Group 24 to Group 27 Batteries in my 27ft International

[BoldAdventure]

Greetings! As usual, documenting everything I do.

Last week I decided to replace the very old and warn out Walmart Everstart batteries the previous owner had installed in our Airstream with a new set from Costco. Just plain jane Interstate lead acid batteries. Well aware of all the perks of AGM or even moving up to Lithium. But not this month.

The Group 24 replacements where $72.99 a pop at Costco, with a core return that came in at 148.98 with FL tax.

Then I got to thinking, why not just jam some bigger 27's in the battery box.

Type 24's have about 75 to 80 amp hours of capacity, or 150 to 160 total (depending on battery maker). Two 6V golf cart batteries will give you about 220 amp hours of capacity. And the two type 27's are around 200 to 210 if I remember correctly.

So I returned my batteries to Costco and got Group 27's which is Coscto fitment code 14.

The difference in price is marginal for the extra power. $78.99 per battery. So literally $6 more per battery.



Here's the skinny on replacing your group 24 batteries with group 27s:

• remove battery cables (negative first)
• pull the batteries and remove the threaded rod (should be a nut welded to the bottom of the battery box.
• the plastic tray is unnecessary and you can trash it.
• drill out the 3 rivets holding the tray to the forward edge of the box and remove the cover.
• remove about 3/8-1/2" from half of the forward tray lip with an angle grinder (you may find it easier if you remove your LP tanks)
• file, prime and paint the cut edge however you like
• place one new Group 27 in thru the new slot and slide it to the opposite side of the box
• replace the threaded rod
• place the second Group 27 into the box and secure the batteries with the wing nut
• re-attach cables (positive first)
• re-rivet the lid or use bolts if you prefer and replace LP tanks and cover
• YOU"RE DONE!!!

If you're really brave, there is a thread somewhere in this section where someone supposedly squeezed group 31's into the battery box. Good luck with that, I'd assume you'd be better of just going to 6V at that point.

[BoldAdventure]

Trojan Batteries 31xhs fit with the same modification for 260ahs

31XHS | Trojan Battery Company

Photographic proof

[cwf]

Close to the metal .... Watch for electrical shorts!

[BoldAdventure]

Originally Posted by cwf

Close to the metal .... Watch for electrical shorts!

Not mine, http://instagram.com/p/twH0vTQLXN/?modal=true

But, I'm going to assume from our comment discussion and his comments on mine, he cut his in the same place, which would mean while it looks close in the picture, it's not "that close".

But you're right.

I just wanted to include the reference and photo here for anyone looking for alternatives to 6V's and making the battery box deeper or taller.

Cheers.

[tjdonahoe]

You pulled out old Interstate batteries, never seen them at wallmart .They re a good battery,also have a costco in my boat, they are cheaper....but have. Good warranty

[Phoenix]

Could you please explain in a little more detail...

Did you raise the cover to provide more clearance between the lid and the battery terminals on the group 27's? If so, I'm not quite sure what was done.

Thanks.

[BoldAdventure]

Phoenix, no modification beyond trimming the back wall. These batteries are the same height. So are the Trojan 31Xhs's. They're also the same width. But just an 1/2 inch longer. So you need to trim that edge to drop them in.

The Traveling Haywoods modified their box a little different from me, where I cut all the way across the back, they cut a smaller notch and slide the battery over.

[Gsmblue]

Brilliant!!!

Add to the job list!!!

[BoldAdventure]

Originally Posted by Gsmblue

Brilliant!!!

Add to the job list!!!

The 27's where only a few bucks more than the 24's. Now I will say this, those Trojan 31XHS are a 12v 130 Ahr. flooded battery. And they're looking very appealing to me.

AGM's cost more money, weight more and usually have less amp hours when compared to other Trojans or Lifelines.

I don't mind the light maintenance that flooded batteries require, and I don't plan on discharging them in freezing temps.

Here are the specs: 31XHS | Trojan Battery Company

They weight 67lbs each or 134lbs total.

Compared to the 6V T-145 Plus some guys run, also 260ahs but at 72lbs or 144lbs plus the additional height and metal you have to add to your battery box.

I think you can see why this might be an appealing alternative.

I'm going to run out these 27's for awhile, but I think the 31XHS is in my near future.