looking at that group 31

[Tim]

i was at the local battery specialist today and asked about the optima group 31 blue top deep cell which they sell for $210.00 (sounded kinda steep). i thought i might try it and skip the extra battery and isolator equipment this time. also it seems like it would save on some of the underhood realestate while giving more reserve than a group 24(?) optima.

also asked about rebuilding my alternator for some extra power. they said it would take a day to swap guts in it but i wasnt sure how powerful i need to go with it.

what are the minimum requirements for an alternator while winching in the dark with the headlights on?

i didn't know this but on the optimas a dark case is a starting battery and a light case is a deep cycle battery. in a blue top there is a dark case starting battery available so if you are looking for a deep cell beware.

[Jerry Bransford]

I was about to buy one of the new deep cycle Group 31's until the battery guy said my present Yellow Top was still in good condition. Have you tried it for fit yet? It's pretty huge, I hope it fits without too much work.

For you Odyssey guys, I know Odyssey batteries are good but I've had such good luck with my Optima that I'm not inclined to change brands when the time comes.

[Tim]

i haven't

but i see guys stuffing two regular optimas down there once in a while so it leads me to believe it would be an easy fab job when the time comes for a new tray. perhaps a high security tray.

i saved the pictures of the side by side optimas on the tj with a/c (from a year or two ago. i was actually looking for these pics for someone not so long ago and never did find them until recently).

it looks as if there is plenty of space once the stock tray is gone. i'll get the ruler out once my tour is over this week.

[Dan-H]

Originally posted by T.Dome
what are the minimum requirements for an alternator while winching in the dark with the headlights on?

I don't think any alternator I've seen will keep up with the current draw of a winch.

Stock alternators are in the low 100 amp range. I've seen mean green alternators that put out 200 amps.

Winches can draw 200+ to 400+ amps depending on the load.

Add another 10 to 15 amps for headlights, markers, etc.

even with a high output alternator, you are still draining down the battery.

how much?

so look at you max current draw, say 400 amps, your alternator output, say 100 amps, and if you winch for 3 minutes, you have used 1200 amp-minutes from your battery and alternator. in this three minutes, your alternator supplied 300 amps and your battery was drained down 900 amps.

so you need to let the alternator charge the battery back for 9 minutes (with no load on it) to return the battery to its previous charge.

This assumes "optimal" charging, which isn't likely, so add a loss factor (any guesses??) I'll say 25+/- % to account for inefficiency in the charging system. Add this to the recharge time, so in the above example you would need to recharge for 11 to 12 mins.

I'm could be off on this because the computerized charging systems may not charge at full alternator rating so it may be longer...

a larger alternator helps by contributing more current during winching which means less battery is used, and the battery can be charged faster.

with a 200 amp alternator. 3 mins winching at 400 amps uses 1200 amp minutes. 600 amps come from the alt, 600 amps from the battery. to recharge those 600 amps, (again full charge 100% efficiency) takes 3 mins. realistically it will take longer.

so I guess the quick answser is "as big as you can get"

another power hog is your heater fan blower so if it is chilly, turn it off when winching.

[Tim]

Originally posted by Dan-H
I don't think any alternator I've seen will keep up with the current draw of a winch.

this i understand.

Stock alternators are in the low 100 amp range. I've seen mean green alternators that put out 200 amps.

my stock 97 tj alt puts out 70 amps i believe. the newer models came with a higher amp alternator. it is suprising they would put such a small one on a rig with a/c.

Winches can draw 200+ to 400+ amps depending on the load.

i have the 8274 which pulls down more than 400 amps. i cant remember the exact number but it is alot.

a larger alternator helps by contributing more current during winching which means less battery is used, and the battery can be charged faster.

so I guess the quick answser is "as big as you can get"

thanks for all that info. i know that no TJ alternator would ever keep up witha 400+amp draw or even a mean green. one of the other concerns i had and forgot to mention was the possibility of getting too many amps. could it have a adverse effect on the rest of my electrical system when i am not winching? what i am asking is how would a higher amp alternator work on a real world jeep? (not a mall crawler.. not a rock buggy)

thanks!

[Stu Olson]

Tim,

I could dig through my FSM if need be, but I am quite certain I read that the A/C equipped vehicles came with the heavy duty alternator, which is something around 117 amps or there abouts. So, yours might be as small as you think!

[Tim]

Originally posted by Stu Olson
Tim,

I could dig through my FSM if need be, but I am quite certain I read that the A/C equipped vehicles came with the heavy duty alternator, which is something around 117 amps or there abouts. So, yours might be as small as you think!

yes, they did as you said above, but my 97 came with stock a/c and puney alt. lucky me dad got the big alt in his 98 and he has aftermarket air... i think we should trade right away!!

[Dome]

NOt.

[Stu Olson]

Originally posted by T.Dome
i think we should trade right away!!

I'm thinking that while he is away at work, you could swap it out and no one but you and I would be the wiser!

[Dome]

Don't give him any ideas. I've got the serial number written down, so I would find out sooner or later. Any ideas if there will be a JU run to Moab next year?? If not maybe we could do something next May. It was a great groop to run with this year, would sure like doing that again.

[Robert J. Yates]

Originally posted by Jerry Bransford
For you Odyssey guys, I know Odyssey batteries are good but I've had such good luck with my Optima that I'm not inclined to change brands when the time comes.

I am running an Odyssey because my Optima Yellowtop crapped out after 25 months.

[Jay]

Robert, That because your letting your girl friends plug other things in you system........Big draws....

[Stu Olson]

Originally posted by Dome
Don't give him any ideas. I've got the serial number written down, so I would find out sooner or later. Any ideas if there will be a JU run to Moab next year?? If not maybe we could do something next May. It was a great groop to run with this year, would sure like doing that again.

Yeah....there will be one, even if I have to put it together. I'll have to get with Josh and get details on where he has the flags made. I already know where the pot luck dinner is going to be held.

[Tim]

Originally posted by Stu Olson
Yeah....there will be one, even if I have to put it together. I'll have to get with Josh and get details on where he has the flags made. I already know where the pot luck dinner is going to be held.

his mom had actually sewn all the flags. i dont know if she took care of having the screen printing done.

[Tim]

Rob,

thank you for e-mailing me that link. their price came in $45.00 less shipped!!! i will do this pretty soon when i can get together with my guy at work to weld up a new battery tray (not at work of course )


went out on a trail today to break in a first timer. she had a blast, its always fun to pop someones jeeping cherry!

[mnjeeper]

Originally posted by T.Dome
Rob,

thank you for e-mailing me that link. their price came in $45.00 less shipped!!!

Is that for an Odessey?? I need that link if it is. My battery sucks....

[Tim]

Originally posted by mnjeeper
Is that for an Odessey?? I need that link if it is. My battery sucks....

OPTIMA BLUE [LINK]

[Robert J. Yates]

http://www.batteryweb.com/odyssey.cfm

Odessey PC1200 (what I'm using as are others here) for $145. Screw Optima.

[mnjeeper]

Cool, the PC1200 is the one I've been thinking about. One question.....I've been leery of buying an auto battery online. What about warranty?

[Robert J. Yates]

I didn't buy mine on-line so I couldn't say but there are several here who have used that link that I posted and I have yet to see anyone with a bad experience. Great battery for the price IMO.

[mnjeeper]

I suppose it won't be so bad as long as I keep my crappy current battery in case something goes wrong and I need to ship it somewhere....

[Robert J. Yates]

Look at it this way - I bought my Optima locally and it crapped out after just 25 months. The store located all of 5 minutes from my house said tough luck but we'll make you good deal on another Yellowtop. Yea right. And I'm sure there is a nice bridge for sale in NY too

My Odyssey has been in my rig for almost 2 years with no problems, not even an inkling of one and that is after I have left my dome light on all night on numerous ocassions or have used the stereo in my Jeep while camped until I was tired of listening to it and last but not least, subjected to various winching activities on more ocassions than I wish to actually confess to

[Tim]

Originally posted by Jerry Bransford
I was about to buy one of the new deep cycle Group 31's until the battery guy said my present Yellow Top was still in good condition. Have you tried it for fit yet? It's pretty huge, I hope it fits without too much work.

For you Odyssey guys, I know Odyssey batteries are good but I've had such good luck with my Optima that I'm not inclined to change brands when the time comes.

crawled under the hood with optimas dimentions. it looks like it will fit without too much trouble. i think i will need a third hand when i do put it in.

i had an optima in my yj also. it worked great so i am also willing to stick to what has worked well for me.

robert. thanks for your link. i am in the middle of reading through the website now. i see there are three group 31s and i cant decide whats different about them yet. dimentions and weight are the samey-same. guess i'll keep on reading...

[Jeff Weston]

Originally posted by Robert J. Yates
I didn't buy mine on-line so I couldn't say but there are several here who have used that link that I posted and I have yet to see anyone with a bad experience. Great battery for the price IMO.

Batteryweb kicks ass! I called in my order and the guy was nice and friendly as could be and got it to me mach schnell. Like Robert's, mine has worked flawlessly. The terminals are better than the Optima and it has a metal case. What more could you want?

Check out this LINK in the archives.

[Stu Olson]

Originally posted by T.Dome
his mom had actually sewn all the flags. i dont know if she took care of having the screen printing done.

The sewing is not an issue. I am sure Donna would donate some time to help with that. Lord knows she can sew! I'll have to find out who did the screen printing for him.