As in, an inverter, to connect to an external battery, that also has a mains socket, and will charge the battery..
I bought a lot of faulty ones... Apparently, the switch over circuitry wasn't working...
Now, if I JUST connect mains, sure enough, it doesn't switch to the output socket..
However, if I connect a battery, and mains, it appears to switch the output between the mains input, and inverter just fine...
But the question is, is this normal?
I've just tested a second, and it appears to function as the first one did....
Any input would be great... I was about to tear one completely down till I realised this...
Also, the charger output won't output anything either, unless the battery is connected when the UPS is turned on... you can even disconnect the battery once its on, and the switchover circuit remains active, and the charge circuit still outputs 13.8volts
Thanks!