The other day my battery died and I’m trying to figure out why

[Zipper]

I had no lighting left on no mods that pull power directly from battery. The only thing I can think of is I had an AV to HDMI converter plugged into the USB port in the back seat but there was no hdmi device plugged in. Do the USB ports stay on when the car is off? Does the converter pull power when nothing is plugged into it? What do you guys think?

Sponsored

 

[Mr._Bill]

I had no lighting left on no mods that pull power directly from battery. The only thing I can think of is I had an AV to HDMI converter plugged into the USB port in the back seat but there was no hdmi device plugged in. Do the USB ports stay on when the car is off? Does the converter pull power when nothing is plugged into it? What do you guys think?

It could have been the device in the USB port. My first thought is the ESS battery is failing and draining the main battery.

 

[Mjolnir]

The aux batteries are garbage and will sporadically die. Look at all the other posts on t his.

If the aux battery is below a certain voltage the truck will not start, even though it id not the cranking battery. I bet your cranking batt was fine and your aux was drained.

 

[mazeppa]

If the aux battery goes bad it can discharge the main battery and vice versa because they are always connected in parallel except during a Start-Stop event when they are isolated from each other.

 

[ShotCaller]

Take it to the dealer and let them change both batteries. I wouldn't mention anything about leaving the converter plugged in.

Its not that easy to get to the aux battery..

 

[ShadowsPapa]

This is incorrect... This was / is an issue, in regard to the majority of 2018 JL/JLU's (not 2019, 2020, 2021 vehicles) that have not had TSB 18-092-19 completed (Power Control Update).

Add 2018 Grand Cherokee to the mix. But the dealership said "we've had a rash of bad batteries, both of yours tested bad so we replaced them under warranty".
ESS stopped working then days later it got to the point it would not crank. Jumping it or charging the battery a while got it started and it was fine for a couple of days. Then after sitting a few days, it wouldn't crank again, until I charged battery or jumped it.

There was no mention of a TSB - just "we've seen a lot of bad batteries" and our batteries tested bad. I though that was weird.

Also - according to the owners' manual, those USB ports are not constantly live - they are live for something like 30 minutes after shut down. I know I had to keep going out and starting my truck every so often so I could use the USB ports to charge my phone and hearing aids when we lost power for a week after that huge storm we had last fall.
I'd go out and the USB ports were dead, I'd start the truck, shut it off and they were live again - until next time I went out. I'd start the truck, shut it off and the ports were live again.

 

[M0untainM4n]

Funny thing... this happened the other day to my son's Highlander. I told him he had to have had something on because unless the battery is bad, it should have charged. I jumped his car... he drove it and didn't have the problem come back. What happened? He likely left a light on or something plugged into a non-switched outlet.

So I will go into a little more here in order to help you identify this. As others said, you could have a battery that is not good. The other items are a bad alternator that's not charging you properly, and finally parasitic drain.

First, check that your battery terminals are clean and the terminals are tight. When I installed some components on my gladiator, I didn't tighten down one of the terminals, and when I went to start it, it just died. I checked the terminals and found it was loose. I tightened it up, and she started right up. A loose terminal gives you voltage drop and the starter can't get all the amperage it needs.

The next step is to charge the battery up, either by using a battery charger, or jump it. Once its running and you have disconnected any charger, etc, you want to test that the alternator is doing its thing. Get a multi-meter and put it on the battery while its running. You should see higher than 14V. Anything less and its possible that you have a bad alternator. My gladiator shows 14.5-14.8V when its running.

Take the vehicle for a long drive and/or charge it with the charger until its full. You can then test the battery and the auxiliary battery. You can use a car battery tester which does a good analysis on the health of your battery. I use a cheap Topdon from Amazon. Its $50 and it has more than once saved me by diagnosing bad batteries on my autos, motorcycles, and generators. Link is here:

https://www.amazon.com/TT-TOPDON-AB101-Automotive-System+Charging/dp/B07DDDDSK9

If it says all is good for the aux and the main battery, your next step is to check for parasitic drain. I won't go into the details because there is an excellent write up here on how to do this:

https://www.wikihow.com/Find-a-Parasitic-Battery-Drain

If you follow the above steps, you should find your culprit.

Good luck! (or shall I say... Good skill!)

 

[Mjolnir]

This is incorrect... This was / is an issue, in regard to the majority of 2018 JL/JLU's (not 2019, 2020, 2021 vehicles) that have not had TSB 18-092-19 completed (Power Control Update).

Tell me why there are dozens on dozens of people who had issues and a new aux battery fixed their issue then?

I had my aux replaced SEVERAL times for failing, with nothing on or plugged in inside the cab so there was no "user error", before you attempt to go that route. It is most certainly correct. False statements like this do not help people.

 

[Mjolnir]

@Mjolnir

I have never implied that either of the 2 batteries cannot fail, etc.... or that replacing one or both batteries is not done as a "fix", lets say.

My earlier post that you reference was spot on...... as there was / is an issue, in regard to the majority of 2018 JL/JLU's (not 2019, 2020, 2021 vehicles) that have not had TSB 18-092-19 completed (Power Control Update).

The PCM update in question, amongst other things, changes the way the 2018, JL/JLU deals with startin in regard to the 2 two battery system.

In closing a 2018 JL/JLU owner that does not have TSB 18-092-19 , is making a mistake.

You stated it wasn't an issue. It is. It still is. It may not be as widespread as on 2018 JL's but it is still an issue.

 

[Deadeye]

I have had three batteries replaced myself, all tested bad. This last time, they repleaced both batteries, and that seems to be working now.

Pepe is the only one in the thread that made a connection to the TSB on the 18s. Regardless of whether its a system issue or just bad batteries, their is still an issue.

 

[ShadowsPapa]

So why is a TSB from 2019 related to ONLY 2018 model year WRANGLER in this mix? It's just going to confuse things. It's zero to do with the JT, nothing to do with 2019 and later model Jeeps and anything made since the 2018 model year will already have this PCM flash.....

SUBJECT: Flash: Powertrain Control Module (PCM) Updates
OVERVIEW: This bulletin involves reprogramming the PCM with the latest available software. MODELS: 2018 (JL) Jeep Wrangler

Customers may experience one or more of the following:
• Excessive blower fan noise when the A/C is on MAX output.
• Intermittent rough idle or idle surging, when coming to a stop (Automatic transmission equipped vehicles only).
• Random Electronic Stability Control (ESC) lamp illuminates in the Instrument Panel Cluster (IPC). • Driving at vehicle speeds while in first gear and shifting into neutral, a message 9Shift to 1st gear not allowed9 message appears in the Electronic Vehicle Information Center (EVIC) when conditions are not met (Manual transmission equipped vehicles only).
• 3 km (2 mph) difference between cruise set speed versus actual display speed.
• During cold vehicle operation and the use of cruise control on vehicles equipped with an automatic transmission, the engine RPMs may drop below idle speed while cruise control is engaged, this may occur if the customer presses the accelerator pedal to achieve a vehicle speed greater than the cruise control speed and then releasing it.
• Radio or IPC may reboot (flash off/flash on) during an Engine Stop Start (ESS) shutdown in cold conditions with a battery temperature below -12°C (10°F).

Above is a quote from that TSB. It won't have a place here with the JT since those are going to have the latest PCM as of the time they were built.

Dealerships are applying the latest PCM flash update anyway as JTs come in. IF your VIN is on their list, you are involved with a TSB the dealerships call a "recall", a preemptive fix.
So for the JT - this can pretty much be ignored.
My wife's GC was totally fixed with a battery replacement - BOTH. The dealer said they'd had a rash of Jeeps come in with bad batteries - both. (they were referring to the time period we went in, not the model year)
In her case they said both batteries tested bad. So it makes me wonder - if someone has problems with the lower battery, is the dealer shop stopping there and not giving the upper/main battery a good going over? My dealer does a test on your battery when you bring it in for anything. They caught the weak battery on my own GC even though it was starting and cranking beautifully, as good as ever, when it went in to the shop. Then 6 months later - the battery just suddenly failed. I looked back and months earlier they showed testing everything in detail (they even had the amount of brake lining and tire tread left filled in)

 

[ShadowsPapa]

I have had three batteries replaced myself, all tested bad. This last time, they repleaced both batteries, and that seems to be working now.

Pepe is the only one in the thread that made a connection to the TSB on the 18s. Regardless of whether its a system issue or just bad batteries, their is still an issue.

The solution is likely replace both. That's what my dealership did with my wife's Jeep. And that took care of all electric issues and ESS issues. Dealer shops need to do a thorough test of the main/upper battery even if it "appears" fine. Hers "appeared fine" but wasn't.
Replacing both made all issues go away.

 

[ShadowsPapa]

@ShadowsPapa

Yes, just changing out the ESS and the Main is a short lived remedy..... but then, you are at the first step of going through the issue again in the future and again....

About my post about the 2018 JL and how it is prudent to get the TSB done on a 2018.... Done so you aren't left stranded/no start situation when your ESS is partially depleted/depleted/dead..

Again, what's the 2018 TSB got to do with anything here in a JT forum?

And why is changing out the batteries in a JT just a short term fix?
The 2018 TSB shouldn't even be brought up as it's not related.
The JT has all of that already.

 

[Deadeye]

@ShadowsPapa

The mention of the 2018 JL and it was the one with the no start issue in question that does not impact the JT as you spew, was brought up , merely,as an informative, knowledgeable, reply to this post that had incorrect info in it.
https://www.jeepgladiatorforum.com/forum/threads/the-other-day-my-battery-died-and-i’m-trying-to-figure-out-why.38710/post-629152

Well my truck has been unable to start several times- once time because the ESS battery was defective and died, and another because it was the main. So yes, it will in fact leave you stranded.

 

[ShadowsPapa]

@ShadowsPapa

The mention of the 2018 JL and how it was the one with the no start issue in question, that does not impact the JT as you spew, was brought up , merely, as an informative, knowledgeable, reply to this post that had incorrect info in it.
https://www.jeepgladiatorforum.com/forum/threads/the-other-day-my-battery-died-and-i’m-trying-to-figure-out-why.38710/post-629152

And you ask "why is changing out the batteries in a JT just a short term fix?"

DAAAH, because if you don't drive enough to maintain charge in the battery(s) do not use a battery maintainer to maintain them and...... DAAAH, after 2-3 years when those replaced batteries age out / reach end of their life cycle, you will be replacing the 2 batteries again... and again in a cycle..

LOL - normal for ANY battery, not just these. So we are talking about people here with the JT that don't drive their truck more than a couple of times a month?
Odd, my Silverado was often left sitting - being driven only a couple of times a month, somtimes barely that. My Ford, even worse - that battery went over 12 years.
The batteries in my cars often sit months at a time. I from time to time put a tender on them but they normally go 5 to 6 years.

Smart ass - I asked why you said it was only a short term fix because that's all you said - "it's just a short term fix" then you go on about people who don't drive their trucks. These people obviously DO - some of them have more miles than I do - and they are having issues, while I am not. My truck sits for a week, sometimes more, at a time. No battery issues. A week or two isn't enough to cause an issue. I've proven that for decades. My wife's Jeep often sits for 2 or 3 weeks at a time, last fall was the very first time she's ever had any battery issues at all and the dealership blamed it on bad batteries. They'd seen a rash of them. Nothing to do with drivers or use.
If it was to do with trucks or other Jeeps sitting - we'd have a ton of issues as my wife put 13,000 miles on her Jeep in 2.5 years.
Mine sits a lot - no issues. I've got only a bit under 12K miles in over a year, many of those were a couple of long trips. It so far is fine.
I wonder of the people who have had issues with that aux battery - do they sit a lot? Doubt it - sounds like they are driven a lot, quite the opposite, yet they have multiple battery issues. Sounds like what my dealer said - "rash of bad batteries".
I'd suggest their dealer check BOTH batteries, not assume that when they find one bad, they stop there and replace just that one.
Interesting that when a couple of members have had both replaced, it seems to be ok now.
So you can't say it's a short term fix because they don't drive enough.

Sponsored