Battery question

Photomom

My dealer told me that we can upgrade a group 24 battery for more capacity - it would still be a group 24, whatever that means, and would still be the same size, but would have a higher reserve amp/hour rating. 


Can can someone explain? I was under the impression that all group 24 batteries were the same. 

Nomad

That's what I thought also.

jkjenn

No, it can vary. I have seen them at 84ah and 100ah.

Nomad

Jenn - Does it say on the battery which it is?

gilbutler

I did find a 100 ah group 24 by Trojan, but it is flooded and I want to stay with agm so I'm thinking of going to a group 27.

Photomom

Dealer says a group 27 won't fit. What would you have to do to use one?

jkjenn

This is the 100ah battery that the dealer had put in my T@b.

gilbutler

I checked outside dimensions on some group 24 and 27 battery boxes.  The group 27 box is almost three inches longer and a quarter inch taller with same width.  My trailer isn't here, but my memory thinks it will fit.  Of course, Jenn offers a reasonable solution.

Nomad

Just laying down under and feeling around the battery box frame it appears there is only an inch or so extra in length and 1/2 inch in width. Doesn't sound like a 27 would fit without a different frame. Didn't open the battery box to see if there was any extra space in there.

mash2

The innards of a battery can vary along several dimensions.

1. Area of plate surface.
2. Quantity, arrangement, and porosity of active materials.
3. Quantity and strength of electrolyte.
4. Circulation of electrolyte.

Different arrangements of these creates varying storage capacity inside different batteries with the same dimensions (Group size generally refers to dimensions of the battery , not the AMP capacity -- because of additional volume, group 27 can potentially have more of the good innards (surface plate area, etc., so are generally considered to have higher capacity -- but this is actually highlighted in the storage capacity measured in AMP's).  In general, most use Reserve Capacity as the measure (the number of minutes a battery can maintain a useful voltage under a 25 ampere discharge.  This gives an indication of the quality of the innards (surface of plates, quality of materials).   

Battery groups generally refer to the outer dimensions of the battery.  Group 24 is generally 10-11 inch length while Group 27 is generally 12-12 1/2 inch length (width and height are generally comparable between the two groups).  I remember having to build new platform to fit group 27 in my DM t@B because length of battery was too long. 

The battery capacity within Group 24 and Group 27 batteries does vary.  Look at a battery speciality store and you can see the range of capacity available at each group size.  As Jenn highlighted, Interstate has a 100 AMP Group 24 version (as do others) in deep cycle.   

While the group size indicates relative size, there is some variation in dimensions within each group.  You can measure the length of the current battery box to determine what is maximum size that can be accomodated (check width and height to ensure that the battery volume will fit in the space).  

Nomad

mash2 - Thanks

Lisa33

Aassuming that the cost difference isn't significant, I'd definitely opt for more AH.  

Photomom

He said the delta would be around $30. I'm for getting the biggest one we can stuff in there. Our first T@B summer we'll be taking weekend trips only and it would be nice not to have to deal with a generator while we're learning everything else. 

mash2

Second more AH.