# 2nd battery electrical question
**URL:** https://forums.speedlife.net/t/2nd-battery-electrical-question/183390
**Category:** PittSpeed Automotive
**Created:** [July 7, 2006, 9:11am UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390 "2006-07-07T09:11:23Z")
**Posts on this page:** 13
**Page:** 1
### Author:  [@S10Blazed\_Si](https://forums.speedlife.net/u/S10Blazed_Si)
#### Post date: [July 7, 2006, 9:11am UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/1 "2006-07-07T09:11:23Z")
I’m wiring up a 2nd battery in my truck just to power the 12v toys but wanted to double check my thinking on the matter. My primary battery is in the stock location wired up how GM did it in 96 but with all 4 gauge wire. I plan to connect the 2nd battery in the bed with 4 gauge. I don’t think it matters - but should I make the front connection on the +positive side of the battery or on the alternator? Directly from this connection I will have a 100a circuit breaker that will go into a 100 amp relay in my cab. I will actuate this relay with the ignition. After the relay I will have another run that goes directly to the 2nd battery +positive terminal to charge it while the truck is running but will also have another 100 amp circuit breaker to go my 12v toys with another 100 amp relay to turn them on automagically when I start the truck (and manually switched for when I’m parked). The wiring for the 2 compressors I am confident is accurate and adaquate. They draw 20a max I believe each. Also, would it be wise to add a 3rd 100A circuit breaker close to the positive terminal on the rear battery? Just in case of a short? I’m looking for opinions to make this better, safer, or if I just have something totally wrong. Engineers are encouraged to help! TIA
---
### Author:  [@Pewter](https://forums.speedlife.net/u/Pewter)
#### Post date: [July 7, 2006, 9:40am UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/2 "2006-07-07T09:40:38Z")
get a daul battary kit off a deseil gm or a truck that has daul battary set up,i would have to check to see if i have one!
---
### Author:  [@S10Blazed\_Si](https://forums.speedlife.net/u/S10Blazed_Si)
#### Post date: [July 7, 2006, 10:25am UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/3 "2006-07-07T10:25:52Z")
> [@pewterss](#):
>
> get a daul battary kit off a deseil gm or a truck that has daul battary set up,i would have to check to see if i have one!
What does this kit consist of? Does it leave both batteries connected to the charging source at all times? How much is it roughly?
---
### Author:  [@Pewter](https://forums.speedlife.net/u/Pewter)
#### Post date: [July 7, 2006, 11:40am UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/4 "2006-07-07T11:40:57Z")
yes,i :dunno:
---
### Author:  [@S10Blazed\_Si](https://forums.speedlife.net/u/S10Blazed_Si)
#### Post date: [July 7, 2006, 11:47am UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/5 "2006-07-07T11:47:10Z")
> [@pewterss](#):
>
> yes,i :dunno:
I specifically want to disconnect the rear battery from the main electrical system so that I am never stuck with a dead battery from my 12v toys. Thanks though.
---
### Author:  [@Pewter](https://forums.speedlife.net/u/Pewter)
#### Post date: [July 7, 2006, 12:19pm UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/6 "2006-07-07T12:19:16Z")
u can
---
### Author:  [@S10Blazed\_Si](https://forums.speedlife.net/u/S10Blazed_Si)
#### Post date: [July 7, 2006, 12:42pm UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/7 "2006-07-07T12:42:14Z")
> [@pewterss](#):
>
> u can
Ok… I must of missed that part in one of those 4 words you used. My bad. Can you eleaborate on how it works?
---
### Author:  [@F-B-A](https://forums.speedlife.net/u/F-B-A)
#### Post date: [July 7, 2006, 12:48pm UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/8 "2006-07-07T12:48:07Z")
i have the battery isolator here for that truck. its used, but still works great, its basically a glorified relay, but easy to install
---
### Author:  [@SoLow](https://forums.speedlife.net/u/SoLow)
#### Post date: [July 7, 2006, 12:49pm UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/9 "2006-07-07T12:49:38Z")
> [@S10Blazed Si](#):
>
> Ok… I must of missed that part in one of those 4 words you used. My bad. Can you eleaborate on how it works?
now ur asking for alot…LOL…
but i’m going up to JJ’s today John if u 2 work this out and he has it, let me know if he has it i’ll grab it for u while i’m there
---
### Author:  [@S10Blazed\_Si](https://forums.speedlife.net/u/S10Blazed_Si)
#### Post date: [July 7, 2006, 1:50pm UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/10 "2006-07-07T13:50:14Z")
> [@first-bass](#):
>
> i have the battery isolator here for that truck. its used, but still works great, its basically a glorified relay, but easy to install
Sorry but I’ve already decided against an isolator. From my readings it will create a .7 volt drain on the entire system. With a relay I just need to be sure I have 2 nearly identical batteries.
---
### Author:  [@F-B-A](https://forums.speedlife.net/u/F-B-A)
#### Post date: [July 7, 2006, 1:52pm UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/11 "2006-07-07T13:52:17Z")
true you will want possible the same 2 batteries, sorry i couldnt help.
---
### Author:  [@S10Blazed\_Si](https://forums.speedlife.net/u/S10Blazed_Si)
#### Post date: [July 7, 2006, 1:54pm UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/12 "2006-07-07T13:54:37Z")
> [@first-bass](#):
>
> true you will want possible the same 2 batteries, sorry i couldnt help.
2 red tops are already checked off my list 🙂
I still am forming a comprehensive parts list that I want to run by you pending the outcome of this thread. (also posted this on a few other sites) Do you stock these circuit breakers and spools of wire? Or is it something you’ll have to order if I were to buy from you?
---
### Author:  [@F-B-A](https://forums.speedlife.net/u/F-B-A)
#### Post date: [July 7, 2006, 2:18pm UTC](https://forums.speedlife.net/t/2nd-battery-electrical-question/183390/13 "2006-07-07T14:18:58Z")
the majority of what your looking for i have in stock, wire, connectors, and such, the circut breaker i may not, i usually keep 1 or 2 around but i sold out about a week ago. i get them in next day, i just need to know what size you need thats all, i usually stock the 100amp or 150amp.
I also carry the PAC 200 or PAC 80 relay/solonoid if you havent located those yet.