PDA

View Full Version : Double battery


exopar
01-16-2001, 06:44 AM
Hey guys

Need some tech tips. I do pretend to add a second battery to my FSJ, do I need some special wiring or any accessory for it?
Any idea where to find it?
Any special suggest?
I guess connection needs to be done in parallel, this is in order to support a winch.

BobBarry
01-16-2001, 07:03 AM
<BLOCKQUOTE>quote:</font><HR>Originally posted by exopar:
Need some tech tips. I do pretend to add a second battery to my FSJ, do I need some special wiring or any accessory for it?
Any idea where to find it?
Any special suggest?
I guess connection needs to be done in parallel, this is in order to support a winch.<HR></BLOCKQUOTE>

The best way to hook this up is by using a "battery isolator", which enables you to run off one or the other battery, or off both.

I don't know where the best source for that item would be for you in Mexico; around here, large chain auto-parts stores, 4x4 shops, and, I believe, boating supply shops, carry them.

If you hook them up permanently in parallel, they will discharge each other; no two batteries are identical, so one will have a little less charge than the other. If hooked in parallel, the battery with more charge will try to charge the battery with less, which will then try to charge the other battery back up, and back and forth, until the batteries have discharged themselves.

------------------
Bob Barry<UL TYPE=SQUARE>* '78 Cherokee 4-door
* '88 Grand Wagoneer[/list]http://studentweb.providence.edu/~rbarry/wheels/

exopar
01-16-2001, 07:18 AM
Thanks for the info

Any WWW address where to check for it?

Regards
Ray

Snakeyes_Tx
01-16-2001, 10:36 AM
Bob, isn't that generally true only with using a new and an old battery together? I've heard that is you use two new unused batteries together that it wouldn't be an issue. Before knowing this, I used to used batteries, one 900 and one 550CCA batteries that I managed to get both to fit in the stock location... the 550 was a sidepost and I ran its other end to the two top posts.

With the discharging idea in mind.. then why doesn't that apply with 24V serial systems? I know one positive goes to the other negative, but I'm not too keen on its discharging property.



------------------
Snakeyes_Tx
86 J-20 "The Rusty Dinosaur"
360/727/208/44/60 &lt;- 2nd of all of them.
"If you don't know what the numbers mean, you don't need to be here!"

WINGO
01-16-2001, 01:33 PM
exopar:

Check out this thread about dual batteries:
http://www.ifsja.org/ubb/Forum2/HTML/001516.html

J. C. Whitney has kits for this in their catalog in the RV section. You can also check out their web site at:
www.jcwhitney.com (http://www.jcwhitney.com)

Good Luck!

------------------
WINGO
Vineland, NJ
USA
1984 GW 360
Rough Country/Heckethorn 2 1/4" AAL (actual lift)
Rough Country/Heckethorn Nitro 9000 Shocks
Performance Accesories 3 " Body Lift

Soon to Have:
1- Rhino Grill
2- Alis-Chalmers Orange & Black Durabark exterior paint.
3- 33" X 12.50" tires

[This message has been edited by WINGO (edited January 16, 2001).]

BobBarry
01-16-2001, 02:56 PM
<BLOCKQUOTE>quote:</font><HR>Originally posted by Snakeyes_Tx:
Bob, isn't that generally true only with using a new and an old battery together? I've heard that is you use two new unused batteries together that it wouldn't be an issue. Before knowing this, I used to used batteries, one 900 and one 550CCA batteries that I managed to get both to fit in the stock location... the 550 was a sidepost and I ran its other end to the two top posts.

With the discharging idea in mind.. then why doesn't that apply with 24V serial systems? I know one positive goes to the other negative, but I'm not too keen on its discharging property.<HR></BLOCKQUOTE>

I do have to admit that this is purely hearsay on my part; but I've heard it from a number of reliable sources over a long period of time, so I felt confident offering it up.

Even with two brand-spanking new batteries, however, they become used ones real quick. I suppose the more identical they are, the longer it would take for them to mutually discharge themselves, but eventually the variations between the batteries would get worse.

------------------
Bob Barry<UL TYPE=SQUARE>* '78 Cherokee 4-door
* '88 Grand Wagoneer[/list]http://studentweb.providence.edu/~rbarry/wheels/

scotty
01-16-2001, 04:03 PM
you can get a heavy duty dual battery switch at any good boat store,they range in price from $20 to $40. you just turn a big a*s dial to select bat A,bat B,A+B,or OFF,which is very handy in doing electrical work,just turn the switch,no reason to get out a wrench and disconnect cables.

most isolators will keep one bat from discharging the other,and send the charge to whichever bat needs it,but with that setup you cant really chose which bat you want to use,can you? also most ive seen are at least the price of a good marine dual bat switch.

ive got mine hooked up right now with an extra starter solenoid,but i feel the switch is a much better way to do it,and have one to install(sometime after the engine,tranny,xfer,axle swap,rear disc,vw turning brake,and winch install) ill get to it one day... http://www.ifsja.org/ubb/smile.gif

------------------
scott
85 grand wagoneer
258 with motorcraft 2bbl/904/twin stick dana 300/dana 44/welded amc 20
38x15.5 gumbo mudders
snorkel/dual batteries/onboard air/"custom" convertable
3 inch body lift/mostly stock suspension/"modified" fender openings
custom front/rear bumpers and brushgaurd

T18/dana-spicer 18 with drum E brake and PTO,and offset dana 44 swap very soon
BIG tow truck PTO winch and full roll cage install shortly thereafter
searching for jeep 4.0 six engine

now we can do some 'wheelin!

River Beast
01-16-2001, 10:08 PM
FYI... Fulmetal has a nice swtup that he runs... one battery for normal "actual" use and the other for his accessories.... Hope he posts here and tells you how he' got his.... he has told me before but dangit if I can't remember the "exact" way he did hid... http://albums.photopoint.com/j/AlbumIndex?u=187566&a=7042531

rows 8, 9 and 10 of the link above show his setup... check it out...

------------------
Todd
78 Wagoneer, "River Beast"
360/TH400/QT
Dana 44's locked w/ 4.89's
39.50x15x15 Super Swamper TSL's
7" SOA in front-7" Rear Shackle Inversion Mods
4" Skyjacker Softride
3" Trailmaster Bodylift
My FSJ site: http://www.geocities.com/spazz4life (http://www.geocities.com/spazz4life)
My E-mail: monster_fsj@hotmail.com
"If you can't stop...SMILE as you go under!"

'93 3/4 ton 4x4 Suburban...a.k.a. "FSJ Hauler"

Steven Miller
01-17-2001, 10:40 AM
I have been using 2 batteries in parallel (without a isolator) for years. The "right way" to do it is with a Isolator. I recently shipped both my Rigs from Germany to Seattle - on the boat for over 2 months - and they fired right up.

fdwyer
01-17-2001, 11:22 AM
This is the isolator/combiner I'm going to be using. I already have the thing, but haven't hooked it up.

Its an Isolator Combiner in one and you can check it out here:
http://www.hellroaring.com

Regards,

Frank