Two batteries in my ride

**SAScooby** · 05-10-2004, 02:00 PM

Hi All

Please can some one explain to me in plain english why I can not just install two batteries of exactly the same specifications in my car, they would be wired in parallel, this in my mind would give the same voltage give or take a half volt or so, the amp/ hour capacity would be doubled.

And surely my alternator would work less hard if the batteries were in a reasonable state of charge ? I dont want to add extra batteries if its going to drag my alternator down

If I can just upgrade my stock battery which is a 45amp hour unit, to a 80 amp hour unit, why can I not put two batteries in the car, each one at 45 amp hour and that way my pc connects to the second battery, and I should then have a tank circuit etc etc

Logic tells me this will just cost me wire and time and a second battery of the same size and type is not that expensive, where I am in the world Optima batteries are not readily available so thats out of the question.

Why I want to do this, is I am doing a serious install of the pc and sound and have run into power problems on day 2 of the install, my motto is brute force and ignorance will win through and this is the brute force part, if one battery is almost enough, two batteries should be more than enough

Will this help or am I lost ?

Thanks for any answers

**MrPerfectionest** · 05-10-2004, 02:33 PM

quick google search is all it takes

http://www.pacificpowerbatteries.com...Q/carfaq7.html

**Providence** · 05-10-2004, 10:55 PM

AFAIK, it is ok to install two batteries IN PARALLEL if you need more power. I've done it on trucks successfully in order to power two winches and various in-cab electronics (CB, radio, etc)

**Pokey** · 05-12-2004, 09:15 AM

You can add two batteries, but i would separate the two with an extremly large diode, you want them to work independly of each other.

**gotgohan** · 10-28-2009, 01:23 AM

Hello I am sorry for reviving this post yet again, I just wanted to share information to see if this is what I should do thank you.

This is a really rough picture of what I want to do with my system and trunk.

Now my question is... I researched about having two batteries in trunk... Now if I put two batteries like that with the isolator in the middle, will the audio battery get the alternator juice, or do I have to do something else?