Best Battery Isolator

[boorob29]

What is the best battery isolator out there?

[boorob29]

If you are interested I got 2 use ones, one is a Stinger SR200 and the other one is PAC-200.

I have been told by people on other forums that you don't need them if you drive your car everyday. Is this true? I was under the impression that the batteries would discharge each other over time if they weren't isolated.

[CalusaCustomConcepts]

The point of a battery isolator is to separate the secondary battery from the primary battery when the vehicle is not running. This is usefull so that you don't run both of your batteries down so weak that you can't start your vehicle.

There are several manufacturers that make good isolators. The electrical soleniod type (that have a wire that controls the on/off function) are nice because they literally separate the connection from the front battery to the back battery. But they are prone to corrosion issues with the contacts. The industrial market (RV's, heavy equipment) has driven the manufacturers to make better quality solenoids, so this is less of an issue.

The old school diode type are more reliable. They look like a miniature amplifier because they have a heatsink. Inside of the unit is a set of diodes that electrically separate the front from the rear. They are prone to heat failure, especially if you buy one that is rated less than the current you are drawing through it.

But people are correct when they tell you that you don't need one if you run your car when you play your music. If you build up your electrical system with a larger amperage alternator and back-up batteries, then you don't need an isolator.

In fact, the use of an isolator can blow up your amps. The amps need a strong input voltage signal to produce power. If you run your system on an isolated battery for an extended period of time you run the risk of reducing the input voltage to the amp. This will make the amp work harder and produce transistor-destroying heat. Low voltage is amp suicide.

We recommend that you invest in a beefed up charging system, back-up batteries, and more/better power wire. If you do have the need for running your system for extended periods of time at high volume with the engine off, then you should think about an external 120v/12v power supply.

Now, it is true that 2 batteries of different size/age/type will create a leveling effect that benefits the weaker battery at the expense of the stronger battery. This is not so much of an issue if the batteries are charged regularly(daily driven).