dual battery wiring better way?

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=98154
Printed Date: May 13, 2025 at 6:47 PM

Topic: dual battery wiring better way?

Posted By: hardwarz
Subject: dual battery wiring better way?
Date Posted: October 21, 2007 at 1:50 AM

I'm about to hook up a dual battery. I want the batteries to be isolated when the engine is off. I want to be able to flip a switch in the vehicle to jump start the vehicle. I want dual batteries when the engine is on, and I want to be able to press a button and turn off the charging of the 2nd battery.

S = Solenoid
SW1 = Jump Start switch
R = Relay
SW2 = Stop charging of 2nd battery switch

Is there an easier way to wire this and still do what I want it to do?

posted_image

Thanks

Hardwarz

Replies:

Posted By: still_walkin
Date Posted: October 21, 2007 at 5:50 AM

it s possible sounds like it might work but i wouold add a rely there to prevent the two batteries bbeign coneccted when the engine is on beacuse your alternator has to charge two batteries. but you said you wanted to flick a switch to have the second battery jump start the car. is ther second battery going to power your system. also if you get a new battery you have to buy 2 because you have a 12 volt system in your car and when you make it a 24v system if one battery is newer than the other you are going to have a volt problem. the batteries have to be like in age size and wattage. i was goign to do it but i didnt want to invest in two batteries, why is it you want two batteries what your current system . my advice is get a hp alternator and do the big 3 .

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1993 sdv
Alpine 4x6 6x9 5 1/4 swr-10d4
alpine v60
12.5 VGA flip down
Nettop pc w/10" touch screen
78nova
5-re audio 5x7 ,10" sub &
Xtx-500.5
"Take the faceplate off get the jumperpack"

Posted By: hardwarz
Date Posted: October 21, 2007 at 2:20 PM

The batteries are running in parallel. It's a 12VDC system, not a 24VDC system. If you wire them in series, then you'll have a 24VDC system.

Both batteries are charged from the alternator when the engine is on and running. When the engine is off, the 2nd battery is isolated from the primary battery and can be used for jumping the first battery.

The 2nd battery is going to run power to the stereo system, fog lights, overhead lights (when I add them) and other accessories.

Hardwarz

Posted By: still_walkin
Date Posted: October 21, 2007 at 4:11 PM

Seems like it will work upgrade the alt. Cause the stock one won't cut it. Also two new batteries are in play and the big 3

-------------
1993 sdv
Alpine 4x6 6x9 5 1/4 swr-10d4
alpine v60
12.5 VGA flip down
Nettop pc w/10" touch screen
78nova
5-re audio 5x7 ,10" sub &
Xtx-500.5
"Take the faceplate off get the jumperpack"