Absolute best way to wire 2+ batteries together

[ultimate157 5,000+ posts]

Yes its supposed to help maintain the charge of the starter batt. but i never listen with the key on and car off. he told me that if i didnt have an isolator between them that they would eventually short eachother out. i was like wtf ever dude im out. the way i see it is my dads diesel tuck has 2 batts and NO isolator so how could that be any diff?

Oh and another thing. would mixing batts, like brands and sizes hurt anything? i got conned into buying 2 stinger batts, and im not paying that price again. so would it hurt?

It doesn't help maintain it. It completely disconnects the battery from the circuit.

Mixing brands or sizes won't matter, but mixing TYPES of batteries will. EG: Wet cell, dry cell, AGM, etc.

 

[sweenster123 10+ year member]

so lets say i throw a couple a optimas on my stingers it wont hurt?

It doesn't help maintain it. It completely disconnects the battery from the circuit.
Mixing brands or sizes won't matter, but mixing TYPES of batteries will. EG: Wet cell, dry cell, AGM, etc.

 

[smoka 10+ year member]

It doesn't help maintain it. It completely disconnects the battery from the circuit.
Mixing brands or sizes won't matter, but mixing TYPES of batteries will. EG: Wet cell, dry cell, AGM, etc.

Wrong, if you have two batts without isolators. One bad batt will most likely kill the other one. Its recommended that if you don't use an isolator, then you should have the exact same batts with the same datecodes.

Otherwise if you wan't to mix batts you should isolate both to keep them from draining/charging each other if one goes bad.

Most people only isolate the rear batt, but really all batts should be isolated.

 

[Team MAF 10+ year member]

IDK about anybody using isolaters. I thought you want the batteries on a bank I.E AS ONE, so that way everything is being used equally "across"

Yea kids are pretty shitty they wont admit a beating or defeat. Kids always rag me saying oh THATS TOO LOUD MAN you cant hear the words or anything, im like HAH i dont listen to it that loud all the time dousche or id be deaf like your grandpa.

 

[smoka 10+ year member]

IDK about anybody using isolaters. I thought you want the batteries on a bank I.E AS ONE, so that way everything is being used equally "across"

You can do that as long as they are all the same size batt and bought at the same time.

 

[bulldoggg 10+ year member]

IDK about anybody using isolaters. I thought you want the batteries on a bank I.E AS ONE, so that way everything is being used equally "across"
Yea kids are pretty shitty they wont admit a beating or defeat. Kids always rag me saying oh THATS TOO LOUD MAN you cant hear the words or anything, im like HAH i dont listen to it that loud all the time dousche or id be deaf like your grandpa.

I use a 200 amp relay to keep my batts isolated from each other. The reason why I use it is because I have different size batts and I want them to last as long as possible. When the car is on the 2 batts are linked and are basically one big battery. Its only when the car is off and they're not being charged that they're isolated. Many people run 2 or more batts without a isolator and it works fine. The only downfall is that your batts will wear out a little quicker than if you have them isolated. For some people its not worth it to have a isolator. I guess its a matter of opinion. I killed a couple of yellow tops in about a year without a isolator which I felt was a little quick for me. But I've also heard of other peoples batterys lasting way longer without a isolator so who knows.... But nobody is gonna "short out" they're batts or hurt anything by not having one. Worst case your batts won't last as long...

 

[Team MAF 10+ year member]

I use a 200 amp relay to keep my batts isolated from each other. The reason why I use it is because I have different size batts and I want them to last as long as possible. When the car is on the 2 batts are linked and are basically one big battery. Its only when the car is off and they're not being charged that they're isolated. Many people run 2 or more batts without a isolator and it works fine. The only downfall is that your batts will wear out a little quicker than if you have them isolated. For some people its not worth it to have a isolator. I guess its a matter of opinion. I killed a couple of yellow tops in about a year without a isolator which I felt was a little quick for me. But I've also heard of other peoples batterys lasting way longer without a isolator so who knows.... But nobody is gonna "short out" they're batts or hurt anything by not having one. Worst case your batts won't last as long...

Sorry to tell you, but everyone ive been around almost fired //content.invisioncic.com/y282845/emoticons/verymad.gif.3f39c5c2fd57527b671fad3efdfac756.gif on me for mentioning the brand"optima" . I know several people that have ran through 2-3 optimas replacing them everytime one blows out shorter than their life time would recommended. I thouht they were deep cycle batteries? Surely dont seem like it if they blow out that **** quick.

 

[bulldoggg 10+ year member]

thats why i have stinger batts now...optimas arent reliable but i still believe that my stinger batts would not last quite as long if i didnt isolate them from each other.

 

[loopkiller 10+ year member]

Any brand of battery is easy to kill if it is not maintained or installed properly. Yes the Optima brand is well known for early deaths due to the extremely thin plates. But most people are not aware that other brands of batteries are made with the exact same technologies.

If you do not keep your battery fully charged, it will shorten the life. If you overcharge your battery, it will shorten the life. If you over-discharge your battery, it will shorten the life. If you mix batteries in a single circuit, it will shorten the life.

Unless you have exactly matching batteries, same brand, model, age, etc, you are risking early failure. Good batteries that might last you 10 years with proper use might only last 5 years. Now some people would say that 5 years is a good long time from a battery, but it is still half of what you could have gotten from them.

 

[Team MAF 10+ year member]

Any brand of battery is easy to kill if it is not maintained or installed properly. Yes the Optima brand is well known for early deaths due to the extremely thin plates. But most people are not aware that other brands of batteries are made with the exact same technologies.
If you do not keep your battery fully charged, it will shorten the life. If you overcharge your battery, it will shorten the life. If you over-discharge your battery, it will shorten the life. If you mix batteries in a single circuit, it will shorten the life.

Unless you have exactly matching batteries, same brand, model, age, etc, you are risking early failure. Good batteries that might last you 10 years with proper use might only last 5 years. Now some people would say that 5 years is a good long time from a battery, but it is still half of what you could have gotten from them.

Heh //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif but arent car audio batts(branded ) or large specially made batteries ready to beat up hard, charge/discharge frequently? If im paying the price to murder the hell out of a battery because thats what its made for and itll at least keep up hard for 5 years...thats kool and the gang with me.

Versus trying to run store bought..optima or other standard "economy" batteries

 

[gotparts90 10+ year member]

Wrong, if you have two batts without isolators. One bad batt will most likely kill the other one. Its recommended that if you don't use an isolator, then you should have the exact same batts with the same datecodes.
Otherwise if you wan't to mix batts you should isolate both to keep them from draining/charging each other if one goes bad.

Most people only isolate the rear batt, but really all batts should be isolated.

yep thats what the engineers that I used to work with said too. they are the guys that designed the optima batteries from the colorado branch of JCI.