12 volt or 6 volt cabin batteries

[Mike in Va]

A friend of mine has a 93 Tiffin allegro 8.3MH. He was getting ready to replace his cabin batteries and decovered that there were 4 12 volt deep cell batteries instead of the 6 volts he was expecting. He doesn't know if the MH came with 6 volt batteries and someone changed them to 12 and can't find anything in his manuals that address it. He was also wanting to know if the 12 volt deep cell batteries were better or lasted longer them 4 6 volts deep cell. Both of these questions are above me so I thought I would put it out to people who do know. Thanks for the help.    

[Ivylog]

Until I recently went to Lithiums, I used 12V AGMs mainly for the no corrosion. 6V golf cart batteries are the cheapest option. Unless you dry camp a lot, I would go with 2 good 12V deep cycle.

Edited January 27, 2023 by Ivylog

[1nolaguy]

Similar to Ivylog we changed a few years ago to from Lead Acid to LiFePO4. Since then the available options and prices have dropped for these to make them even more attractive then Lead Acid, so that may be something you should investigate and consider. As to 6v vs 12v, if the current system is 12 v there are some extra things you might want to take into consideration: 1) weight - 6v gulf cart batteries are heavy; really heavy. If you are doing this yourself physical limitations are a consideration. 2) 6V connections require thicker cables than 12v. Depending on your current system you may need to change out cables from say 2-0 to 4-0 and they can also be pricey. Food for thought.

[vito.a]

Many of the early coaches came with the large "8D" deep cycle batteries.   They rarely last more than 3 years and are expensive as well difficult to handle.  

I replaced ours with Trojan T-105 GC-2 size golf cart batteries.  They are heavy duty 6-volt batteries designed for constant discharge/charge.  Our last set lasted almost 10 years. 

You will need four GC-2 6volts to replace the two 12v batteries.  Make or purchase two small jumper battery cables to go from + on one to - on the other so they form two 12volt pairs.  

[willbo777]

I have 4 Lifeline 4D's as my house batteries.  I have replaced them one time in the 15 years we have full timed in the coach.

[Steven P]

Does he have 4 12V for just the house batteries? Or 2 12 V for house and 2 for chassis?  I don't think ive seen someone have 4 12V for the house, but I'm sure they are out there. My coach would need a bigger battery bay for those.  The PO of my coach had 2 12V deep cycle marine for the house, but they were bad.  I feel they did no boondocking and used the genny a lot.  I changed to 4 6V Trojan t105 AGMs for more capabilities.  Had to do some wiring and spent more money that way,  but I preferred to have more boondocking options.