Two battery set-up
I am wanting to add a second battery to my TT to increase the amount of time I can run off of 12 volt. Anyone else done this and what size batteries should I be looking at??
Forum Discussion
kgarrett9999 wrote:
I bought a switch that allows me to choose either battery or both or neither. Since my batteries are of two different sizes, I don't intend to ever use them at the same time, but the switch allows it if/when I replace them. My idea is to use my primary (larger), but always keep the 2nd battery as a spare in order to be able to run the slides, tongue jack and emergency brakes should I run the primary down too far.
This is an OK system but you need more than a single switch or you need to always be keeping an eye on the switch.
If you want to do it manually, you have to remember to move the switch to "both" once hooked up and then back to one battery once parked. If you forget you get one of two conditions:
- It's always on both and you always use both battery banks, so you've only added complication for no benefit.
- It's always on 1 bank and the other is dead when find out you need it because you haven't been charging it.
There are options using battery combiners that bypass the switch when a charge current is available but you just added cost and complication.
With a trailer, a second bank is usually not needed anyway. You always have the truck battery available in a pinch. Simply plug in the truck while it's running and it should give you enough juice to get the slide in (if the plug doesn't move enough juice, a set of jumper cables certainly will).
