First multiple battery setup help

[d luv 0]

I will be running two batteries for the first time and have some questions. I have an energizer battery under the hood, and a yellow top for the truck. My question is will these two be ok ran together? I thought someone told me the batteries must be the same, but I could be mistaken. Thank you for the input.

[jonbearsmt 919]

they willbe fine, make sure they are both fully charged

[An-i-no 86]

I will be running two batteries for the first time and have some questions. I have an energizer battery under the hood, and a yellow top for the truck. My question is will these two be ok ran together? I thought someone told me the batteries must be the same, but I could be mistaken. Thank you for the input.

In a perfect world, the batteries would be the same. The reason for this is that batteries rest at different voltages and the one with the higher resting voltage will charge the other one until they equal out. This can cause the one with the higher resting voltage to die sooner especially if the voltages are way off (like one at 12.2 and another at 12.9).

The good part is...that most people don't leave their cars off long enough for the charges to fully equalize (like if you drive it every day, you should be good to go) but it can still shorten the life of your batteries. If you DON'T drive the car every day I would NOT recommend running two different batteries because one will go bad.

You can use a battery isolator but I'm not sure how reliable those are. Just google "battery isolator" and read up.

Oh and try not to mix Wet Cell and Dry cell because they usually have different resting voltages and wet cell batteries do NOT like to be deeply discharged and charged back up. They will go bad very fast. And then, when the wet cell goes bad, the dry cell will try to charge it until it dies too and you just lost 2 batteries.

EDIT: and Bigjon ninja's me with the quick answer lol

Edited May 8, 2012 by An-i-no

[jonbearsmt 919]

all good things your mentioned.

battery isolators are useless unless you plan to play your stereo with the car off.... a HUGE no no in my book anyhow.