I have the BMV 712 and I’m looking to make the voltage read what the battery actuality is. Is there a way to manually adjust the voltage for the drop I get in the long run of wire I have? The difference is around 1.3 VDC
asked
Starter battery voltage adjustment for voltage drop
Just how long is the run that you are getting 1.3vdc? Sure you don't maybe have a Diode in there causing extra Forward Vdrop?
Is there any load on the Starter from the system where teh BMV is located, as that will cause a drop?
Assuming for instance only 2.5mm^2 cable - over 5 metres, and 1A current, you should see no more than 0.09v - and that is WITH a load.
at 10 Amps - 0.9v
to get 1.3 v by calculation I had to look at 36m and running 2A of current.
I would be considering a change in cable before looking at adjusting settings. If it definitely was a TRUE 1.3vdc drop - best you could do would be increase/decrease the alarm values with that offset value. It will never show the correct voltage, but if you are using it to also trigger trickle charging such as from Solar or a relay from a Solar bank, then it would suffice, although you would also have to do similar to your charge source anyway - and that could have other consequences, so not really advised.
The run is about 40 feet of 24 AWG twisted pair. The voltage shown at the battery is higher then what the 712 shows. I'm just wnt it to show the correct voltage.
Is there a way to make the adjustment, Yes / no?
They should give us the option to allow for voltage drop.
There is no way that I know of to adjust for volt drop and like "crazy-marty" says you should have no volt drop for just monitoring the start battery. Double-check the red monitoring wire and fuse holder that came with the Victron unit. Mine was faulty from the factory and gave me incorrect voltage from my start battery.
