbs past the BMS thermal threshold — typically around 60°C — the pack cuts out to protect the cells. This is not a capacity failure. Let the pack cool for at least 10 minutes before resuming, and check that the battery slot in the tool housing is clear of dust buildup blocking airflow. Cell temperature should return below 40°C before restarting.