What size are these batteries?

[karrlot]

Karr Family Kamping Bus: Bat-trees

In this link there are pictures of my batteries. How do tell what size they are? There is nothing g written in the spots for part no., Cranking amps@ 32F, or cca@ 0F.
The only identifying g info is "Deka Maintenance Free, Dual purpose starting cycling power"

I want to check o. Prices for three new batteries but I need to k ow what size.

[SR2K]

Looks like a group 31 battery.

[2kool4skool]

Agreed... Measure them to be sure.

[karrlot]

You mean measure the size in inches? 8 1/2" x 13" x 6 3/4".

So are the different group numbers based on physical size?

[SR2K]

Battery sizes are done in "groups" so a group 31 battery is a specific size and power. Go into an auto parts store and ask for one, they're around $100-$120 typically.

[karrlot]

But can you tell the group number based solely on the size or do you also have to know the power?

[EastCoastCB]

Your bus either came with a couple 31's or one 8D, most likely.

[SR2K]

Group 31 is extremely common for buses, pretty much the standard battery, and your dimensions are correct. Thats what they are.

[2kool4skool]

Originally Posted by SR2K

Group 31 is extremely common for buses, pretty much the standard battery, and your dimensions are correct. Thats what they are.

[cadillackid]

that looks like group 31.. and a lot of bus battery trays are designed to hold 3 group 31's ... many busses only have 2... is nice that you have 3!
-CHristopher

[karrlot]

Thanks for the help everyone! I took them to the auto store to get tested.

They are four years old so I am betting I will be making an investment in new batteries.

I have another question about wiring. If you looks at my link on the third picture you'll see that the batteries are wired in parallel. I thought I read somewhere that when you do this you should have the positive cable be on the first battery and the negative cable hooked onto the third. That insures that all three batteries are used equally. You'll notice on my batteries there are three different positive cables (one is just a small wire) hooked o. To three different batteries.
The negative cables are hooked to two different batteries.

Should all of the positives be on the same post (on battery #1) and all of the negative cables be on the same post of battery #3? Does this matter?

[roach711]

Originally Posted by karrlot

I thought I read somewhere that when you do this you should have the positive cable be on the first battery and the negative cable hooked onto the third. That insures that all three batteries are used equally.
Should all of the positives be on the same post (on battery #1) and all of the negative cables be on the post of battery #3? Does this matter?

Having the positive and negative cables on the opposite ends of the bank ensures that they all get the same charging current.

[Stu & Filo. T]

My geuss is yay big by so big.

Come lighten up.

:

[Robin97396]

You lost me somewhere there. It almost sounds like you've got a combination of series and parallel circuits on your batteries, but that wouldn't be functional. It has to be a parallel circuit, otherwise you'd have a 36 volt setup.

[Brad_SwiftFur]

Last time I bought Group 31 batteries, I got 4 975 CCA for ~$80 each (needed 4). Of the old ones, one was dead, one was marginal, the other 2 fair. But then again, an ISX Cummins needs a lot of juice to start in cold weather.

[EastCoastCB]

Originally Posted by Brad_SwiftFur

Last time I bought Group 31 batteries, I got 4 975 CCA for ~$80 each (needed 4). Of the old ones, one was dead, one was marginal, the other 2 fair. But then again, an ISX Cummins needs a lot of juice to start in cold weather.

When I needed batteries Rural King came through with a sale. $75 apiece for 31's.

[karrlot]

Originally Posted by Robin97396

You lost me somewhere there. It almost sounds like you've got a combination of series and parallel circuits on your batteries, but that wouldn't be functional. It has to be a parallel circuit, otherwise you'd have a 36 volt setup.

No they are all in parallel. However I have ave three different positive cables and three different negative cables that need to be hooked up to the batteries. I would guess one set is from the engine, the second set is from the drivetrain retarder, and a third (much smaller) set is going to the coolant heater.

[karrlot]

Originally Posted by Stu & Filo. T

My geuss is yay big by so big.

Come lighten up.

:

You say you've been lightin' up?

[Robin97396]

It's a morning thing for retirees.

[Stu & Filo. T]

Originally Posted by karrlot

You say you've been lightin' up?

It's my blue tooth key board on my iPad, it was supposed to say come on lighten up, sometime I hit enter to fast without going back to see what it missed