Isolator Suggestions?

[silenkiller 10+ year member]

Trying to figure out what the best isolator would be for my 4kw setup. I'm looking to minimize the voltage drop that I've heard occurs with them. Trying to separate my starting battery and a C n D batt.

Any suggestions based on experience guys?

Do I need something such as this?

http://www.hifisoundconnection.com/Shop/Control/Product/fp/vpid/7016927/vpcsid/0/SFV/30046

Click to read more...

 

[ejschultz 10+ year member]

That isolator is a relay/solenoid type isolator. There will not be a voltage drop with that type of isolator. Go to http://www.bcae1.com/battiso.htm to learn about the 2 types of battery isolators commonly used in car audio and see which one you'd prefer. I used to have the diode type isolator. I never used it because I couldn't find a place to put it. They're rather large, but they do last a lot longer and do completely separate the front and rear battery when the car is off and on. They charge separately with that one. With the solenoid isolator, the batteries are separate with the car off, but charge together with the car on. This will shorten the life of the batteries unless both batteries are the same. EDIT: Isolators will increase the life of a battery vs. not having one.

 

[silenkiller 10+ year member]

Sigh. So many people run extra batts without this. Makes me wonder if its really necessary.

 

[silenkiller 10+ year member]

All of the isolator setups that are diode only go up to a max of 200 amps on the alternator side. My alt will be over 250 amp at full speed. Sigh this is difficult.

 

[ejschultz 10+ year member]

If you want to do it right, I'd recommend getting 2 of the isolators you're looking at, a couple of switches and doing it the way it's shown on bcae1.com. When I ran mine, I deep cycled my battery in the trunk. I never had it wired up front. I decided I was tired of pulling a 70 lb battery out of the trunk every time I wanted to charge it so I decided to wire it up front. When I started looking at isolators and finally got mine, I was disappointed in the size of it. I got a 200 amp diode isolator. I figured I could fit it under the hood but it was way bigger than I thought. I want to say I paid like $100 shipped for it, give or take a couple of bucks. When I sold it, I sold my D31A yellow top and the isolator for $135. The kid that bought it from me got an awesome deal.

 

[silenkiller 10+ year member]

So I could just use two of these, and split the alternator between them both?

I honestly can't find a diode isolator that can handle over 300 amps. At least that isn't like 500 dollars. Maybe the solenoid is better than nothing eh?

 

[ejschultz 10+ year member]

Honestly, I'm not sure if the alternator would be split between them or if it would combine the batteries to look like one battery to the alternator. The latter is more likely. With the setup that bcae1.com shows, you can shut off the charging cycle so the batteries are completely disconnected. This would be useful for running the car in ACC and not wanting to drain both batteries. When you start the car, you can flip the switch to charge the back battery and the other switch would be in the off position so the amps would not be getting any power so the battery would be able to get a full charge without discharging. With both switches in the on position, the back battery will charge and run the system. Your system at that point will be completely isolated from the front battery, which is what you would ideally want.

 

[ultimate157 5,000+ posts]

Moral of the story: Forget the isolator.

 

[AlterEgo99 5,000+ posts]

So I could just use two of these, and split the alternator between them both?
I honestly can't find a diode isolator that can handle over 300 amps. At least that isn't like 500 dollars. Maybe the solenoid is better than nothing eh?

Check out Hellroaring isolators.

 

[Sarthos 10+ year member]

Run two alternators, then you don't need an isolator.

 

[ejschultz 10+ year member]

Run two alternators, then you don't need an isolator.

This would be assuming one of the alternators is for the vehicle and the other is for the system.