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Discussion Starter #1
First post & proud new FJ Cruiser owner! I know this topic has been discussed, but I’ve been searching the forums endlessly on deep-cycle batteries and they all seem outdated...

I’m taking a 10 day trip through “The Maze” in Moab this coming May. I’m looking for a reliable deep-cycle battery that will be able to run the following...

1) ARB Fridge
2) Camping lights (small LEDs on the side of the roof rack)
3) Winch
4) Overnight charging for cameras, phones, GoPros & other accessories

After spending over 3 hours researching (and yes I’ve used the search bar) it seems the Sears brand was once the most recommended, but they’re now discontinued. Optima also has extremely mixed reviews... once they were amazing & now they’re trash. Odyssey is the gold standard, but some are claiming there are manufactures who make the exact battery and the only difference is the branding & warranty. Adding to the complexity, some people put in marine batteries, fabricate new trays, & do other modifications to fit other batteries. I’M COMPLETELY LOST!

If anyone out there can help me out, it’d be much appreciated. Price range is ~ $300. It’d be nice if I could get a battery that fits in directly, however if there’s a one with better specs & is more applicable for this trip, then I’m willing to do some modifications. THANK YOU!
 

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Odyssey is the gold standard and anyone who claims to have a comparable battery is full of it. The sears die hard platinum was formerly made by Enersys, the parent company of Odyssey and that’s why they were so good. Enersys is a Pennsylvania based American company and quality is goal one and their customer service is excellent.
Optima outsourced to Mexico years ago and started going cheap using recycled lead in their patented spiral cores, their warranties dropped off dramatically as quality diminished.
I will say if you’re looking for mobile power sources for charging gear and such Goal Zero has excellent gear but pricey.
In the end for running fridges, winches, and a solid reserve the Odyssey is the path but just know you MUST modify your charging system to properly charge the Odyssey or for that matter any AGM sealed battery or their life will be greatly reduced. It’s an easy mod so it’s no sweat.

Good luck!


 

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Odyssey 31M-PC2150ST.

It drops into the existing space (you'll need a new plastic battery tray) and it's just about as big as you can fit. 100 amp-hour nominal capacity (over 20 hours), 205 minute "reserve capacity" (205 minutes at 25 amps). You want the "st" model; that will put the positive & negative terminals in the right place for the FJ - negative on the "outside" near the body.

I did that and the charging system update here: 101Firedog's fire dog: ARCA9 - The Electric Upgrade
Might as well upgrade your core power cables while you're at it, since the FJ's terminal connectors (probably) won't reach the terminals on the new, larger battery - mine were pretty tight with no slack from the factory.

If you're going to be camping and running lots of electrics, and then running down a battery and charging it, you might want to upgrade your alternator as well - it's not cheap! But, Toyota made an alternator for the 4Runner that is the same external form factor as the FJ's, but that puts out 130 amps instead of the 100 that the FJ's alternator produces. That's a 30% increase in available output and will give your electrical system an easier time recharging your battery after an overnight drain (or running the fridge in the back of a hot car in Moab....).

I did that here: 101Firedog's fire dog: ARCA9 - 130A Alternator Upgrade

Something I haven't done that you might consider, specifically for Moab: A heat shield on your battery (as the 31M-PC2150 has plastic walls; there's no metal-wall option). There's a decent discussion about that over here: Battery heat shield wrap advice needed
 

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Odyssey 31M-PC2150ST.

It drops into the existing space (you'll need a new plastic battery tray) and it's just about as big as you can fit. 100 amp-hour nominal capacity (over 20 hours), 205 minute "reserve capacity" (205 minutes at 25 amps). You want the "st" model; that will put the positive & negative terminals in the right place for the FJ - negative on the "outside" near the body.

I did that and the charging system update here: 101Firedog's fire dog: ARCA9 - The Electric Upgrade
Might as well upgrade your core power cables while you're at it, since the FJ's terminal connectors (probably) won't reach the terminals on the new, larger battery - mine were pretty tight with no slack from the factory.

If you're going to be camping and running lots of electrics, and then running down a battery and charging it, you might want to upgrade your alternator as well - it's not cheap! But, Toyota made an alternator for the 4Runner that is the same external form factor as the FJ's, but that puts out 130 amps instead of the 100 that the FJ's alternator produces. That's a 30% increase in available output and will give your electrical system an easier time recharging your battery after an overnight drain (or running the fridge in the back of a hot car in Moab....).

I did that here: 101Firedog's fire dog: ARCA9 - 130A Alternator Upgrade

Something I haven't done that you might consider, specifically for Moab: A heat shield on your battery (as the 31M-PC2150 has plastic walls; there's no metal-wall option). There's a decent discussion about that over here: Battery heat shield wrap advice needed
I use the heat shielding and it really makes a difference keeping the battery cool especially with the proximity to the radiator and engine with 2150. Great mod especially for Moab or Death Valley.
 

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Northstar!
Another great American made battery that’s catching on pretty fast. I read an article where they actually said the Northstar is better than the Odyssey group 31 by a fraction because of AH and RC, it’s splitting hairs but Northstar is definitely quality with a comparable warranty.

The only thing the article didn’t mention is that the Odyssey has a 5-6 second burst CA of 2150 before dropping to 1350 for whatever it’s worth.
 

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Well now I see the Northstar has a pulse of 2150 as well, interesting, very closely matched.
 

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Discussion Starter #9 (Edited)
THANK YOU EVERYONE FOR YOUR FEEDBACK!

After more research & looking into everyone's suggestions, I decided to get a NorthStar NSB-AGM31. This was a brand I was unfamiliar with until I posted this discussion board. NorthStar has outstanding reviews & is highly praised among owners. It also comes with a 4 year warranty, which was a big selling point for me. I was looking into the Odessey 31M-PC1250, which also has an amazing warranty, however it was ~ $100 extra in price. Between being at college & owning an FJ, I'm already poor enough as it is. I purchased it for $350 on Amazon (with free shipping) so I feel like I got a reasonable deal. On camelcamelcamel.com (highly reccomend this website for Amazon orders - shows price fluctuations over time & you can track items when their price drops to a certain point), this battery was at a low selling point, so that's good!

Some things I still need to do/consider -
1) Find a new tray that will fit the battery (that's if it doesn't fit in the stock location). If it does fit in the stock location, is there any problem with using it? Since it sits higher, I assume the posts won't be long enough to reach the mounting points. Thinking about using a strap and calling it good? If anyone has recommendations for group 31 battery trays & mounting solutions, I'd really appreciate it!
2) Modify the terminals so they reach the battery terminals. This shouldn't be too hard... planning on getting the same gauge wire & extending it out a couple inches.
3) The alternator - this is another thing I didn't consider until 101Firedog discussed it. I would like the FJ to run at 13.7-14.7 volts while running. I'm still a noob at this kind of stuff (especially electronics) so I hope my line of reasoning here is correct... if the battery voltage is below the standard (say 12 volts) would this impact engine performance (since the spark plugs aren't being fed enough voltage?)

Thanks again, everyone. These posts really helped narrow down my search! CHEERS!
 

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1) Find a new tray that will fit the battery (that's if it doesn't fit in the stock location). If it does fit in the stock location, is there any problem with using it? ... thinking about using a strap and calling it good?
It almost certainly won't fit because the battery will almost certainly have a larger footprint than the stock battery; it won't be able to sit in the tray. Trays are cheap, though. Especially with the hefty bigger batteries, you just want something to distribute their weight, help hold them in place, and make sure that the battery isn't pressing all its weight directly down on the sharp, strong, and heat-conductive metal of the vehicle body.

Straps can work, but I found that the stock tie-down crossmember still worked fine - just needed to spend a couple dollars on some longer J-hooks from the local auto parts store. Would recommend that over a strap; it's harder to cut, corrode, and stretch metal than whatever strap material.

2) Modify the terminals so they reach the battery terminals. This shouldn't be too hard... planning on getting the same gauge wire & extending it out a couple inches.
That wouldn't be my first reccommendation... the extra length you need will be coming right off the battery terminals; these are the highest-current cables in the entire vehicle. Your cable joins must be VERY good or you risk losing current capacity (increased resistance due to incomplete contact)... which will in turn make the join heat up more than the other cables. Potentially melting or burning when you're still otherwise well within operating spec. I mean, it will probably be fine, but within a certain threshold and given a choice, one does not extend or patch power cables; one just replaces.

Also, full, un-broken cables will be tough & flexible. A join will almost certainly sacrifice flexibility, and may also sacrifice strength. Again, it will probably be fine, but just keep that in mind. Maybe extend the back end of your wiring harness - all of the small wires that each only carry a little bit of current - instead of the big thick cables that come right off the battery terminals.

I would like the FJ to run at 13.7-14.7 volts while running. I'm still a noob at this kind of stuff (especially electronics) so I hope my line of reasoning here is correct... if the battery voltage is below the standard (say 12 volts) would this impact engine performance (since the spark plugs aren't being fed enough voltage?)
While the engine is running, the computer-controlled alternator regulates the voltage to an acceptable level to run all of the vehicle's electronics. Your battery (and its voltage) doesn't really matter then.

But you're going to go and change one of those electronic components - the battery - to one whose spec is outside the Toyota factory spec. So, you will need your alternator to adjust and run at a slightly-higher voltage (14.1 minimum, probably - at least it is for the Odyssey AGM; still tolerable and within spec of all the rest of the vehicle's electronics). If you don't do this, the battery will never fully recharge, and that will shorten its lifespan (and not run your auxiliary electronics for as long - like only filling your gas tank up 3/4 of the way each time instead of all the way).
 

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Great choice!
I use these extensions on my cables, they are very heavily built and can be purchased at your local O’Reillys. They also have built in splitters so you have a couple of easy to access circuits as well. I just didn’t feel like tearing into my fuse boxes to change the cable for an extra 2” so this was a good option for me.
 
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