Thor Forums

[petefoss]

Originally Posted by TLeenhouts

If you plug in a battery tender or charger to the engine battery while not in use, the BIM (battery Isolation Module) will not be energized and you won't charge the house battery. I have just gone through this for a neighbor and found that a LOT of BIMs are bad. Hers failed in the ON position so that you never really disconnect the engine battery which draws it down. The BIM is energized when the key is turned to the ON position. It is deenergized in the off position. Also, if you are plugged in to shore power, the converter/inverter should be charging the house batteries as long as the use/store switch is in use position. If it doesn't charge the batteries, there is a problem with the wiring or the converter. Just because it's relatively new does not mean that it works. The emergency start relay in my neighbor's unit was wired improperly from the factory and Camping World did not honor the warranty charging them almost a grand to fix it.
Just sayin'.
As a sidebar, my Windsport has TWO disconnect switches, one for the engine battery and one for the house batteries. Works like a charm and I have never had a problem. I also don't trust the bar graph idiot lights for the charge state so I removed my panel and wired in a voltage monitor. When I'm plugged in, the converter supplies 13.5 volts. When the generator is running, it supplies 13.5 volts. When the engine is running, the alternator supplies 14.4 volts which gives a full charge. It also lets me know what voltage is left in the house batteries any time the batteries are in USE mode.

If you have an inverter, it's display works fine to display the coach battery voltage. Just remember to not leave it on if you are not plugged in.