Chassis Battery Charging

[davidbrady]

That is a good feature Chuck. My Vantare doesn't have a separate generator battery. Instead I have a switch which allows me to jumper the generator to either the house or the chassis battery bank.

Folks,
Chuck and I ran into something interesting with the Prevost 24V chassis bank, or for that matter, any 24V bank made up of 12V batteries in series. Turns out the better way to charge these 24V systems is to use a two output 12V charger as shown in the attached pic. If instead we use a single output 24V charger then we run the risk of over charging one battery in the series while attempting to fully charge the bank. This is true of any bank made up of series connected batteries and is why Li-Ion work best with battery management circuitry. The battery management shunts around fully charged cells in the series so that lesser charged cells can be brought up to charge. The is called "balancing" the cells in the bank. In a 24V chassis bank there are 24V loads and 12V loads which can cause the 12V lead acid batteries to become discharged relative to one another. Attaching a two output 12V charger does a better job of keeping the individual 12V batteries in balance then does a single output 24V charger.

Our banks, both the house and the chassis, are typically 24V which means the house batteries with their dual 24V Trace SW4024 chargers suffer from the same imbalance problem. The Vanner equalizers function as battery balancers eliminating the problem. They do this by monitoring the center tapped 12V battery and the 24V battery and funneling current from one to the other. The trouble with the chassis bank is that when the key is turned off the chassis Vanner is also turned off so we lose the battery balancing effect.