We have a 48/10000 Multiplus II, coupled with a cerbo gx mkII, victron isolation transformer sitting between the AC-In and the inverter’s AC-In, a viltron mppt for solar, 3 x Fogstar 16.1KWh solar batteries with lynx power-in, lynx 1000 shunt, lynx distributor, this is all coupled with a Zeus Controller for our 48v Zeus alternator.
Now most of that info is irrelevant but I wanted to highlight the nature of the setup.
We have a portable aircon on our narrowboat (and boy have we been glad of it this week) when we turn the aircon unit (it draws about 1250w 240v) our AC in drops back from about 1800w (we can only pull 9amps due to the installed breaker at the marina) to 700w - 800w this can be for some time, maybe 30mins to an hour and then it will ramp back up (sometimes not consistently), but it ebbs and flows - it doesn’t seem to affect it if we have solar coming in via the mppt or not but for an overall draw of approx 1500w discharging the batts when shore power is available but not being used seems a bit odd… and the thing is the only situation that causes this behaviour seems to bee when the aircon unit is on, it doesn’t do it with any other draw eg: electric oven, hob, espresso machine, washer/dryer drying none of these cause the overall system to exhibit this behaviour - only when the aircon unit is on…
We are 48v, shore power is 250v - VRM will show us pulling 8.3a but only 700 - 800w (which of course also doesn’t make sense in my head) the ambient temp in the boat is approx 24c and the electric cupboard is open and ventilated. Battery temp is stating 27c which is also pretty standard temp for these batteries.
Would appreciate thoughts/input on why this odd behaviour seems to occur…