Dual Battery With PAC 200 Isolator Relay

[JacobRiley]

I have a 2001 Yukon Denali and installed a 1500 amp to power two subs last March and it worked fine until this past February when the car started to die, I went in today and bought two new batteries and my friend let me have his PAC 200 Isolator so that I could use only the second battery while the car is off and my music is playing. How would I go about installing this? Could I wire a switch that allows me to just turn on the second battery even though the car is off so that I don't drain the start battery? Also, would it be safe to put the second battery under a back seat? it has no room on the top as the seat is on top of it.

 

[chevy_man]

Don't put a battery in the passenger compartment unless it's in a sealed battery box. Even a sealed battery has the chance to rupture and spill toxic shit.

You would need a switch to control the isolator. Hook your amps up to the second battery so when the vehicle is off, you can open the relay and run the stereo but still be able to start it if you kill the battery. However, I'd just wire the batteries in parallel and not worry about the isolator unless you only drive it rarely. The battery run-down protection will shut the stereo off before it gets too dead to re-start.

 

[ohiokon]

i think the pac 200 is just a 200 amp relay and not an isolator. two different things. An isolator is used to isolate multiple batteries from each other with diodes. It keeps the batteries from transfering current between the batteries which will shorten their lifespan but lets them transfer current into the system. No 2 batteries are the same and when hooked together the stronger battery will transfer current into the weaker battery and they will constantly exchange current wearing out the batteries. it might take awhile but it will kill the batteries over time. It took about a year to kill 2 group 24 batteries using a 200 amp relay in my last system. If you use the pac hook positive from your original battery to one of the big lugs on the pac, use the other big lug to send power to your spare batt. Hook up a ground to the small ground lug and hook up a switched ign to the small positive and you will be good to go. Like chevy_man said let the battery monitor from the factory do its job. If you hook it up like I did and your factory battery takes a dump on you, you can jump the relay closed and use the spare batteries to start the truck. Done it a few times with my remote start in the winter when my factory batt crapped out on me.