Dead Optima Battery

You'll want something at least 100w or so or the largest foldable you are willing to carry around.

The panel you had should have gotten at least and amp or two in full sun. I'm guessing it was a 30 or 40w panel? Definitely sounds like it was defective at 0.2A

Id buy a general purpose "12v panel" and a dc dc charger for the battery. The panel will put out around 18v and be useful for other projects too.

This was many years ago and its use was for while the Jeep sat in the driveway. The alarm drew enough current to run the battery down over a 2-3 week period. Since then I bought a motorcycle trickle charger / maintainer with a long cord and hard-wired a 2-conductor flat plug from the battery to the grille so it can be easily connected / disconnected (and will auto-disconnect if the Jeep is backed out without disconnecting first. That came in handy a few times).

Ya know, now that I think about it, the above low battery while sitting for 2-3 weeks happened when the Optima battery was in the Jeep and I haven't had any issues with the replacement Interstate battery. I haven't connected the trickle charger since some time last year and the battery has never given me any problems.
 
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Well that was a fun read. I was out of town for a week (burning up the clutch in the rental car :ROFLMAO:).
I got the replacement battery ordered. Its almost the same size. It fits into the tray, but I'll need to come up with a new way to strap it down.
The battery does touch the AC lines. Assuming I can get it strapped securly in place, I don't think it will be a problem.
Pic1 - The replacement is +.9" wide. The other 2 are nearly identical.
Pic2 - Tight fit past the AC lines (even with the fuse panel completely out of the way).
Pic3 - Fully seated in the tray, it just touches the AC line.
Pic4 - Fully installed
Pic5 - This is the custom Nemesis lid for the Optima. I don't think I can get it to fit, even if I hacked it up

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A previous must have modified or replaced the battery mount for that Odyssey 34/78 not to fit. 34/78 batteries normally fit into a TJ perfectly, that's all I run.
 
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PO used just about every accessory Nemesis makes. This Jeep was supposted to be a display at Easter Jeep Safari in 2020.
The tray and lid fit the Optima perfectly.
I asked them if they have a different lid, but they don't. They admit that the Optima Batteries are junk now. But TJ is probably too old to design a new battery tray.
 
Well that was a fun read. I was out of town for a week (burning up the clutch in the rental car :ROFLMAO:).
I got the replacement battery ordered. Its almost the same size. It fits into the tray, but I'll need to come up with a new way to strap it down.
The battery does touch the AC lines. Assuming I can get it strapped securly in place, I don't think it will be a problem.
Pic1 - The replacement is +.9" wide. The other 2 are nearly identical.
Pic2 - Tight fit past the AC lines (even with the fuse panel completely out of the way).
Pic3 - Fully seated in the tray, it just touches the AC line.
Pic4 - Fully installed
Pic5 - This is the custom Nemesis lid for the Optima. I don't think I can get it to fit, even if I hacked it up

happened to notice a potential fire hazard.
them yellow wires have the potential to chafe the insulation off and arc directly to ground on the side of the fender.
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not sure if it was a factory thing across all the model years but mine and others like the photo below have a piece of rubber trim along that edge just slipped on. red jeep isnt mine.. im just too lazy to go get a photo of mine.
Screenshot_20210412-193239_Google.jpeg
 
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Thanks, those are the KC Lights. I didn't get everything exactly right when I reconnected. Originally I had the negative wires running across the top of the battery, probably a bad idea.
I might get one of those battery terminals with the extra connection points for accessories.
 
You guys keep showing off that trim... anyone have a source or part number? I need one before my next electrical fire.

From the posters picture...I'd try tucking those wires into the fender better and get more space for the battery.

Should be able to rig up a tie down...I have 3/4 angle iron holding my battery down. My dump trailer batteries are ratchet strapped to the bottom of the box...just cut off the excess strap and heated it up to melt it.

-Mac
 
You guys keep showing off that trim... anyone have a source or part number? I need one before my next electrical fire.

From the posters picture...I'd try tucking those wires into the fender better and get more space for the battery.

Should be able to rig up a tie down...I have 3/4 angle iron holding my battery down. My dump trailer batteries are ratchet strapped to the bottom of the box...just cut off the excess strap and heated it up to melt it.

-Mac

In no way am I suggesting there WILL be a electrical fire without the presence of that rubber strip... just pointing out simply the fact that wires making contact with a sharp edge and vibration could lead to a very possible oh shit situation.
obviously wire managing would be the correct method of attack to prevent said emergency.
 
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Optimas used to be the go-to choice, now I wouldn't trust them. A few years back (probably more than a few now) they switched production to Mexico, which by itself shouldn't have caused any issues, but that is right around the time when the quality took a nosedive. I went through 3 of them in a year on my XJ before I said no more. All of them were replaced under warranty with a dead cell, and died suddenly. All were Yellow tops. A year later, I had to drive an hour to get a buddy who was stranded in his XJ by a 3 week old Red top.

The run of the mill Interstate in my TJ has a 2017 date code on it, and still load tests good.
 
Another alternative worth looking into is the Deka Intimidator series. I used to always go NorthStar, but since their merger with Odyssey, a lot of the original NorthStar batteries are no longer available.

Note that Odyssey, Northstar, and probably Deka high end AGMs need higher alternator setpoints for longer lifespan. Odyssey in particular notes that their batteries get maximum life when charged at 14.7V. Northstar also recommended being closer to 14.8. TJs without battery temperature sensors only charge at around 13.6V, which will vastly decrease the lifespan of any high-end AGM.
 
Another alternative worth looking into is the Deka Intimidator series. I used to always go NorthStar, but since their merger with Odyssey, a lot of the original NorthStar batteries are no longer available.

Note that Odyssey, Northstar, and probably Deka high end AGMs need higher alternator setpoints for longer lifespan. Odyssey in particular notes that their batteries get maximum life when charged at 14.7V. Northstar also recommended being closer to 14.8. TJs without battery temperature sensors only charge at around 13.6V, which will vastly decrease the lifespan of any high-end AGM.

I didn't know that about AGMs - thanx for the edumacation. NorthStar always reminds me of a computer!
 
Note that Odyssey, Northstar, and probably Deka high end AGMs need higher alternator setpoints for longer lifespan. Odyssey in particular notes that their batteries get maximum life when charged at 14.7V. Northstar also recommended being closer to 14.8.

Can our ECU's internal regulator be programmed for this? Or do you need some piggyback circuitry? Or alternator tweaking?

-Mac
 
Can our ECU's internal regulator be programmed for this? Or do you need some piggyback circuitry? Or alternator tweaking?

-Mac

If you have a tuner, yes you can change the alternator setpoints. You can also use an external regulator to do the same thing. You'll just need to put a resistor in the PCM circuit to fool the PCM into thinking it has an alternator if you use a separate circuit.

If you have a battery temperature sensor, odds are your charging voltage is already close enough to make any changes not worth the effort. In the absence of the temperature sensor, the PCM defaults to the lowest voltage possible, which generally is too low.

I would recommend reading the voltage across the battery terminals after a cold start and maybe a 3-5 minute idle (measure with engine running). If it is 14.0+ I wouldn't bother unless you already have a tuner and credits on hand. (If it is 14.0+ when cold you probably have the battery temperature sensor.)
 
I got well over 10 years out of my Odyssey with the stock charging system .

Do you have the battery temperature sensor in your TJ? If it is present, the PCM will target charging at a noticeably higher voltage, which may explain why your battery lasted so long.

A lower voltage won't outright kill the battery, just shorten its useful life.