concern over battery banks

[davidbrady]

Hi Greg,

Normally BB used a 4 position battery cutoff switch similar to this Blue Sea switch, but BB only used it for a single battery bank so having the switch in position A is the same as having it in position BOTH, and OFF is the same as having it in position B. I think BB did this because at the time the four position was cheaper than the two position as pictured here.

The three shunts are for (1) alternator ammeter gauge, (2) coach loads, and (3) battery charge, which are the gauges on your dash and overhead. If the battery disconnect is wired properly then you can completely remove your house bank from the circuit. In this case the only way the chassis batteries will deliver power to the house or to the inverters is if the aux-bat switch is thrown. If that happens then you need to see what the gauge of wire is from the chassis batteries to the shunt and use the calculator at the bottom of this page to see if you're okay, keeping in mind your common amperage use and transients. The calculator shows a 3.5' run of 4/0 can sustain 1000A with only a 3% voltage drop.

You might find this charging circuit interesting. Unfortunately it's for a WB; I'm unable to find a similar diagram for the LXi.

Hal, that's a Class-T fuse in a rather unfortunate wrapper.