Okay I have read the article on The 12volt side of life but don't understand. I have installed a new PD 9245 Converter/charger but after leaving my batteries for a few hours it reads 12.2 volts. Is it not supposed to read 12.6v when fully charged. These are 12 volt Costco deep cycle batteries but one is older than the other but I feel I have abused them. But before I rush out and buy 2 6volt batteries i want to make sure these are no good.All I really run on the house batteries are Led light and a 12v fridge.

12.2 right after a full charge is not good. If you don't dry camp you really only need one 12v battery.

What does it read while charging? And when you measured the 12.2 are you sure there isnt a draw? Doesn't take much of a load to take it to 12.2.Get a specific gravity device and take readings of every cell. It will tell you if the battery is taking a charge. Also how old are they?

When it is charging it is 13.6. When I take the charge off it reads 12.26. When I turn on the fridge it drops down to 11.97I do boon dock so I need 2 batteries.

It is a basic that batteries should be the same age. when connected they default to the weaker of the two. Try separating and charging independently. Battery Faq

Batteries-Don't understand | Good Sam Community

16 Replies

crasster
Explorer II
May 19, 2016
Sounds like one is desulphated. Get a battery minder desulphator.
2oldman
Explorer II
May 19, 2016
thriftydutch wrote:
Before that I could run the fridge 3 to 5 days without driving or hookup.
As said, you're killing them.
bsinmich
Explorer
May 19, 2016
The 3-5 days that you could run the frig are the problem. You are getting the battery lower than they like. The frig will put out heat from a weak battery but it is also killing your battery a little every time you run it that low.
My_Roadtrek
Explorer
May 19, 2016
One weak battery will discharge the good one. Best to always replace in pairs wth same size, brand, and age.
time2roll
Nomad
May 19, 2016
thriftydutch wrote:
It's 120v-12v fridge. No propane. It is only in the last year and half that the batteries are not sufficient. Before that I could run the fridge 3 to 5 days without driving or hookup.
Three days on 12 volt? Wow I had no idea. Is this a compressor fridge?

Keep your batteries above 12.0 volts and they will last longer.
RedRocket204
Explorer
May 19, 2016
thriftydutch wrote:
When it is charging it is 13.6. When I take the charge off it reads 12.26. When I turn on the fridge it drops down to 11.97

I do boon dock so I need 2 batteries.

thriftydutch wrote:
If I am not mistaken one battery is 2 years while the other is 4 years old.

thriftydutch wrote:
It's 120v-12v fridge. No propane. It is only in the last year and half that the batteries are not sufficient. Before that I could run the fridge 3 to 5 days without driving or hookup.

I wouldn't even bother getting those load tested as this information is enough for me to say, buy two new batteries. Even if one of them is OK (but probably not because of the year delta), a new battery with a 2 year old battery is asking for reduced battery operation.

Buy two new ones.
thriftydutch
Explorer
May 19, 2016
It's 120v-12v fridge. No propane. It is only in the last year and half that the batteries are not sufficient. Before that I could run the fridge 3 to 5 days without driving or hookup.
bsinmich
Explorer
May 19, 2016
He could have a 3 way ref. I have one in my '95 Roadtrek and it will run on 12V fine while driving but goes down fast when stopped.
2oldman
Explorer II
May 18, 2016
Replace both.
thriftydutch wrote:
When I take the charge off it reads 12.26. When I turn on the fridge it drops down to 11.97
Fridge on gas?
thriftydutch
Explorer
May 18, 2016
If I am not mistaken one battery is 2 years while the other is 4 years old.