I have come into possession of 2 certaUPS C200's and one works flawlessly but with slightly shorter battery life which will get sorted at some point but the other one turns on fine with mains power but lasts only a couple of seconds once the power is turned off even with no load connected, I have swapped over the batteries between the units which makes no difference to either unit so I'm happily that both battery sets are equally fine, inspecting the PCB of the defective unit I see no heat spots, bulging caps, cracked chips, blown fuses etc but what it does have is what I believe to be a failed...