New batts??

[Akslowroller]

So my local stereo shop tells me I need all new batteries when using them together. For example, if I were running only one spare batt it would be ok that it was a used battery. However when doing multiple batteries they say you must use all new batteries so they don't draw down from one another?? I'm confused because as far as I know no two batteries are going to have the exact same voltage. So what is the difference if they are new as long as they all are good?

[MIKE-2U]

Must be talking about agm batteries. Yes its best to use all agm prefreably all the same brand.

[Akslowroller]

Must be talking about agm batteries. Yes its best to use all agm prefreably all the same brand.

Well I have three yellow top optima batteries and wanted to use them and they told me I couldnt unless they were new

[MIKE-2U]

I don't think thats correct. The way i have been told and understand it is if they are all the same kind its fine. But yours are all the same kind, and same brand so it should be fine because the chemistry in the batteries is the same. Maybe someone can chip in and agree or correct me but i believe your ok.

[imnew59585]

i think you are correct, ive been going threw these forms and from what ive read i can say that you should be good to go

[Lbox88]

Same brand does not matter, same makeup does have a small bearing. The killer is Resting voltage. Say you have 2 optima yellows, one has a resting voltage of 11.7 while the other sits nice and happy at 13.1. The bad batt that sits down at 11 will drag power off of the higher battery until they reach a point of equilibrium. I have a Kinetic hc2400 in the back and a diehard gold advanced agm up front, both rest happy at 13.1 so there is no problem. Hope this helps a little.

[imnew59585]

yeah i was thinking about the voltage too but i forgot to put it in, so like he said make sure they are charged and have around the same voltage

[andale927]

So my local stereo shop tells me I need all new batteries when using them together. For example, if I were running only one spare batt it would be ok that it was a used battery. However when doing multiple batteries they say you must use all new batteries so they don't draw down from one another?? I'm confused because as far as I know no two batteries are going to have the exact same voltage. So what is the difference if they are new as long as they all are good?

IT IS TRUE. But don't worry about it. And I hate when people think it is possible for a battery to rest at 13.1v. Any battery that reads 13.1 volts obviously still has a float charge from being charged with an alternator. Highest open circuit voltage possible is 12.80 volts after sitting for 24 hours and usually 12.7+ indicates a full charge

[grim83]

:facepalm: if you went to a shop and asked if they could install a pair of door speakers you already had (didnt buy from them) and they said no it must be a new purchase would you be fucking on here asking this. the hell is wrong with people cant see past a little slimeball sales scheme these days. And for simplicity sake yes as long as all your batterys are in working order and the same shit then you can run them new or used fuck do you people need to be bottle fed

[Lbox88]

IT IS TRUE. But don't worry about it. And I hate when people think it is possible for a battery to rest at 13.1v. Any battery that reads 13.1 volts obviously still has a float charge from being charged with an alternator. Highest open circuit voltage possible is 12.80 volts after sitting for 24 hours and usually 12.7+ indicates a full charge