Two batteries in 2012 F-350?

I suggest you find a new dealer to work on your truck.

If you place a new battery in parallel with a older weaker one, the new one will assume the chemistry of the old new fairly quickly. That is why one should replace both in such installations.

If it has only been a short time I would get the second old one replaced ASP.

Ford dealer should have known this!

same rule for travel trailers, if the batteries are weak time to replace them both.

LowRyter wrote:
same rule for travel trailers, if the batteries are weak time to replace them both.

Same for golf carts that have multiple batteries as well.

For those who are interested, after returning from vacation and by truck in the shop for 8 days, the problem turned out to be a faulty body control module that would intermittantly stay open and cause a battery drain.

Hopefully this will correct the problem once and for all.

because of the wife's heart condition I bought 2 new batteries before we left for Az last Oct. Not 4 years old yet but felt better with new. Most of my driving life 4 years was about a battery's life or after 4 winters, same deal.

Better to be safe than sorry. Glad the OP is doing the same.

chevman

Well, I think this thread got dredged up by mistake, but I have a diesel battery anecdote to tell you about also.

When I was a kid we had an 1980 Cadillac with the 5.7L diesel. Real cream puff, low miles. Ultimately the folks ended up in a wreck with it about a year after they bought it so we never got the chance to experience the joy of the 5.7L diesel engine, but back to the battery story...

After the wreck we found a new front clip and fixed it up and got it driving again. But we were always chasing problems with one battery or the other going bad. We'd find one battery bad, and replace it with new. Then the other one would die, and we'd replace that one with new. Then the first new one would die, so we'd put another new battery in. Chased it back and forth about 5 times before we took both batteries in at once and got them replaced under warranty. Once we put two new identical batteries in, the problems stopped.

I recently had a 750 amp read on secondary battery and a 440 amp read on the primary battery. I chose to only replace one at Ford dealership that was still under the Motorcraft Tough Max 100 month limited warranty. This is my 7th battery in 6 years.

I made the decision when they both need replacing I will go to a better battery brand. I've been chasing full warranty and limited warranty on the Motorcraft brand every 2 years.

Vvvv1010 wrote:
I recently had a 750 amp read on secondary battery and a 440 amp read on the primary battery. I chose to only replace one at Ford dealership that was still under the Motorcraft Tough Max 100 month limited warranty. This is my 7th battery in 6 years.

I made the decision when they both need replacing I will go to a better battery brand. I've been chasing full warranty and limited warranty on the Motorcraft brand every 2 years.

Wow, Texas must be harder on batteries than Pennsylvania winters. I have the exact same truck with the original batteries. (Knock on Wood) :? You might want to have the charging system tested.

Lynnmor wrote:

Vvvv1010 wrote:
I recently had a 750 amp read on secondary battery and a 440 amp read on the primary battery. I chose to only replace one at Ford dealership that was still under the Motorcraft Tough Max 100 month limited warranty. This is my 7th battery in 6 years.

I made the decision when they both need replacing I will go to a better battery brand. I've been chasing full warranty and limited warranty on the Motorcraft brand every 2 years.

Wow, Texas must be harder on batteries than Pennsylvania winters. I have the exact same truck with the original batteries. (Knock on Wood) :? You might want to have the charging system tested.

Actually extreme heat is worse on batteries than cold. But cold is hard on them too. Another reason a temperate climate is good for.....about everything.
Having lived in most of the different N American climates, I've noticed that here on the wet side of the Cascades, appears to be the best overall climate for vehicles and their components I've experienced.
Batteries last longer, very few extreme hot days and no cold days. Tires last longer, cloudy= less UV damage and predominantly wet pavement = better tread wear from lower friction coefficients and generally lighter on the throttle due to slippery roads.
Paint/dash/interior lasts longer, less uv damage and even though it's wet a good portion of the year, I think this area rivals dry southwest climates for no rust. I attribute it to the constant fresh water rinse of the undercarriage 6mo a year. Prevents any build up from trapping moisture long term as well as any corrosive road salt/mag/calcium gets thoroughly washed off directly.