Second battery
Our camper has only room for one group 24 battery. A few years ago I added wiring and a multipoint switch for an additional battery to go ahead of the rear wheel well but have not used it until now. ...
Forum Discussion
rwiegand wrote:
Not knowing any better, I've run mismatched batteries hooked together in parallel for decades now. My truck currently has one that's about four years old and one that's about 7. On average I get the same 5-7 year lifetime out of the ones hooked together in parallel as with other similar batteries used as singles in my other vehicles. I get the theoretical argument, but I suspect that if there's a detrimental effect it is unmeasurably small.
I have had the exact opposite experience. We had a diesel Cadillac back in the early 90's for a while with dual batteries, and we were constantly chasing bad batteries back and forth. One would go bad, then the other one would go bad within a month, then the first new one would go bad within a month, then the second new one would go bad within a month. Ruined 5 batteries until we installed two brand new batteries at the same time. Then no issues after that.
Have the same problem with the tractors that have two batteries. Just chasing bad batteries back and forth until you replace both at once.
