Why is my inverter not charging the battery?
If your battery percentage isn't going up, the inverter is usually telling you why – a setting, the weather, the grid, or a protection that has kicked in.
The most common reasons
Most charging problems come down to a few causes. Some you can check from your phone; others need an installer.
- Not enough sun – cloudy days, winter or dusty panels.
- Charging settings in the app (for example grid charging switched off or time-of-use windows).
- Heavy loads using all the solar before it reaches the battery.
- The battery management system (BMS) has stopped charging to protect the battery.
- A fault code on the inverter, such as a BMS communication fault.
What you can safely check
Stick to these checks – never touch the battery or its connections.
- Go to the inverter app and look at solar input, load and battery power at the same time.
- Check the charge settings and time-of-use windows in the app.
- Switch off heavy appliances for an hour and see if charging starts.
- Check for load-shedding or a municipal outage if you rely on grid charging.
- Rinse dusty panels with a garden hose while standing on the ground.
When to call a pro
Call a qualified installer if the battery shows a BMS or communication fault, gets hot, swells, smells, or won't charge even on a sunny day with low loads. Don't change battery protection settings yourself.
Solar systems carry dangerous voltages. Only do the safe checks listed. If unsure, call a pro.
Common questions
- Can I reset the battery myself?
- No. Battery protection settings and connections should only be handled by a qualified installer. You can restart the inverter using its documented procedure.
- Why does my battery charge slowly in winter?
- Shorter days and a lower sun mean less solar energy, so less is left over for the battery after your home's loads.