My thoughts on the auxiliary battery

[The Sigma]

Eleven days ago I opened a thread regarding the ESS and a video Scotty Kilmer released. It was quickly apparent that Scotty is a polarizing individual to say the least. At any rate, that post was the tail end of me searching for answers to something I saw - the story behind that post was the voltage spikes I was noticing in my Gladiator. It consistently went as high as 14.9v. Pure happenstance that I was flipping though my menus one day and saw it. I mean what person drives around with the battery voltage screen display on their console?

I'm sharing my observations on my own Gladiator. The thought behind it is that the normal operating range fluctuates between 12.3-ish to 14.5-ish. If it stays below the 12.3 range when not being called to use, the aux (or main) battery is on it's way out; if it stays above the 14.5 range the alternator is having to work extra hard to bring up the charge to maintain things.

The route I chose to go with was to disconnect the aux negative cable and pull fuse 42. My observation? Voltage immediately dropped and hovered in the 14.2-ish range. What does that tell me? The aux battery was likely dying or dead and causing extra stress on the main. At the moment, my main seems to be ok.

The take away? Had I not watched my voltage for a number of days, I would have never of known the stress my electrical system was under. Everything was working normally. I'm suspecting the stories we've all come across about where someone goes out and their normal functioning Gladiator was suddenly dead one day is likely something that did present plenty of warning signs and could have been prevented had it been observed in time.

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[Lost1wing]

I look at it this way. I look at the ess page often. If It says ready, I assume the aux is good. If it says battery charging for most or all of my trip, the aux is low( in need of a charge and IBS reset). If it says service ess, time to look for faults. Maybe both batteries need help. I haven't been down that road yet.

I think removing the aux and pulling the fuse puts you in a worse position. It does save you the expense of the second battery though. I see your point of the aux dragging the main down, but it is very easy to view the ess page and look for a ready status.

 

[The Sigma]

I look at it this way. I look at the ess page often. If It says ready, I assume the aux is good. If it says battery charging for most or all of my trip, the aux is low( in need of a charge and IBS reset). If it says service ess, time to look for faults. Maybe both batteries need help. I haven't been down that road yet.

I think removing the aux and pulling the fuse puts you in a worse position. It does save you the expense of the second battery though. I see your point of the aux dragging the main down, but it is very easy to view the ess page and look for a ready status.

Really is food for thought and part of the learning curve I guess. Sharing my observation and (on my part) largely speculation. We typically see that if the battery is the issue to always replace both. One is a humungous battery, the other looks like it should be in a lawn mower. Lol. Makes me wonder if is indeed the small one that gives out first and the issue isn't caught until it wipes out the big one as well creating the necessity to replace them both.

 

[Mr._Bill]

Really is food for thought and part of the learning curve I guess. Sharing my observation and (on my part) largely speculation. We typically see that if the battery is the issue to always replace both. One is a humungous battery, the other looks like it should be in a lawn mower. Lol. Makes me wonder if is indeed the small one that gives out first and the issue isn't caught until it wipes out the big one as well creating the necessity to replace them both.

It's a crapshoot. Depends largely on the quality of the installed battery. My Main battery went first, and the Aux battery went six months later, but didn't get replaced until a year after the main died.

 

[Lost1wing]

I ha

Really is food for thought and part of the learning curve I guess. Sharing my observation and (on my part) largely speculation. We typically see that if the battery is the issue to always replace both. One is a humungous battery, the other looks like it should be in a lawn mower. Lol. Makes me wonder if is indeed the small one that gives out first and the issue isn't caught until it wipes out the big one as well creating the necessity to replace them both.

I have a 2020. I am still on my original batteries. I think my Jeep started out with dead batteries at the dealer. The wife saw it and had to have it. She test drove it and was told the Jeep sat too long and they needed to jump start it. They said it will be fine after a few miles. That worked fine for that test drive. ESS was not mentioned or tested. We came back a few days later to pick up the Gladiator. ESS was working at the time. 3 or 4 months later, no ESS. I tossed on a 12v lead acid charger on it for a while and it was working again that afternoon.

After owning it for a year, I disconnected the main battery to do some electrical work. It was then that I learned that I had a second battery, and it is still hot with the main disconnected. I didn't finish the work I had planned to do until the next morning. I connected the main and tried to start her up. All the dash lights were on and I wasn't seeing any fault lights. I put the lead acid charger on it again and went in to do some research. So I essentially had a dead aux and a charged main. Had I gone to the ESS page at that time it would have said Start Stop unavailable perhaps. I went back out a few minutes later and it fired up.

Now the ESS was not functioning as advertised. It would take an hour or so of driving to get the ready message.

Last winter or early spring I was thinking about replacing my aux and main, until I read a post from ShadowsPapa. He mentioned AGM batteries/chargers/IBM. I did the recommended and I'm still on the original batteries and the ESS ready message is displayed right after warm up.

I'm pretty handy around cars but to be honest. This is my first with ESS and AGM batteries. If it wasn't for this forum, I'd have two new batteries and no clue how ESS works.

 

[Lost1wing]

It's a crapshoot. Depends largely on the quality of the installed battery. My Main battery went first, and the Aux battery went six months later, but didn't get replaced until a year after the main died.

Who knows how many times your JT had to be jumped off if any , before you took possession. Was it dead flat for a week/month? Just my thought on our batteries.

 

[Mr._Bill]

Who knows how many times your JT had to be jumped off if any , before you took possession. Was it dead flat for a week/month? Just my thought on our batteries.

I bought in July 2019, and it was the one being used for test drives. I don't think that was an issue for my truck, but I can see where it would be a problem for many.

 

[Stan H]

ESS page ??

 

[Lunentucker]

I guess I should consider replacing the 5 year old OEM battery in the Subaru at some point, eh?

Jeep doesn't make batteries, good ones or bad ones.
Last time I looked there were about three major vehicle battery makers in the world, and they account for ~90% of all OEM and otherwise store branded batteries.
I doubt Mopar sends them engineering designs on how to make batteries for them. They probably already have a team.

What Jeep does make - shitty electrical systems that have parasitic draws, and that marry your main cranking battery to a lawn mower battery that's mounted in an impossible location for emergency service and replacement.

Solution? - See first post, but sans the video from the epileptic speed junkie on energy drinks. Jesus Christ! What is wrong with that guy?! Can we bring lobotomies back?

When I made this simple video I thought that taking the AUX battery offline would disable ESS. That part is wrong, but I don't feel like making another video. Others have done it already.
Meh. Press Start button / Press ESS button. It's muscle memory now.
The rest is accurate, simple, and really easy to do.

As I see it, I had two choices. Take care of it on my terms, or deal with it on its terms, at a time and place of epic inconvenience.
I chose the former.
You do you.

 

[sharpsicle]

Based on your story and the results after disconnecting the aux battery, I do wonder if you’ve actually got a main battery on its way out rather than having removed the problem. I think you’ve just rearranged the issue and it simply looks different now.

As convenient as the dash voltage readout is, it’s no replacement for actually testing the batteries. Everyone likes to complain about the system, but the system isn’t the problem it’s the batteries. Seeing an issue with the system is just a sign that diagnostics are needed. It’s not a replacement for said diagnostics.

 

[Andy29847]

I guess I should consider replacing the 5 year old OEM battery in the Subaru at some point, eh?

Jeep doesn't make batteries, good ones or bad ones.
Last time I looked there were about three major vehicle battery makers in the world, and they account for ~90% of all OEM and otherwise store branded batteries.
I doubt Mopar sends them engineering designs on how to make batteries for them. They probably already have a team.

True but misleading. The batteries are labeled as Mopar. I'd guess that they are made to Mopar specs or maybe Mopar specifies the quality of the batteries and chooses from existing selections. As an example, Interstate sells 4 versions of their H^ battery.

 

[stuckindeep]

Eleven days ago I opened a thread regarding the ESS and a video Scotty Kilmer released. It was quickly apparent that Scotty is a polarizing individual to say the least. At any rate, that post was the tail end of me searching for answers to something I saw - the story behind that post was the voltage spikes I was noticing in my Gladiator. It consistently went as high as 14.9v. Pure happenstance that I was flipping though my menus one day and saw it. I mean what person drives around with the battery voltage screen display on their console?

I'm sharing my observations on my own Gladiator. The thought behind it is that the normal operating range fluctuates between 12.3-ish to 14.5-ish. If it stays below the 12.3 range when not being called to use, the aux (or main) battery is on it's way out; if it stays above the 14.5 range the alternator is having to work extra hard to bring up the charge to maintain things.

The route I chose to go with was to disconnect the aux negative cable and pull fuse 42. My observation? Voltage immediately dropped and hovered in the 14.2-ish range. What does that tell me? The aux battery was likely dying or dead and causing extra stress on the main. At the moment, my main seems to be ok.

The take away? Had I not watched my voltage for a number of days, I would have never of known the stress my electrical system was under. Everything was working normally. I'm suspecting the stories we've all come across about where someone goes out and their normal functioning Gladiator was suddenly dead one day is likely something that did present plenty of warning signs and could have been prevented had it been observed in time.

I had an issue with a JKU some years back the battery drained after sitting several weeks. The dealer could not find the issue after several tries. They replaced the battery, but it did not help. I know there is a constant drain on the battery due the electronics on all vehicles mainly the ECU.

So being a controls technician I set up my true RMS meter to monitor systems. Once set up I started recording the voltage and amps on my computer. Then I started pulling fuses and noted the readings. Then finally I pulled the fuse to the gauge cluster and the readings jumped up. I then broke out the electrical schematics in the OEM shop manual. Based on tracing the circuits there should not be any voltage or amperage draw from the gauge cluster when the vehicle is off.

I printed out my readings and went to the dealer and discussed with them that I have found. They then took the info to their head electrical trouble shooter. He agreed with my findings, and they ordered a new gauge cluster under warranty.

 

[Lunentucker]

True but misleading. The batteries are labeled as Mopar. I'd guess that they are made to Mopar specs or maybe Mopar specifies the quality of the batteries and chooses from existing selections. As an example, Interstate sells 4 versions of their H^ battery.

Interstate Battery System of America, Inc., a.k.a. Interstate Batteries, is a US privately owned battery marketing and distribution company. It markets automotive batteries manufactured by Brookfield Business Partners, Exide Technologies, and others through independent distributors

 

[JW Jeep]

I had an issue with a JKU some years back the battery drained after sitting several weeks. The dealer could not find the issue after several tries. They replaced the battery, but it did not help. I know there is a constant drain on the battery due the electronics on all vehicles mainly the ECU.

So being a controls technician I set up my true RMS meter to monitor systems. Once set up I started recording the voltage and amps on my computer. Then I started pulling fuses and noted the readings. Then finally I pulled the fuse to the gauge cluster and the readings jumped up. I then broke out the electrical schematics in the OEM shop manual. Based on tracing the circuits there should not be any voltage or amperage draw from the gauge cluster when the vehicle is off.

I printed out my readings and went to the dealer and discussed with them that I have found. They then took the info to their head electrical trouble shooter. He agreed with my findings, and they ordered a new gauge cluster under warranty.

Ya My Brother had this problem on a older Dodge Ram pickup a few Years ago. We new it had a draw but had a hard time finding it. It was the Gauge cluster and it was an expensive item to replace. I remember I googled it and there were others with the same problem.

 

[Lost1wing]

The parasitic draw isn't really a flawed electrical design. It is the next generation owners and or designers coming up with more demands on the electrical systems.

In 1966 and you turned the key off the car was dead with the exception of the dome light. It went off when the doors closed. Well, it had an analog clock.

Later years added alarms. Then lights remain on then the body modules remained on for a period. More wireless gadgets were added. Now, computers in some just stay on. The demand for power is outrageous all to make you feel good. It all comes with a price and that is battery life.

I just replaced an original battery in a 2005 tractor. That battery has one function and that is to start the tractor. It may be a different battery than that of a car battery but 18 years is pretty good.

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