Battery Isolater Problem?

[BrunoMTP]

Greetings all,

Am currently in the process of testing Lifepo4 batteries for boondocking and adding solar and have encountered a problem that appears to be a battery isolation problem between the house batteries and chassis battery. Testing results are as follows:

Charging with installed WFCO 8945AN (Standard LA charger) charges Lifepo4 battery to 13.5 while charging and 13.4 at rest (waiting about 10 minutes) Chassis battery reads 13.5 at top of charging as well.

After disconnecting charger and sitting overnight, (~ 12 hours), lifepo4 battery reads 13.1 Volts, and Chassis battery also reads 13.1 volts at rest. This is with converter / charger turned off, batteries connected to the coach, but no overt loads connected. Hypothesis is that the house batteries are being drained into the chassis battery.

Repeated test with stand-alone 20 amp continuous lifepo4 charger and both House and Chassis batteries charged to 14.5 volts. After sitting about 12 hours rest, both batteries are sitting at 13.2 Volts.

Have noticed previously that when both House and Chassis batteries were LA, Chassis battery drained along with house batteries when boondocking down to the house battery level.

Questions: Is further testing needed and if so, what testing?

or is it time to consider replacing components? If replacing parts, which parts?

Pictures of system follow:

Thanks in advance.

 

[BrunoMTP]

Found a couple of older posts on this one (It's the B.I.R.D. causing this). Will review and update here if a solution is not found in the earlier posts...

 

[John From Detroit]

The problem is indeed the B.I.R.D. the way it senses "Time to connect" is by looking at the voltage.. This is much simplified but less than 13 both sides = Isolate. More than 13 on either side = Connect.
And the LiFePO4's have a voltage that's high enough to "Connect".
How to prevent this. I do not know but I suspect a different isolator controller will be needed if it is not adjustable