12-Volt Battery Bank Upgrade - RPOD 176

We decided to upgrade our 12-volt battery bank that supplied off-grid power to our 2018 Forest River RPOD 176.  This post is about that upgrade.  I will share information about our original bank, why I felt it needed an upgraded, and then will show you the look of our final upgraded battery bank. 

Original Battery Bank

We only had one group 27 deep cycle marine battery in our 12-volt battery bank.  It was a battery stored in a plastic battery box that was attached to the battery tray on the A-frame of the trailer tongue.   It had 650 Cold Cracking Amp (CCA) marked on it.  The battery had two sets of wires running to it.  One set of wires were for the main power to the pod, and the other set was for the zamp solar panel connection.

Original 12 Volt Battery

Why We Upgraded

Everyone has their reason for a battery bank upgrade. Here are the main reasons we upgraded.

·       Didn’t know the age or state of the original batteries

·       Wanted a bank with more amp hour (ah) capacity 

·       Plan more boondocking in the future

Upgraded Battery Bank

Our new battery bank consists of 2 6-volt golf cart batterie at Costco.  I purchased these batteries at a cost of around $90 a piece, when I traded in two old battery cores.   The new Interstate batteries were flood-lead acid batteries, with a 210ah rating.

I hooked up the two 6-volt batteries in series to give me a 12 volts battery bank.  This upgrade gave me over twice the amp hour capacity of the old single 12-volt battery.  I’m hoping this equates to more time boondocking, while not being plugged in or running the generator.

Battery Boxes

I bought 2 golf cart battery boxes from Batteries Plus Bulbs online.  The cost of both of them combined was a little under $24.  These boxes filled up the battery tray completely on the A frame of the RPOD trailer tongue.

How to get 12-Volt Bank Out of a Pair of 6-Volt Batteries

In order to create a single 12-volt battery bank out of the 2 different 6-volt batteries, I needed to wire them together in series.   To wire together, I purchased a 19-inch 4-gauge starter battery cable from a local auto parts store for $9.33.  This battery cable was used to jump between the positive terminal on one battery to the negative terminal of the other battery.

Wired in Series  



Here are the steps I took to install my new 12-volt battery bank:

  •  Removed the old battery box. 
  •  Dry fit new golf cart battery boxes
  •  Drilled 4 drain holes in each new battery box
  •  Drilled 4 mounting holes in battery boxes, that went through battery tray (2 in each box)
  • Bolted down battery boxes with stainless steel bolts, and nylon lock washers
  • Wired batteries in series
  • Installed battery box tops and tie down webbing

Final installation

Things I discovered Doing this Project

With every modification there are things that get discovered. Here the list of things I found, as I installed my two 6-volt batteries into a single 12-volt battery bank.

·       The latches for the lids of the Battery Plus Bulbs battery boxes were hard to open and close, plus didn’t seem to always make a positive lock.   

·       Strap to hold down top and securely tie down the battery were hard to figure out and get working.

·       Battery boxes are very close to skin of POD

Final Thoughts

All and all this installation came out fairly well.  Only time will tell how well my $125 battery upgrade will works, and how the inexpensive battery boxes from Batteries Plus Bulbs hold up.   I will follow up on this upgrade down the road to share my thoughts on maintenance and the longevity of these cheap Costco 6-volt Interstate batteries.