Adding Battery Capacity

[GallopingGrandpa]

I’m a new member and have really enjoyed reading a few threads. I am going to make several upgrades to my rig and pretty sure I am going to need some advice.
I purchased a 2023 Hideout 22MLS. Has all the usual stuff the new ones come with. It came with one 100ah 12v Lithium battery. I would like to add a lead acid battery to it to increase capacity. I can’t find any information on the best way to wire it into the system. Can anybody help me possibly with a wiring diagram?

[chuckster57]

I would not mix battery types as they have different charging profiles. I would add an additional lithium battery.

If you’re using 12V battery’s hook the positives together and the negatives together (Parallel) and then attach the trailer leads to opposite batteries.

[GallopingGrandpa]

Thanks chuckster57...There is a number of opinions around this issue of mixing "types" of batteries and different charging profiles are top of the list. I think it is all in how you wire them in parallel. What I am looking for is which battery should the neg come from and the pos come from.

[mikec557]

Originally Posted by GallopingGrandpa

Thanks chuckster57...There is a number of opinions around this issue of mixing "types" of batteries and different charging profiles are top of the list. I think it is all in how you wire them in parallel. What I am looking for is which battery should the neg come from and the pos come from.

GG, if you mix battery types you'll likely burn up one or the other battery. That will cost you more money in the long run to buy another "second battery".

But to answer your question, you need to connect the trailer positive wire (probably red) to the positive of either of the two batteries. Whichever battery you choose, do NOT connect the trailer ground to that battery. Connect the trailer ground to the "other" battery. So, the trailer has two cables, one goes to each battery (assuming 12v batteries in parallel).

[sourdough]

Originally Posted by GallopingGrandpa

Thanks chuckster57...There is a number of opinions around this issue of mixing "types" of batteries and different charging profiles are top of the list. I think it is all in how you wire them in parallel. What I am looking for is which battery should the neg come from and the pos come from.

Don't know where the differing opinions come from for mixing a LA battery with a lithium as your DC power source. If you want your battery system to function properly, charge properly and last as long as possible you won't mix lithium with lead acid. Just buy two identical batteries and get on down the road...best option, longest lasting, least problems. Think about it; you can put a 35" diameter tire on one side of your vehicle and another that is a 29" diameter...it will work....for a short while, and all the time tearing up all kinds of other equipment. Go at it the right way IMO.

[GallopingGrandpa]

Guys .... Thanks for the help. I am putting a link to a YouTube vid for you to watch and give me your opinion.

http://www.youtube.com/watch?v=tAuPfgZgXec&t=1153s

[chuckster57]

Looks like he doesn’t do 50/50 and he’s using LiPo4.

If you’re only using 2 batteries, I would still use the same types.

[travelin texans]

The other "not recommended" is mix new with old batteries which you've said you have a lithium installed already & wanting add another "new" battery of a totally different type, none of which sounds like a good plan.
Either buy another lithium, which will be mixing new with old, or buy 2 new true deep cycle FLA batteries, which is probably a lot cheaper than another lithium.

[CWtheMan]

https://www.keystonerv.com/owners-ho...ctrical-system

[GallopingGrandpa]

Been New Years busy!!! Thanks to all of you for the advice. I think I will stay with keeping my battery's separate. Seems like the safest way to go.