I had a similar problem with my Mecer SOL-1-BB-M2L 2Kw inverter.The battery display showed a o present display on the front screen and wasn't taking any charge from mains or solar.I followed the advice given by Mustek and reset my inverter battery state back to 100 present.It is now working as normal.Thanks a lot for your assistance and that you posted your problem and saved me the trip to Mecer.