Dual Battery Question

You need to read these. there is a lot of info in the first one but it WARNS you about why they should be the same.

I did a lot of reading into all this. it was like a college level crash course when i read the book on batteries and learned about Peukert.

Series vs Parallel (Great Info)

Peukert Formula

Isolator Setup Pic

Batteries wired in Parallel
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hm good read thanks! some of those links didnt work, but the ones I did confirmed a lot of things I was wondering. I checked with several different people, who sell several different products, and then with there service techs, and we've concluded, that for my needs, and everything I layed out for them and explained why, that my best bet would be to get an identical battery and wire them in parallel without the isolator. No one is sure if I will need a bigger alternator or not. They said don't buy one just yet, worse case senario, i kill mine, and i buy one then. They told me to hook everything up, run it for a bit, and see if my batteries start to drain and not keep up. They suggested use of a volt meter, but I was wondering on the way home, wouldnt my scan guage also determine the voltage of my batteries? Anyway, thanks for all the help! Oh, and the one guy said (he may have been mistaken, or flat out lying to sell the one brand over the other) the PIAA 540s would take less than the hellas and put out more light. I have no idea, nor do I have any means of 'testing', but does anyone know anything about this? The guy sold both hellas and PIAAs. The PIAAs are about an inch smaller, so I guess I could understand that they may take less power, but, I dont know if they'd really give more light, especially since they are smaller. What do you guys think?

 

You need to get the Lumen output and compare that to the amps each draw. Get the one that has more Lumens and least amps.

 

If i looked correctly, they take the same amount of energy, but the PIAA actually does put out twice the output. That being said though, I think its far easier to convert Hellas to HID than PIAA is, so then Hellas would win...I think anyway...lol

 

hmmm those links worked for me. oh well glad you got some info out of it. identical batteries and identical age isimportant.

 

Thanks for all your help! The battery I have on hold at sears is 1 month newer than my current battery I just put in not even 2 weeks ago. Do you think it will be ok, or would that destroy everything?

 

That won't hurt it. A year differance, I might worry. 3 years or more and replace both. It really depends on age and useage.

 

great news, thanks a bunch!

Here is kind of a random question about battery terminals that I dont know if you will know or not...on these marine batteries, there are 4 terminals. 2 are the regular size terminals all batteries have. the other two are a little smaller...I wasn't sure if maybe boats have smaller terminal connectors or not...anyway, what I would like to do, is wire the batteries together using the 4 small terminals (they aren't that small, just smaller). I thought that keeping the extra big terminals would help for jumping other people etc, plus it would look nicer having the 4 little ones all attached. Do you think the smaller terminals put out less power, or will they be ok connected by them. I'll post a link to the webpage of the battery i'm talking about for a bettery visual picture.

http://www.sears.com/shc/s/p_10153_12605_02850134000P?mv=rr

 

The terminals with wing nuts are for accessories. The clamp-on posts are for starters and/or accessories

 

sooooo...does that mean I can attach the battiers together with those wing nut posts?

 

Yea. That'll work.

 

excelent, thanks for all your info and help! rep to you!

 

Thinking about ordering one i got a extra battery laying around!!
found the write up on it hear ---->http://www.yotatech.com/f2/dual-batteries-installed-198973/

List Price: $66.15
Our Price: $38.73


http://www.ase-supply.com/ProductDetails.asp?ProductCode=SP-9523A

i know the write up on how to do it has already been posted in prior post but just a reminder and a little info on the isolator being on sale