Battery Capacity

[bilmet01]

Has any MBS owner been able to successfully install 2 group 31 FLA house batteries in their battery box? I have a 2015 Forrester 2401S and I measured my battery box in the stairwell as 10"H x 27.5"L x 7"W and the typical group 31s I am seeing are listed as 9.625" x 13"L x 6.75"W so not sure if I will be able to fit them? Also, I saw in a past thread of somone able to install group 27 FLA s at least?

Would have liked to install 6V golf cart batteries but know they will not fit. :-(

[Mikegjax]

Group 27s are standard. I installed two 27 AGMs in mine last year.

[DaveJordan]

If the issue is the height of the batteries, I'm pretty sure I've seen reference to a pretty easy fix of removing the step tread, adding wood strips around the top edges of the box, then reinstalling the tread. Makes the step heights uneven, but can get you more vertical space.

[Iceman from McMurdo]

AFFIRMATIVE on the Group 31 Battery Upgrade. We have the Sunseeker 2400W (sister ship to the Forester 2401) and they fit just fine if you remove the flimsy little battery hold-down straps at each end of the battery bay. It's a tight squeeze, but once you get the first one in the trick is to slide it ALL the way over to the side, which then allows just enough room to drop in the second one and then marry them up. We picked up our pair of Duracell Group 31 AGMs on sale at Sam's Club a few years back and they definitely provide some extra reserve capacity over the smaller Group 27s. Getcha some!

[bilmet01]

Thanks for the input everyone!

Note: I bought my RV used this past fall at my local dealer and it came with Optima Bluetop D34M AGMs ( not true deep cycle ) that looks like they are failing full charge. I figured they were not dealer supplied originally. Will think about the Group 31s some more else just go with the Group 27s. 👍

[FFred]

"Will think about the Group 31s some more else just go with the Group 27s. ��"

Whatever size you chose be sure they are true deep cycle batts.

GR 31 are frequently truck start batts , not at all useful as house batts.

[bilmet01]

Roger that FFred! 👍 Thx.