I have a Cyrix connecting my starter battery (MB Sprinter) to the house battery and have a BMV712.
I use an AC charger to top up the house battery before a trip
Battery reads 13v +
During trip main load is fridge 6a @ 12v
The battery voltage as expected goes down over the trip
however when driving the battery is not charged and BMV shows 100% SOC always !!!!
TESTING - output of Cyrix is 13v+ - shunt seems to not allowing charge to get to battery
My initial thought is that the shunt is in the wrong place in the circuit or is not connected correctly.
Is it possible to show a wiring diagram of how these things are connected in your van?
HI
I have been on vacation so sorry for not replying earlier
Testing with engine running and house battery discharged :
1) If I test voltage between POS on the house battery and the ground when NEG disconnected on house battery I get 13V PLUS = output of alternator
2) If I test voltage between POS on the house battery and the ground when NEG connected I get House Battery voltage (ie 11V)
Charge is not getting to house battery
here is the basic layout
OK I managed to get the Cyrix to charge the battery now
It seems there is an order in which the batteries need to be connected
The status light was indicating ALARM - the Cyrix is mounted under the seat so I did not know the status until I removed the seat today
I disconnected everything and re connected and it went from ALARM to DISENGAGED
Then I started the engine and it went to ENGAGED and BMV indicated a charging voltage 13v PLUS
