What you will see
- Backup stopped late at night during long load-shedding
- Battery will not discharge even after grid returns
- App shows the battery charging from grid first
Why it happens
Lithium batteries are damaged by deep discharge, so the inverter keeps a reserve and charges back above it before allowing discharge again.
Battery current can also be limited by temperature, so backup may end earlier on very hot or cold days.
Diagram
How a long outage ends
- 01Load-shedding starts
- 02Battery powers backup
- 03Battery reaches its minimum
- 04Backup stops
- 05Grid returns, battery recharges first
This protects the battery. It is not a fault.
What you can check yourself
- Check the battery percentage history in iSolarCloud
- Reduce backup loads during long outages
- Let the battery recharge fully; Sungrow recommends a full charge at least every couple of weeks if it is rarely filled
What not to do
- Do not force discharge or change battery settings yourself
When to call us
- Review backup loads against battery size
- Check minimum SOC and charge settings
- Advise on adding battery capacity if needed
Long outages
Long load-shedding hours in parts of Punjab drain batteries faster than expected. We size backup loads and batteries for homes in Faisalabad and Lahore.
Send us
battery history screenshots and a list of loads on backup