What does Growatt error 04 mean?
04 means the battery voltage or charge is very low. A flashing red light with a beep every second is a warning: the battery needs charging. A steady red light is a fault, and the inverter has cut its output.
Why does code 04 appear?
- Heavy load overnight drained the battery.
- Little sun or dirty panels meant the battery didn't fully charge.
- The battery is old and no longer holds charge.
- A loose battery cable.
What can you safely check for 04?
- Switch off heavy appliances to reduce the load.
- Let the battery charge when grid power or sunshine returns.
- With a lithium battery, check the battery percentage (SOC) on the screen.
- If the panels are dusty, rinse them with water in the morning or evening.
Safety: never reach into an electrical panel, board, gas pipe or the inside of an inverter yourself. You can get a shock or release gas. This is a mistri's job.
When should you call a mistri?
If 04 comes back soon after a full charge, call a solar mistri to check the battery and cables. An inverter carries DC current from the panels and battery that can kill, even after the mains is off. Never open the inverter cover or the DC wires yourself.