Best Battery For my 3500 6.7 Cummins?

[ATA]

In last couple days when I start the truck it shows the battery is low(the red battery light is on), I need to drive for a while to be charged and light off, So I am guessing buying two batteries is around the corner. Do you guys have any idea on which brands and batteries are best for my truck?

I taught the RV will charge and help truck batteries but it sims not to be the case and you need to buy a battery tender to do so, Also if you have any idea about that Ill be thankful. My 3500 have the camera on it always and only sometimes if I have very heavy hauling I borrowing it for business, otherwise it is only for camper which I use every week for overnight fishing.

[detroit1]

If you have owned it since new, get the same type /size that's already in it.