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My battery is at 0% or very low. What should I do?

Short answer. Check the app for an alarm, then see whether solar or the grid is charging it. A battery left empty for a long time can be damaged: Sigenergy says to charge it within 30 days if it is at 10% or more, and within 7 days if it is below 10%. If it is not charging, call us the same day.

A low battery after a heavy evening, a cloudy week or a blackout is normal. What matters is whether it is recovering when the sun comes up.

Safety first. Do not try to charge or reset the battery yourself. Never open a switchboard, remove a cover from your battery or inverter, or touch any wiring. Anything beyond the app, a light you can read from a safe distance, or your own router is a job for a licensed electrician. If you see smoke, smell burning, hear arcing or see water on or near the unit: keep everyone away, switch off at your main switch only if it is safe to do so, and call 000 if there is any fire or smoke.

What to check

  1. Open the app and look at the battery percentage and the direction of the arrow: is it charging, or sitting still?
  2. Look for an alarm in the app (mySigen: Home, then Notice, or Service. SEMS+: Alarm on the home page). Take a screenshot.
  3. Is solar producing? If it is a cloudy week, give it a sunny day. If solar is producing and the battery is still not charging, tell us.
  4. Was there a blackout? Sigenergy’s Backup Reserve holds energy back for blackouts, and GoodWe stops supplying the home at its off-grid lower limit and recharges from solar before supplying power again. It may just be recharging.
  5. Is the system offline? An offline system keeps running, but we cannot see it: see our Wi-Fi guides.
  6. If it has not recovered in a day or so of reasonable sun, call us with your screenshot.

What the manuals say

  • Sigenergy: self-discharge causes power loss, and a battery not charged for a long time may be damaged by over-discharge. If it cannot charge, contact your installer in time.
  • Sigenergy lists scenarios that may cause a charge failure, including no solar input and the grid being off for a long time.
  • GoodWe: if the battery is not used for a long time or is not fully charged, it recommends charging it regularly.

If your system is going to be switched off for a long time, for example for building work, call us first.

Read more: Sigenergy batteries and GoodWe batteries from Sun Connect Solar

When to call us

If we installed your system, call us on 0483 903 020. Our service help for existing customers is free: we start by working through it with you by phone. If you are not yet a customer, a service call is $250 + GST, which covers one hour on site within 20 km of Mullumbimby; travel further out is quoted separately. Contact us or call 0483 903 020 (Mon-Fri 7am-6pm, Sat 7am-4pm).

Quick questions

How long can it stay at zero?

Sigenergy says to charge it within 7 days if it is below 10%, and within 30 days if it is 10% or more. Do not leave it.

Why did it drain overnight?

Overnight use, a heater or air conditioner, or an oven can empty it. That is normal. Check it recovers with sun.

Does an empty battery void the warranty?

We cannot answer warranty questions from a web page. Call us.

Can I charge it from the grid myself?

Please call us. Changing modes or settings affects your blackout backup and bills.

Sources

Last checked 6 October 2026. Only the manufacturer’s, the network’s or the government’s own documents are used; app menus change between versions, so if your screen looks different, call us rather than guess.

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