Will these old batteries help my electrical system at all?

[Suicide Bobb 5,000+ posts]

I have two old batteries, one sits at 11v and the other at 9.5. If I were to hook these up in my car (either one, or both), would it help stabilize my electrical system? My lights dim a ton when the sub hits, so I'm hoping to at least help it out a little if possible. I don't know enough about batteries, so I'm sorry if this is a total noob question.

-Dylan

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[outsideshot23 10+ year member]

If its at 9.5 no.. That means it is fully discharged... hard to say on the other one.. it will help short term but it could shorten the life of your other one.. hard to say without more info

 

[Suicide Bobb 5,000+ posts]

If its at 9.5 no.. That means it is fully discharged... hard to say on the other one.. it will help short term but it could shorten the life of your other one.. hard to say without more info

Oh...shoot. What do you need to know about it? It is an industrial battery if I remember right.

 

[outsideshot23 10+ year member]

system your running, wattage, batt in your car (ah), batt your going to put in, alt amperage.. pretty much everything about your electrical.. if your running 10kw one old batt wont help.. lol..

 

[audioholic 5,000+ posts]

If that's the voltage they rest at after being charged, throw them both away (errr... dispose of them properly). Even the better one of the two is no where near the 12.8 volts you want. Both batts will only serve to add strain to your electrical system, as they will offer virtually no beneficial power storage, and will be significant points of resistance in the circuit.

 

[iamamp3pimp 5,000+ posts]

basically what he is saying is take em to autozone and get them charged (unless you have a charger, then you can do it yourself)

let em sit for a day or so and test them.

if they sit at or above 12.6 then youre good.....if they drop back to what they are at now, it will hurt more than it helps./

 

[Suicide Bobb 5,000+ posts]

system your running, wattage, batt in your car (ah), batt your going to put in, alt amperage.. pretty much everything about your electrical.. if your running 10kw one old batt wont help.. lol..

Here's what I know...

1250wrms amp

normal car battery

stock alternator (1996 Saab 900se) not sure how many amps

no big 3

4 ga power and ground, 100a fuse

 

[Suicide Bobb 5,000+ posts]

basically what he is saying is take em to autozone and get them charged (unless you have a charger, then you can do it yourself)
let em sit for a day or so and test them.

if they sit at or above 12.6 then youre good.....if they drop back to what they are at now, it will hurt more than it helps./

Thanks, I'll go ahead and try that out.

-Dylan