How to pair up batterys

[jasonjc]

I just got 6 new 6TL's for 3 of my truck. The place I got them from tested all 6 and said the CCA was 835 - 960 or 860-935?? Oh well can't remeber which. But here's the ?? do I put the 2 hottest one's together or the strongest and weakest. I want these too last alooooong time.

 

[Crazyguyla]

I'll take a stab at it. Pair them up by CCA and by the conditions. strong with strong so they charge at an equal rate. Having a strong and weak battery will cause the batteries to charge unevenly cutting battery life. Try to keep the batteries fully charged with regular charging or a battery maintainer.

 

[houdel]

Marcus is correct. Match the battery pair capacities as close as you can. Mismatching batteries - for example a new, strong 6TL with an old, tired 6TL - will shorten the life of both batteries. The stronger battery will act as a "sink" and try to pull more charging current than the weak battery can pass, and the weak battery will act like a resistor and limit the charging current. The weak battery will be overcharged, the strong battery will be undercharged, and the life of both will be shorter than if then had been properly paired. However, in your case all your batteries are new, so there should not be a significant difference in the performance of the individual batteries. I would suggest that the "underachievers" you have were not fully charged before testing.