Rokamat FOX 18V Li-ion Replacement Battery 3000mAh

Rokamat FOX / DRAGONFLY / FILZER Series — 18V Li-ion 3000mAh Replacement Battery

This is an 18V Li-ion battery rated at 3000mAh (54Wh), built to fit the Rokamat FOX, DRAGONFLY, FILZER, and WDVS-Sauger cordless tools. It slots into the same battery bay as the original pack and communicates with the same BMS handshake those platforms expect. Voltage and connector match the OEM specification.

• FOX and DRAGONFLY platform fit: These Rokamat tools share the same 18V battery rail, connector pinout, and BMS communication protocol — which is why one pack covers the full range. Swapping between models on a single spare battery is straightforward.
• Bench tested on actual hardware: We cycled this pack through repeated trigger-pull inrush events on a FOX unit. The BMS held through motor-start current spikes without nuisance tripping and maintained a stable voltage rail under sustained load.
• Break-in cycle on the FOX: On first use, run the FOX 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 cutoff on FOX motor-start inrush surge

When you pull the trigger on the FOX, the motor draws a short inrush current spike that can be several times the steady-state draw. A new pack from storage — or a cold pack below 5°C — has higher internal cell resistance, which makes that voltage dip steeper and more likely to trip the BMS overcurrent threshold. The BMS interprets this as a fault and cuts the output to protect the cells. Warming the pack to room temperature before use and running two light-load break-in cycles brings internal resistance down and raises the trip margin.

Charger shows blinking red and never accepts a new pack

If the Rokamat charger blinks red continuously on a new or stored pack, the cell voltage has likely dropped below the charger's acceptance threshold — typically around 2.5V per cell for an 18V Li-ion pack in a depleted state. Most chargers refuse to charge below this point as a safety measure, but the pack is not dead. Connect the pack to the charger and leave it for 10–15 minutes — some chargers include a recovery mode that trickle-charges at low current to bring the cells back above the threshold. If the charger moves from blinking red to steady red or green, the recovery is working. If it stays blinking after 20 minutes, check cell voltage directly — anything below 14V total across the pack indicates a cell that needs replacement.