E-Mopeds
E-Moped Battery Won't Hold a Charge Over Winter
After storage in winter, the battery charges but drains quickly or won't charge at all.
What causes it
Lithium batteries discharge while stored, and deep discharge below the BMS cutoff permanently damages cells.
What to do
- Charge to ~60-80% before storing - never store fully charged or fully empty.
- Recharge every 4-6 weeks during storage to prevent deep discharge.
- Store in a cool, dry place - ideally 10-20°C, not freezing and not hot.
- If it won't charge after storage, try a slow trickle charge to wake the BMS.
- If the pack was below 0V, the cells may be damaged and the battery needs replacement.
Prevention
The most common winter EV failure is a dead battery from sitting empty. A monthly top-up charge takes two minutes and saves a $300-800 battery.