question

bigsandybus avatar image
bigsandybus asked

Why is the BMV state of charge at 70%, while MPPTs are on float?

I have a victron 24/3000 multuplus inverter/charger, 2, mppt 250/60 charge controllers, and a battery victron smart monitor, 8 12v 155ah agm batteries paralle/series for 24v. My problem is as follows...the battery monitor says the batteries are at 70% charged but the charge controllers are both in float and say they are charged. My absorption is set to 29v, my float to 27v as told by my distributor. Why are the charge controllers In float if the batteries are not 100% on the monitor?? I think the settings are backwards but it is what distributor told me to set them at


BMV Battery Monitor
2 |3000
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Justin Cook avatar image
Justin Cook answered ·

@Bigsandybus, the most likely explanation for this is that the shunt for the BMV is connected improperly.

Please check that there is only one thing connected to your battery bank negative, and that is the "battery" side of the shunt. ALL other system negatives, including all loads, chassis grounds, the MultiPlus negative, your solar controller "batt" negatives, and any NEG busbars are connected to the "loads and chargers" side of the shunt, NOT directly connected to the battery bank.

If any charge sources are bypassing the shunt, the battery monitor cannot "see" them and therefore thinks that your batteries aren't charging.

Also check that you have correctly set your battery bank capacity in the BMV; your (8) 155Ah 12v batteries connected in series/parallel gives you a total capacity of 620Ah at 24v.

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bigsandybus avatar image bigsandybus commented ·

That was the problem, thank you so much!

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