Dual battery Installation (JK's post from TF)

[vatahoelt]

i'm somewhat interested in doing this oem style. but even with a parts guy hookup, the price for everything is still pretty high. wowsers

I did have a question about the 2nd battery. How important is it to be the same as the main battery?

 

[TWITCH101]

Bought mine from a dealer yesterday....they didn't have one in stock so they ordered....had it in less than 24 hours, and only cost me 35 after tax. I think that isn't bad considering everywhere I could find one online was averaging $30 plus shipping. Install was literally a bolt in. took about 10 min....thats counting the time it took me to get my tools out until the time I was done and had my tools put away.


I plan on trying to find a regular 12v battery that is shorter and will allow me to reuse the brace, I just really like the look.

I don't think the battery type will make a big difference but I could be wrong. I just don't see any relevance in brands, I mean, 12v is 12v and Current is Current no matter whose sticker is on the box. But thats my view.

 

[bolo1g2]

From what I've read, if you don't run some kind of isolator/relay between the batteries, they need to be very similar. if you run an isolator/relay then you don't have to worry about the batteries being the same. i used a relay in my setup.

 

[TWITCH101]

after doing a quick google search I discovered that its not recommended to use differenct chemistry batteries...I'm assuming alkaline and nickel???? Also an issue might be the type, deep cell and what not...don't want to get different types because one battery will drain the other down constantly, this causing premature death of one battery.

 

[OmarR]

thanks, I think I'll order it asap....been wanting to do this for a while. Omar I have a question for you. So I'm driving down the road and come to a stop sign. right as I'm stopping I see my voltage meter drop significantly and my engine seems to want to stall. It only lasts a second or less and goes back to normal. doesn't do it every time just about 1 of of 4 times. could this be a bad ground?

Internet diagnosis can be difficult

Since it doesn't cost anything, I would definitely check your grounds and your battery connections to make sure they are tight.. Main grounds for the BCM and PCM are between the heads and the firewall, at the rear of the block. Yes, they are a pain to get to and you will need a long extension.

Is your accessory belt old? I would change that as well. It could also be somethng a little more such as the changing of fuel-to-air ratio (going from throttle to full stop) and maybe a tune-up is in order?

 

[TWITCH101]

Also, headlights dim as well, and if I'm running my ac on high I can hear the fans slow down. I'll check my grounds when it warms up a little more.

How much does a tune-up cost? I got brand new plugs and wires.

 

[WildBill]

I would disconnect the second battery and drive for a bit to see if the problem continues. It could be something like a weak Idle Air Control and not the electrical. i.e. the dimming could be because the rpm is dropping.

---------- Post added at 11:12 PM ---------- Previous post was at 11:06 PM ----------

On the battery topic, I would do matched as closely as possible. Both Lead-Acid, same brand, same CCA. CCAs may be rated differently by different manufacturers. If different batteries are used, one will discharge at a different rate that the other and one battery WILL try to charge the other. I wouldnt mix a deep cycle with a standard Lead-Acid, nor with an AGM or drycell.

 

[TWITCH101]

Yea I'm def gonna match amps and type if i can....o think it will only be a big issue it its two completely opposite batteries.
And I only have one battery right now.

 

[Z-56 Hoe]

Thanks