Adding a 2nd battery....

[myjaja 10+ year member]

Ok, I still don't know if I should add the relay or not. My brother keeps telling me that I have to because my factory alty isn't strong enough to charge both batteries. Is this true?

 

[Newport 10+ year member]

sorry for being a noob.... i've been wanting to do this for a while. all i have to do is take my 0/1 pos from the front and put it on neg of second battery. then take the pos from second batt to the dist block, and neg of second batt goes to frame? that can't be right.... someone wanna straighten this up for me?

if you do that than you would have 24 volts. like batteries in a flashlight

 

[casper97ta 10+ year member]

Ok, I still don't know if I should add it or not. My brother keeps telling me that I have to because my factory alty isn't strong enough charge both batteries. Is this true?

It will put a little more strain on your stock alt. I always recommend getting a HO alt first and then more batteries. If you have any doubt you should go with a new alt. first. It is a better investment and will do more to help you than just adding batteries.

if you do that than you would have 24 volts. like batteries in a flashlight

^^^^And to that mess, what the **** are you talking about?? You really shouldnt give anybody any advice ever. That has to be one of the stupidest things I've ever heard.

 

[myjaja 10+ year member]

It will put a little more strain on your stock alt. I always recommend getting a HO alt first and then more batteries. If you have any doubt you should go with a new alt. first. It is a better investment and will do more to help you than just adding batteries.

The thing is, I got the battery for free from my brother. It'll be a waste not to use it. I really don't have the extra cash to upgrade my alty. So can I mess up anything just having the second battery connected in parallel without the relay?

thanks

 

[myjaja 10+ year member]

if you do that than you would have 24 volts. like batteries in a flashlight

wtf? lol

 

[casper97ta 10+ year member]

No you wont hurt anything. If you already have the battery go right ahead and use it. It will help. Just run + to + and you can either ground the second battery to a chassis ground, or do a run from the - on your under hood battery.

 

[Newport 10+ year member]

sorry for being a noob.... i've been wanting to do this for a while. all i have to do is take my 0/1 pos from the front and put it on neg of second battery. then take the pos from second batt to the dist block, and neg of second batt goes to frame? that can't be right.... someone wanna straighten this up for me?

When connecting your batteries in Series you are doubling the voltage

12 + 12 = 24

 

[bonesninja 5,000+ posts]

heres a bit of advice...if you do use both batts, and your alt is already having a hard time keeping up...make sure that you let your alt charge the batts with your stereo turned off after you've bumped for considerable amounts of time. If you constantly bump and don't want to ride with the stereo off , then invest in a h.o. alt...or a good battery charger.

I always keep a good battery charger on hand anyways.

 

[SPL140.2 5,000+ posts]

It will put a little more strain on your stock alt. I always recommend getting a HO alt first and then more batteries.

good advice //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[bottom3 10+ year member]

If you run +- and -+ it will be closer to 29 volts than 24. Also, don't put an usealed battery in the vehicle compartment.

 

[joetama 5,000+ posts]

heres a bit of advice...if you do use both batts, and your alt is already having a hard time keeping up...make sure that you let your alt charge the batts with your stereo turned off after you've bumped for considerable amounts of time. If you constantly bump and don't want to ride with the stereo off , then invest in a h.o. alt...or a good battery charger.
I always keep a good battery charger on hand anyways.

I do agree with this. But unless he is really pulling a lot of amperage on his system a second battery will not cause a problem.

Also, putting a relay in "because your alt won't keep up" is a bad idea. Think about it like this. Battery one is charging and is at 14 volts battery two is cut off from the relay and is at 10 volts (really low because you don't know the voltage and it hasn't been charging). You now close the relay connecting the second battery. The first thing that is going to happen is the two batteries are going to stabilize with each other (since there is more current outflow and inflow with the battery than with the alternator). This could have the potential for pulling literally 500+ amps. This not only will cause heat in the cable and fuses but also in the batteries. Then once the voltage stabilizes around 12 volts the alternator has the job of charging both batteries from 12 volts. This will max out your alternator anyway. And will actually keep your alternator pushing its maximum output power for a longer period than if you were to just charge the two batteries together. It is much better to have the alternator push a common load at 13 volts than for it to have to push a common load at 12 volts... After factoring the surge from the batteries and the extra heat created I would defiantly not install a relay...

 

[connersdad19 10+ year member]

i am going to be adding a battery and was looking at an isolator..just to be safe in case i dont drive my car for a couple of days....i was told to get one if you wont be driving the car for like a couple days...but i just want one to be safe...good or bad idea?

 

[joetama 5,000+ posts]

Well... An Isolator literally isolates the two batteries away from each other. So, you have one for your car power and one for your stereo power...

IMO this sort of voids the whole point of running two batteries. If you have never had a problem with your car battery running dead with one battery then you shouldn't have this problem with two batteries...

 

[connersdad19 10+ year member]

well i have seen on forums where people say they fight over voltage or some crap...true or not? because if i can save money in not getting an isolator then that will help lol

 

[joetama 5,000+ posts]

I would say 90% of people don't use an isolator and don't have a single problem.

Batteries don't fight. What an isolator would be good for is if you have something that is a slow drain (like an amplifier that doesn't shut completely off when the remote is turned off)...