What are the best batteries and where to buy them?

Thanks all. I'm going to take the golf cart advise and check out Costco, as well as look up the recommended starting battery.

Have a fabulous and safe new year. You folks are Awesome!!!

Mike G.

A "token" house battery if that is all that you need, still has to be able to start your built-in generator though. I don't know what that takes.

for starting MY Cumins
i use AutoZone gold tops, (2) of them, gold tops have a 3yr free exhange, and 4yrs more of prorate, and plenty of cranking power

for house, i have run various batteries over the years, and settled on 12 AGM telco/server batteries giving me the best life,
Golf cart 6v pairs, work very well for most users

Bang for buck, a couple 6v golf cart from Costco.
Starting,......what ever the diesel requires, and probably from the same place....or WM

Deka or Trojan would be two of my top choices, particularly for deep cycle batteries.
Batteries are really only made by a handful of companies, probably around 5 in the country. They just re-brand them for everyone else.
I agree with using 6v golf cart batteries for your house bank. 2 is a good start, 4 is better if you camp without hook ups much. As for starting, find out how many CCA Cummins recommends for that engine. Then get at least that many if not more in whatever battery will fit the space.
Cummins does not have a "G" in it.

Walmart is always open and has decent batteries. There are everywhere if your traveling. Kind of hard to get a golf cart shop to open up on Sunday or at 5 am when your loaded and ready to head out.
Please remember I am only right half the time.

For house batteries it depends a good bit on how you intend to use the motorhome. If you need something more than a token battery, often the most cost effective in terms of capacity and longevity for the money are pairs of 6V golf cart batteries. It pays to shop around for them a bit. Sam's Club and Costco in many places have them for around $90 apiece, but sometimes local golf cart shops may have better quality or higher capacity batteries for about the same price...and sometimes the golf cart shops are much more expensive.

If your time camping will be generally spent hooked up to shore power or running the generator or on the road, you don't need much of a house battery. A single marine/RV battery is probably the least expensive. All it needs to do is keep things running while you run into a restaurant or hook up at the campground.