do i need an isolator?

[ultimate157 5,000+ posts]

if you read lots of install stuff for deep cycles on boats they recommend matching batteries not using old/new together.

Thats because if you use a really old battery with a new one, the old one will partially drain the brand new battery. The used battery has a lower resting voltage which will drain from the battery with a higher resting voltage.

 

[gotparts90 10+ year member]

exactly and batteries that have a different resting voltage should not be stored connected. If you have identical batteries linked no problems they act as one. If the voltage is off by a little it will flow ever so slow, and that problem can be isolated

 

[romans535 10+ year member]

O.K. this thread is really good, I myself have an isolator for the fact that I like listening to my sounds while the car is of for long periods of time. I have 2 different batteries both good and new, how can I know when its time to turn on my car before one of the batteries dies, would my voltage be an indicator(like if it starts dropping below a certain voltage).

 

[mil81 10+ year member]

exactly and batteries that have a different resting voltage should not be stored connected. If you have identical batteries linked no problems they act as one. If the voltage is off by a little it will flow ever so slow, and that problem can be isolated

I think he's saying when the older battery starts to die, it will draw down the new battery, and you won't get the effect of the dual batteries, or the new battery for that matter. But as long as the old battery still holds a descent charge, there won't be any problem with the system at all.

O.K. this thread is really good, I myself have an isolator for the fact that I like listening to my sounds while the car is of for long periods of time. I have 2 different batteries both good and new, how can I know when its time to turn on my car before one of the batteries dies, would my voltage be an indicator(like if it starts dropping below a certain voltage).

The voltage of your battery will stay right close to 12V even when it is dead, and failing. It's the storage capacity that is failing. Personally, without seeing problems with the performance, I don't know how to tell if a battery is failing. I know you can get them tested out. Lots of your auto parts stores will do it.

Edit: My dodge, as well as almost any Diesel truck come stock with two batteries. They don't have an isolator installed. They are not necessary, just a nice precaution, to make sure you won't be stuck needing a jump start.

Marine recomendations are a lot pickier than automotive situations, since it gets a little scarier when you're stuck in the middle of the ocean (or big lake for that matter) with no power to start the boat. You'd be a very large sitting duck, waiting for the oncoming storm.

 

[Korn4Life 5,000+ posts]

I use one and im only getting a .02 voltage drop... I would get one

 

[romans535 10+ year member]

I think he's saying when the older battery starts to die, it will draw down the new battery, and you won't get the effect of the dual batteries, or the new battery for that matter. But as long as the old battery still holds a descent charge, there won't be any problem with the system at all.



The voltage of your battery will stay right close to 12V even when it is dead, and failing. It's the storage capacity that is failing. Personally, without seeing problems with the performance, I don't know how to tell if a battery is failing. I know you can get them tested out. Lots of your auto parts stores will do it.

When I'm playing music with the car on, I periodically turn the car on just in case the batteries are close to getting drained. I heard that with the isolator you could play your music loud for hours, I don't want to chance it cause with the yellow tops recharching takes a long time.

 

[mil81 10+ year member]

When I'm playing music with the car on, I periodically turn the car on just in case the batteries are close to getting drained. I heard that with the isolator you could play your music loud for hours, I don't want to chance it cause with the yellow tops recharching takes a long time.

With an isolator, you select which battery you want to run. In the case where you want to crank the system at a party...You select the rear batteries, and the front battery is uneffected. You can crank the system for as long as your rear batteries will live, then switch back to the front battery to start the car and re-charge the rear batteries.

If you do crank the system for long periods of time with the car off, it would be a great idea to put an isolator in. Is it necessary, no. But a good idea. Like I said before, it will save you sitting there, calling around for a jump.

 

[shpatb 10+ year member]

back to the drive in movie thing, its just because stingers are badass batteries...

 

[Harleyfx69 10+ year member]

Edit: My dodge, as well as almost any Diesel truck come stock with two batteries. They don't have an isolator installed. They are not necessary, just a nice precaution, to make sure you won't be stuck needing a jump start.

your dodge cummins diesel comes with two batteries for a reason ..

Not just in case one goes bad you have a spare ..

engine = very high compression, requiring a lot of cranking amps to power your starter ..

 

[romans535 10+ year member]

With an isolator, you select which battery you want to run. In the case where you want to crank the system at a party...You select the rear batteries, and the front battery is uneffected. You can crank the system for as long as your rear batteries will live, then switch back to the front battery to start the car and re-charge the rear batteries.
If you do crank the system for long periods of time with the car off, it would be a great idea to put an isolator in. Is it necessary, no. But a good idea. Like I said before, it will save you sitting there, calling around for a jump.

HEY, thanks for the info, does makes sense. //content.invisioncic.com/y282845/emoticons/handclap.gif.0c301076f534e244f0460706894f19e0.gif:handclap:

 

[mil81 10+ year member]

HEY, thanks for the info, does makes sense. //content.invisioncic.com/y282845/emoticons/handclap.gif.0c301076f534e244f0460706894f19e0.gif:handclap:

Thank you very much.

your dodge cummins diesel comes with two batteries for a reason ..
Not just in case one goes bad you have a spare ..

engine = very high compression, requiring a lot of cranking amps to power your starter ..

Thanks. I know WHY the truck has two batteries, but the fact remains that it has two batteries without an isolator. Proving that an isolator is not necessary.

 

[MTs390 10+ year member]

thanks for the information guys. i appreciate all the help

 

[DidUHearThat? 10+ year member]

$44.50

http://www.darvex.com/miva/merchant.mvc?Screen=PROD&Product_Code=SGP32&Product_Count=1

 

[romans535 10+ year member]

$44.50

http://www.darvex.com/miva/merchant.mvc?Screen=PROD&Product_Code=SGP32&Product_Count=1

Dam I guess I kind of got burned, I paid 70 for mine. And thats after bargaining with them. //content.invisioncic.com/y282845/emoticons/mad.gif.c18f003ab0ef8a0d9c27ca78d77a6392.gif