Charging chassis batteries

If I put a battery charger on the posts of the outside chassis battery, will it charge both?

Fifty4F100 wrote:
I'm still puzzled as to how the chassis batteries died. I thought the coach couldn't pull them down.

There are always ghost draws on Diesel Chassis Batteries. That is why most OEM's have a Dual charge system or like the Tiffins a 120 volt battery Maintainer for the chassis batteries. You can stop this type parasitic draw by either disconnecting the Ground cable at the chassis battery or in the Tiffin system it has a manual battery disconnect. Doug

I'm still puzzled as to how the chassis batteries died. I thought the coach couldn't pull them down.

Tiffin Breeze as well as all current Tiffin models use a Trickle type Battery Maintainer for the chassis batteries. That means IF your chassis batteries are completely dead, that Small Maintainer cannot charge completely dead batteries. So, using the Battery Boost switch, hold it down or use a toothpick to keep it engaged for at least 1 to 2 hours while plugged into Shore power. That will allow the Coach Battery charger to charge the chassis enough to let the Maintainer start up and then fully charge the chassis batteries. It will take a week or so. I would leave the Toothpick in the Battery boost switch for 24 hours and then remove it. The chassis Batteries will almost be fully charged by then. Doug

You would be wise to check battery voltages while you are charging to see if your batteries are actually getting the voltage from the converter.

You may also have a Bi-Directional Relay that is stuck in the closed position. This relay allows charging from either side to flow to the other side. Normally, the chassis battery while running charges the coach via an isolator, but with a Bi-Directional Relay if the coach battery is higher than the chassis, charge will flow that way.

I had one once that stuck in the closed position. Any drain from either side would then drain all batteries equally. In a week, you can lose a lot of parasitic power... did you leave a fridge running?

Check voltages, see what you have with no charge voltage, and what you have while charging. A meter tells a lot.

Fifty4F100 wrote:

2oldman wrote:
a good battery.

I have 2 reasonably new AGM batteries.

Good, meaning charged. Just a guess of course. But there ain't no battery power there.

Taking a long time to come alive can mean something has drained them.

2oldman wrote:
a good battery.

I have 2 reasonably new AGM batteries.

Southwind98 wrote:
Couple of weeks ago my RV had the same problems, turns out the positive cable was slightly loose. I would tighten both negative and positive connections.

Its a DP so it has 2 batteries. I'll check the posts.

a good battery.

Couple of weeks ago my RV had the same problems, turns out the positive cable was slightly loose. I would tighten both negative and positive connections.