Growatt Warning 20 warning: BMS communication error
Call a qualified installer
Urgency: medium
What it means
The inverter has trouble talking to the battery's management system. An installer should check the battery link.
Likely causes
- Battery communication problem
Don't try to fix this yourself
When to call a pro
Call a qualified installer now. Switch off heavy loads and don't try to repair anything yourself.
Solar systems carry dangerous voltages. Only do the safe checks listed. If unsure, call a pro.
Source: Growatt Off Grid Solar Inverter SPF 3500 ES / SPF 5000 ES User Manual v4.0 (paraphrased)