JL Battery Died

[Dp227]

Never seen a battery this low. No warnings signs until it wouldn’t start. Then it just refused to try after 1 click.

Are there typically no warning notification when it’s routinely sitting below 12.4 v? I did bypass the aux battery 12 or so months ago if it matters.

Replaced the battery with an Odyssey H7. Just surprised the original still worked anywhere near that number.

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[AndySpill]

Well, one "warning notification" is the passage of time. I don't know how old the dead battery was, but I do replace mine after 3 years.

I do appreciate though that you would have liked to see some diagnostic on the vehicle suggesting that you test the battery before its death.

 

[Dp227]

Well, one "warning notification" is the passage of time. I don't know how old the dead battery was, but I do replace mine after 3 years.

I do appreciate though that you would have liked to see some diagnostic on the vehicle suggesting that you test the battery before its death.

For sure.

The battery was from 2021. I don’t fault it failing, but I do wish an advance notification had shown up. Thankfully I was home so it was a non-issue.

 

[jromanmd]

I use this: BM2 Bluetooth Battery Monitor 12V Car Battery Tester for Lead Acid, Auto Battery Load Tester with Cranking Charging Test, LowVolt Alarm for Car/RV/Motorcycle/Truck/Boat/Solar Power System

Allows my iPhone to monitor voltage, charging and overall health. I agree with the response above - if its 3 years, you are using at your own risk every day.

 

[Jeep Wick]

For sure.

The battery was from 2021. I don’t fault it failing, but I do wish an advance notification had shown up. Thankfully I was home so it was a non-issue.

My battery died 3 years to the day from when the Jeep was built. I replaced with a new AGM which I suspect will last much longer.

 

[NJJeep Guy]

My Jeep made it 5 years. Felt great compared to all the 3 year stories I see here.

 

[AndySpill]

I use this: BM2 Bluetooth Battery Monitor 12V Car Battery Tester for Lead Acid, Auto Battery Load Tester with Cranking Charging Test, LowVolt Alarm for Car/RV/Motorcycle/Truck/Boat/Solar Power System

Allows my iPhone to monitor voltage, charging and overall health. I agree with the response above - if its 3 years, you are using at your own risk every day.

Jon:

Devices that test voltage are great, don't get me wrong. And certainly if that voltage is failing, it's a sign of something wrong.

But load (not simply voltage) testing the battery, which tests its ability to deliver power, is IMHO the gold standard. Many auto parts stores will let you borrow a load tester.

https://www.harborfreight.com/100-amp-612v-battery-load-tester-61747.html

And if you have a dual AGM battery JL and are running both batteries it would be wise to temporarily disconnect the batteries by yanking the cable off the negative post of the main battery that leads to the Aux battery.

This is the cable that doesn't have as its distal end the body ground on the passenger's side under the hood: leave that cable connected.

With this temporary disconnection in place put the load tester's leads on the main battery's terminals. You'll now be testing only the main battery, not a composite of both batteries: the latter of which can at times give misleading results if one battery compensates for the other weaker one.

Move the load tester's negative side over to the cable you just disconnected. This now becomes a load test of only the Aux battery; yes, even as the load tester's positive side remains on the positive terminal of the main battery.

Reconnect that cable when finished.

 

[Dzljep]

My JLURD is a 2020, it made it to almost exactly 5 years on the original batteries. It did only have 15,000 miles on it, but sitting usually is worse for batteries, so I feel very lucky!

 

[WillysMeow]

I've had many AGM batteries over the years and my and my friend's experience with Odyssey batteries is that they last 2 years if your lucky and won't stand behind their warranty if you bought online. Will never buy another Odyssey battery again.

Factory batteries AGM or not usually on average ime last 3 years give or take. I always replace with good quality AGM.

Optima used to be good but they aren't lasting nearly as long and are now made in Mexico. I've had good luck with several Exide AGMs from local battery store. Currently have a couple Costco Exide AGMs.

 

[entropy]

Load test occasionally and ALWAYS monitor voltage and charging patterns. When a battery starts to fail you will notice it wont hold charge and the alternator would be on constantly. This happens when you see 14 volts or so when running the Jeep. If you notice this, charge the battery with a battery maintainer and then keep monitoring to see how it behaves. If it quickly goes back to charging voltages it is probably time to replace both batteries.

If you bypassed the AUX you can plug it back in and start the Jeep in case of an emergency. That assuming you maintain your disconnected Aux.

 

[WillysMeow]

@entropy more good advice and yes load test is the only test that matters, assuming battery has been charged to proper capacity before load testing. Ima delete the auxiliary battery and pull the fuse for ESS, hate that crap and it's very bad for the engine.

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