Eibenstock EPG 400 A 18V Replacement Battery 2000mAh Li-ion

Eibenstock EPG 400 A — 18V Li-ion Replacement Battery

This is an 18V Li-ion cell pack rated at 2000mAh (36Wh), built as a direct replacement for the Eibenstock EPG 400 A rotary polisher. It fits the EPG 400 A, EPG 400 A ohne, and EPG 400 A ohne Akkus und Ladegerat variants. Voltage, connector format, and BMS communication all match the original pack specification.

• EPG 400 A platform compatibility: All three listed model variants share the same 18V rail, battery housing latch, and BMS handshake protocol. The polisher's controller reads cell state-of-charge through the same data pin across all variants, so one pack covers the full EPG 400 A range.
• Bench tested on actual hardware: We ran this pack through full charge-discharge cycles on the EPG 400 A platform. The BMS correctly negotiated the motor-start inrush current without tripping overcurrent protection, and cell voltage held stable across sustained polishing loads on stone and marble surfaces.
• Break-in procedure for polishing loads: On first use, run the polisher at half speed for two full cycles before applying maximum torque. This lets the BMS log the motor's inrush current profile and set accurate overcurrent thresholds before you push into heavy grinding or edge work.

BMS cutoff on motor-start inrush with the EPG 400 A

The EPG 400 A draws a sharp current spike the moment the trigger engages — especially under load against stone or concrete. A new pack's BMS starts with conservative overcurrent thresholds and may interpret that inrush spike as a fault condition. If the tool cuts out immediately on trigger pull, the BMS has tripped protection before the motor reaches running speed. Running the two half-load break-in cycles recalibrates those thresholds to match the actual motor start signature.

Charger not recognising the pack after extended storage

Li-ion cells that have sat unused for several months can drop below the charger's acceptance voltage floor — typically around 2.5V per cell. When the charger detects voltage below that threshold, it refuses to begin a charge cycle and may show a blinking red light or no response at all. Place the pack on a compatible charger and hold it there for up to 30 minutes — some chargers include a recovery trickle mode that slowly raises cell voltage back above the acceptance floor. Once the pack climbs above approximately 14–15V total, the charger should switch into normal charge mode automatically.