Thor Forums

[Judge]

I still contend having the chassis battery and house battery cables has a negative impact on the BIM charging algorithm.

My proof is that after driving 6 hours, my slide would not extend because the house battery voltage was too..... even with the engine running to extend the slides. The BIM should have been providing more than enough voltage from the alternator to extend the slide! The first time it happened I thought I had a slide controller failure.

I had to start my generator so the Converter kicked into provide voltage to the house batteries to allow the slide to extend. Thats when I knew the problem had nothing to do with the slide itself.




The FireFly panel shows the wrong chassis battery voltage because there is a smaller gauge wire on the BATT-A post of the BIM where the chassis battery should be connected so it can monitor and report that voltage. Instead the house battery cable was connected to that post where the chassis battery voltage monitoring wire was located.

The voltage readings on your Inverter (and solar controller if you have one) will match the chassis battery voltage (and house battery voltage) when the BIM relay has engaged.

Now that I wired my BIM correctly, I can do an easy test to make sure it is working properly.

If I am plugged into shore power, I can turn the headlights on to drop the chassis battery voltage and once it hits ~12.6V, I can hear the relay engage to send voltage from the house batteries via the Converter / Charger to the chassis batteries. At that point the voltage on the Inverter and Solar Controller match the voltage of the chassis battery within 0.1V.

I can also do the reverse test and take the coach off shore power and start the engine. The I turn up the fridges and other items on the Inverter to drop the house battery voltage to 12.6V until the BIM relay engages to charge the house batteries from the alternator. Again the battery voltages will math within 0.1V at that point.