I have a pair of Multiplus inverter chargers 12/3000/120-50 operating in parallel. When I am connected to shore power, the AC loads are isolated, the DC breakers are isolated, and only the batteries are connected in float charging mode, I still see a 230VAC current reading of 1.1A on my shore power ammeter.
This looks like 260W of input power with nothing taking power out. My BMV700 battery monitors say that the batteries are taking less than 0.1A at 13V.
I would expect that a lightly loaded charger would take maybe 10 or 20W of idle power, but the readings suggest that 260W is going somewhere. Both Multiplus chargers are running cold, so I don’t think they are really taking 260W and turning it into heat.
Could something be fooling the ammeter into misreading? Maybe crest factor or power factor?