Hi, I have a BMV 702 Battery monitor in my camper. The main battery is a 105Ah AGM, and I have recently added a 2nd 105Ah AGM to increase battery capacity which was pre-wired ready to accept a 2nd battery when I purchased one.
My question is - Should the battery capacity for the calculation of state of charge be set to 210AH representing the new total battery capacity or should it be set to the capacity of the individual batteries. The manual is not clear on this point.
If you have kept it as 12v then the capacity did double. (So 210AH)
Thankyou. Yes it’s still a 12v system.
Hi Brett,
When batteries are connected parallel, then the Voltage remains the same, but the Ampere hour (Amps) of each battery is added resulting in an increase in the total capacity. In your case, if the batteries are wired in parallel then yes it would still be 12Volts and as LX stated the battery capacity would now increase from 105Ah to 210Ah (105Ah+105Ah).
Yes you need to update the battery capacity settings for the BMV so that it knows what capacity it is dealing with.
The BMV will on first power-up detect the total battery capacity, this is also the case for MPPT charge controllers.
There are two additional methods to make changes to the settings in the BMV.
If the battery was added after the initial power-up then take a look at section 4.3.1 changing settings from the BMV head unit display:
This shows the steps to change settings at a later stage. The link above specifically shows how one could change the battery settings and capacity.
4.3.2 also explains how to apply changes to setting via the Victron Connect cell phone app.
One would also need to use VEConfig to set the correct battery capacity on the Inverter you are using.
Hope this helps.
Thankyou