About this replacement
PowerPlus POWXG6310 — 18V Li-ion Replacement Battery (103.139.06)
This is an 18V 5000mAh Li-ion replacement battery for the PowerPlus POWXG6310 cordless lawn mower. It matches the OEM part number 103.139.06 and fits the POWXG6310's original battery slot and connector. Capacity is rated at 90Wh.
- POWXG6310 platform fit: The POWXG6310 uses an 18V battery rail with a specific connector keyed to this form factor. The BMS in this pack communicates with the mower's motor controller to manage discharge rate under blade load — if the voltage signature doesn't match, the mower won't arm. This pack replicates that handshake.
- Bench tested on actual hardware: We ran this pack through full charge-discharge cycles on a load bench simulating blade motor inrush current. The BMS held steady through repeated high-draw pulses and did not trip during the motor-start surge that causes most aftermarket packs to cut out.
- Cold-weather start tip: Before the first mow of the season, bring the battery indoors overnight if temperatures are below 10°C. Cold Li-ion cells have higher internal resistance, and the blade motor's inrush current can trip the BMS on a cold pack before the mower takes a single pass.
BMS cutoff during thick-grass or wet-grass cutting
The POWXG6310 blade motor draws significantly more current when the grass is dense, wet, or long. This inrush can spike well beyond the steady-state draw the BMS is calibrated for during normal conditions. If the pack detects a current spike that exceeds its protection threshold, it will cut power instantly to protect the cells. Let the mower sit for 30 seconds after a cutout, then restart — if it happens repeatedly, reduce cutting speed through the row or raise the cutting height.
Charger shows fault light after the mower sat unused all winter
Li-ion cells self-discharge slowly over months of storage. If the POWXG6310 battery sat in a cold garage all winter, cell voltage may have dropped below the charger's acceptance threshold — typically around 2.5V per cell. A charger seeing a pack below that threshold will flag a fault and refuse to charge as a safety measure. To recover the pack, check whether your charger has a recovery or wake-up mode; some chargers will trickle charge at a low rate to bring cells back above the acceptance floor before switching to normal charge.