[Archived]

Reading over all the posts in this thread and combining what was said, here is the breakdown:

1) Vantare did “screw up” in that both battery temp sensors are not connected to the same battery. I generally pick a middle battery in the “24v” bank section, in case there is a battery equalizer failure, or the single house equalizer cannot keep up and the 24v bank tends to get overcharged, resulting in getting the hottest. Those should be moved and then look at the Menu 21 temp readings. These values are “counts” not the actual temperature reading. On a Florida summer day the values should be within 5 “counts” of each other, and in the vicinity of 100-115, give or take.

2) With the inverters in the default charge amps setting of 15 amps AC, corresponding to about 75amps dc charging at 24v, the inverters will “fight” at the end of the charge cycle. The only remedy for this is to utilize the parallel stacking cable that was an option at original purchase. But the use of the stacking cable did cause its own issues on occasion, and a shutdown of one inverter would shut down the other as well, so no Prevost converter chose to install them. If the batteries are in good condition, this condition will only last the max of 3 hours though, as the one inverter times out in “bulk” charging mode, while the other is in “Float” charging mode. That is the condition people are seeing, where the inverter in “float” is actually inverting to lower battery voltage to the float value of 26.6vdc, while the one that is still in “bulk” is still trying to finish the charge at 28.6vdc.

In the above condition, if you look at input amps on each inverter, you would see one is drawing all the current from the cord or generator, while the other is actually inverting up to its 33amps rating and only taking current requirements above that from the cord or genset. I know people get alarmed by this condition, but is the temp sensors are on the same battery, this temporary condition will end when the “bulk timer limit” of 3 hours is met, and both inverters are in float mode.

3) If owners elect to effectively disable one charger by dialing the max charge amps setting to 0, bear in mind that recharge time will go up by almost a factor of 2. I suggest if you want to do this, pick the charger that does not wired to auto-gen-start (the lower inverter remote), so that the generator autostart will function properly. This is also the ac leg in a Vantare that tends to be the most “loaded up” anyway, so you also get the added feature of balancing out the 2 AC legs better as well.