Installing second battery
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=53040
Printed Date: July 18, 2025 at 7:19 AM
Topic: Installing second battery
Posted By: Kalus
Subject: Installing second battery
Date Posted: April 02, 2005 at 6:54 AM
I have a deep cycle battery I want to install in the boot so my stereo / computer can run direct from it without draining the main battery. How do I wire it up to only charge when the car is running? It is only a 35Ah cell, and I will only be pulling about 15A with everything running. I was thinking of using a couple of 60A relays connected to the ignition and alternator warning light on the dash. So, when the ignition is on, but before I start the car, the alternator warning light is illuminated and there is no connection between batteries. It is not until the car starts and the alternator light goes out that it connects the main battery in series with the deep cycle for charging. Would the factory regulator handle this?
Replies:
Posted By: Kalus
Date Posted: April 03, 2005 at 4:22 AM
Noone has any suggestions at all????
Posted By: Kalus
Date Posted: April 03, 2005 at 4:24 AM
And by the way, I meant 'in parallel' not 'in series' in the original post :)
Posted By: wheelerdr
Date Posted: April 03, 2005 at 5:10 AM
The best thing to do when installing a second battery is to buy 2 of the same kind and replace you current car bat. as well. you can get kits on line all over the place with mounting brackets for the extra battery. all instructions included kits run around 100.00
-------------
Posted By: Kalus
Date Posted: April 03, 2005 at 5:32 AM
Well, the trouble is, I bought a new one for the car, then decided on the second battery idea, and bought the deep cycle. So unless I want to throw away AU$250 worth of batteries and start over, it is not on the cards :)
Posted By: wheelerdr
Date Posted: April 03, 2005 at 9:42 AM
not saying you have to do it but it is usally the best thing to do , get you kit and install it to the directions and you should be fine very easy to do
-------------
Posted By: Kalus
Date Posted: April 03, 2005 at 9:48 AM
what would these kits be called..... can you give me an idea of where to look????
Posted By: Velocity Motors
Date Posted: April 03, 2005 at 11:29 AM
What you need is a battery isolator. It will monitor both batteries and give charge to the battery that needs it and balances the charge out between the two. The battery isolators wil run between $ 50 - $ 200 depending on where you purcahse and how high end you want it.
-------------
Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: Kalus
Date Posted: April 03, 2005 at 7:08 PM
Ahhh, thank you very much :)
|