slow to start when cranking

How many batt. does truck have,ck. old ones 1st with batt. load ck. tool then replace bad batt.

 

I always replace all four at the same time. It is possible that the two you didn't replace are getting ready to bite the dust.

 

Yep, four at a time. One bad battery will tank the other three. I'd recommend east penn dekas.

 

Yeah one older bad battery will ruin 3 other brand new ones in short order. Always replace all 4 at a time or you will be buying batteries every few months.

 

Yeah late to the game I know lol

 

Providing a consensus to always buy four at a time.

When I bought mine the guy gave me a one year warranty. Then an additional year pro rated. I'll take the truck back to him in 11 months from purchase so he can test all four. I'd have no problem replacing one bad battery if it's bad and under warranty to get my money's worth. The other 3 batteries at say 80-90% would quickly bring the new one to their range, and hopefully provide me 3-5 good years of service.

A tip for those that like to "cheat the system" a bit. Usually places aren't going to warranty past a year in a commercial application. I of course figured this out after the fact.

I'd recommend going to two different stores and buying a pair at each store. They will assume when you say they are for your truck you just a have a big diesel pickup with 2 batteries total. If you need to replace 2 1/2 years down the road, you should still be under that 3 year warranty normally offered on batteries. Just a tip I'm going to throw out there.

 

Keep accessories usage to a minimum or even zero without the truck running. Keep the battery box and batteries clean and make sure are the connections are clean and tight. They will last 4 or 5 years like that.

A battery salesman also told me people farther north in colder climes get longer battery life than people further south in harsher heat. You would think the exact opposite that cold kills or shortens battery life but he said industry data proved otherwise. Places like AZ have shorter battery life than MI.