battery connection

Show us a diagram of your connections.

We also need to know what you are charging these batteries with. If it is a CONVERTER/CHARGER we need to know the model number...

I also don't know what a 2007 TOUR is as well...

Roy Ken

These 3 batteries.......all of them are 12V (not two 6v and one 12V?

Are batteries all the same age/size/amp hour?

Are positive and negative cables coming off of that first battery?


Better load balance/charging is for positive off one battery and negative off of other battery at end of bank

RoyB wrote:
I also don't know what a 2007 TOUR is as well...

Winnebago Class A

What Old-B is trying to say is if both the + & - leads come off on the same battery, not like his diagram you will have the problem you posted.

the batteries are all the same size 29HM 225 mins @23amps all neg are tied together and pos tied together with one pos tied to first battery and neg tied to third battery the charger is a inverter/charger three stage there is another set of cable that are connected just opposite of the first I'm thinking this is for connecting the coach batteries to house 2007 winnebago tour
Thank

You could swap the boiling battery with the 2nd in line and see if the same battery continues to boil.(it will). You have 1 defective battery(the boiling battery). You need to replace all 3 with the exact same brand and type. NEVER mix new and old batteries or brands. Doug

wire them in a balanced manner--only method #3 at the smartgauge site will work.

correctly interconnecting multiple twelve volt batteries

Others may say it doesn't matter--but unless there is a compelling reason to not optimize charging and discharging why not do it the best possible way?

Here is a video of 3 twelve volt batteries that have been wired in an unbalanced manner for 2 years. They have been equalized. The test shows how CCA has been adversely affected.

unbalanced for 2 years

I doubt unbalanced wiring causes the 1st battery to get hot. Running a MW for 4 minutes might, however.

Check the SG in each cell of each battery. You could also have a shorted cell. If you have a bad cell that battery will be down in voltage and will keep trying to charge.

If you can afford to have the DC disconnected for half an hour do that: Take the over all voltage then isolate each battery and check individual battery voltage. Wait 30 minutes to an hour and check each battery voltage again. I'm betting one battery, the one that needs the water, will be lower.

Report what voltages you get. If one is noticeably lower you could leave it out of circuit (reconnect the other two) over night or more and see how low the voltage goes. It could be shorted or sulfated. Sulfation may respond to equalization.

I don't know why Winnebago does this.....put in three 12 volt batteries on their DP coaches. If you end up with a bad battery, you'll need to replace all three as mentioned above. This would be a great time to take measurements and install four six volt batteries. You'll be better served. I know that on my sister's Winnebago (Itasca Meridian). there was room for four six volts where the three twelve volts were located.