We have a 24 V / 2000 VA / 50 Hz MultiPlus Compact inverter which has worked perfectly for 2 years now. Suddenly 2 days ago it has not gone into inverter mode when we have a mains failure and the "red" alarm light just stays on permanently. When the mains are on the charging light is on and flashes. I have checked the DC output fuse and it is perfect still. Ive checked the battery no-load voltage which is 26V DC. However i did notice when i turned off the mains this battery voltage dipped to 17V Dc briefly before the "red" alarm light came on again and there was no output from the inverter again. I checked and there is no sign and no smell of anything burning. Can you advise what the fault might be. I should advise that i suspected the batteries - but until 2 days ago the inverter was able to run our full house lighting load , plus TV and WiFi easily for 2 hours so im not sure its suddenly the batteries. Any advise will be appreciated.
