Battery Voltage drop under load
Is a voltage drop to 12.0V to be expected with a 21.3A load with a fully charged ~216Ah battery bank? I've never loaded the batteries that much before, so really have no idea what to expect. It...
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You need an ammeter to follow the action. The voltage drop you are seeing is a little higher than it "should be" but you also have the solar on which confuses things.
The amps in from the solar would make the amps draw from the fridge net less from the battery and hold up the voltage a bit higher, so perhaps your actual situation is worse (but it is not a calamity, just more than it should be)
You can help by improving the inverter-battery path (fatter wires and tighter connections) but there might also be less capacity in the batteries than you think, since you have not been checking on them all that much and they might need at least a good equalization session to bring their "at full" SG back up some
I get about 0.8 drop with a 70 amp draw on four 6s but that is just my set-up. Others would get more or less than that with theirs. with two batteries instead of four you get more drop. With AGMs instead of Wets you get less drop.
Some inverters are better than others too for amps draw. My older 2000w Vector (now moved to the truck camper from the 5er) pulls 90 amps to run the kettle but my newer Can Tire Xantrex 2000w using the same wires and batteries pulls 80 amps to run the same kettle.
The amps in from the solar would make the amps draw from the fridge net less from the battery and hold up the voltage a bit higher, so perhaps your actual situation is worse (but it is not a calamity, just more than it should be)
You can help by improving the inverter-battery path (fatter wires and tighter connections) but there might also be less capacity in the batteries than you think, since you have not been checking on them all that much and they might need at least a good equalization session to bring their "at full" SG back up some
I get about 0.8 drop with a 70 amp draw on four 6s but that is just my set-up. Others would get more or less than that with theirs. with two batteries instead of four you get more drop. With AGMs instead of Wets you get less drop.
Some inverters are better than others too for amps draw. My older 2000w Vector (now moved to the truck camper from the 5er) pulls 90 amps to run the kettle but my newer Can Tire Xantrex 2000w using the same wires and batteries pulls 80 amps to run the same kettle.
