When connecting the charger to various batteries I tend to get a higher voltage displayed on the Victron App than measured across the battery terminals (using Smart BMV 712 + normal voltmeter). Example. Charger set on HIGH, App voltage says 14,7v but battery voltage says 14,6v. Could Temperature compensation cause unit to drop voltage but still display the expected voltage on the app?
First of all, to load a battery, a charger need to force a higher voltage on the system then the battery voltage, otherwise no current will flow into the battery.
So this might be the first point why a charger shows up a higher voltage then the battery has. Without load, this should be almost the same. When you say you measure 0,1V less then the MPPT charger, this might be within some tolerace... and are you sure your meter is correct? ;-)
Regarding the question from @Gunnar_L, this might happen when the BMS (is there a BMS) in the battery turns off charging as the battery is full, then the voltage on the charger can also rise up.
But, of course, there might also be defect in the charger...
Hello, i have the same problem wih my IP65 12/15. My dealer means, this is normal. But i dont think so. Any other charger loads the batteries on the terminals with the correct voltage. After a change of the charger, the voltage difference of this new charger is smaller. But after few hours of charging, display the charger a error. Overvoltage of the battery with 21 volts. This is completely impossible and the voltmeter shows the normal voltage of 12,7 volt. I think this product has a very low qualitiy.
@Jetlag The batteries dont have a BMS. They are normal acid lead batteries. If i want charge one of these batteries, i set charger to normal charging - 14,4 volt. If it arrives absorbtions voltage of 14,4 volt the victron charger shows this voltage on display. If i use a voltmeter on the terminals, it shows 14,1 volt. Thats in my opinion not normal.
Ok, this sound weird to me.
Did you maybe try some other battery to check if the behaviour is there the same? Ortherwise I would also say this seem to be some defecive part...
@Jetlag Yes. I tryed it with 4 batteries. All the same. Other chargers shows the right voltage on the terminals.
Then you should try to get this charger replaced...
