Jeep Garage  - Jeep Forum banner
1 - 18 of 18 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
I've inadvertently left our 2021 WK2, High Altitude in neutral over night and now have a dead battery. I park the Jeep on a plastic parking assistant in the garage and usually place in neutral until the vehicle stops rocking back and forth and then shift to park. Well, I left the car in neutral overnight and longer and now have a dead battery. My battery charger was showing a F01 code, "Internal Battery Short" and the battery would not take a charge. I placed the charger in "starter" mode and was able to enough energy to place the vehicle in park. It appears the battery is being successfully charged now and hopeful it will raise the battery enough to start the vehicle. evidently the battery will not charge will in park ??? Could I have done any damage to the vehicle we love so dearly. Any additional thoughts regarding this perdictament is greatly appreciated
 

·
Registered
2014 Summit 5.7 4wd 20" tires swapped to 18", added all skid plates
Joined
·
3,095 Posts
I've inadvertently left our 2021 WK2, High Altitude in neutral over night and now have a dead battery. I park the Jeep on a plastic parking assistant in the garage and usually place in neutral until the vehicle stops rocking back and forth and then shift to park. Well, I left the car in neutral overnight and longer and now have a dead battery. My battery charger was showing a F01 code, "Internal Battery Short" and the battery would not take a charge. I placed the charger in "starter" mode and was able to enough energy to place the vehicle in park. It appears the battery is being successfully charged now and hopeful it will raise the battery enough to start the vehicle. evidently the battery will not charge will in park ??? Could I have done any damage to the vehicle we love so dearly. Any additional thoughts regarding this perdictament is greatly appreciated
I'm not understanding why leaving it in neutral would discharge the battery. Nor can I think of a reason why the battery would not charge in park. I don't think you did anything that would be damaging to the vehicle but it's certainly possible something has gone wrong with some part of it, the battery or alternator or ???. Presumably your battery is a year old. That's a bit early for a battery to fail but I have had two batteries fail at the one-year point, so I know it happens.
 

·
Registered
Joined
·
4,564 Posts
I sort of agree with jimintempe^ why leaving the transmission in neutral would cause a dead battery.

But then again these new vehicles shift the transmission by electronics and not by old school mechanical linkage.
If this did drain the battery the only thing i can think of is the transmission module and maybe the PCM also were in an active state waiting for a gear shift drawing power from the battery.
If thats the case its a definite bug in the software.

Are you using an AGM capable battery charger?
Could be either the battery was so depleted it drew excessive amperage or the transmission was still in neutral drawing amperage.

Your history of batteries failing in a year could be because you don't take long enough drives for the alternator to adequately charge the batteries.
 

·
Registered
2020 Jeep Grand Cherokee Summit 3.6L 4x2
Joined
·
2,259 Posts
And don't forget you have TWO batteries on your 21 JGC.👍
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #8 ·
I sort of agree with jimintempe^ why leaving the transmission in neutral would cause a dead battery.

But then again these new vehicles shift the transmission by electronics and not by old school mechanical linkage.
If this did drain the battery the only thing i can think of is the transmission module and maybe the PCM also were in an active state waiting for a gear shift drawing power from the battery.
If thats the case its a definite bug in the software.

Are you using an AGM capable battery charger?
Could be either the battery was so depleted it drew excessive amperage or the transmission was still in neutral drawing amperage.

Your history of batteries failing in a year could be because you don't take long enough drives for the alternator to adequately charge the batteries.
Following further internet investigation I'm thinking I've suffered the Rear Lift Latch Battery Drain and dead battery not related to transmission gear placement. will have the vehicle towed to dealer tomorrow. Thoughts?
 

·
Registered
2014 Summit 5.7 4wd 20" tires swapped to 18", added all skid plates
Joined
·
3,095 Posts
Your history of batteries failing in a year could be because you don't take long enough drives for the alternator to adequately charge the batteries.
If that was from my comment... the two batteries I had that failed in a year, literally a year to the day, on both of them, were AC Delco some years back when that was the brand CostCo was selling. It was mindboggling.
 

·
Registered
Joined
·
4,564 Posts
If that was from my comment... the two batteries I had that failed in a year, literally a year to the day, on both of them, were AC Delco some years back when that was the brand CostCo was selling. It was mindboggling.
Yeah maybe, i fast read these posts and screw up a lot my bad.
I realize you live in the AZ heat thats hard on batteries but even so i'd think a battery should last longer than a year.

I still have the original factory AGM battery in my 20016 F150.
When i take it to the Ford dealership for an oil change they also check a bunch of other money making things of which includes the battery health.
A couple months ago had an oil change done there and they reported my 6 year old battery is still at 84%.
The only thing i can contribute that to is i never ever take short drives living out in the boon docks.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #11 ·
I've inadvertently left our 2021 WK2, High Altitude in neutral over night and now have a dead battery. I park the Jeep on a plastic parking assistant in the garage and usually place in neutral until the vehicle stops rocking back and forth and then shift to park. Well, I left the car in neutral overnight and longer and now have a dead battery. My battery charger was showing a F01 code, "Internal Battery Short" and the battery would not take a charge. I placed the charger in "starter" mode and was able to enough energy to place the vehicle in park. It appears the battery is being successfully charged now and hopeful it will raise the battery enough to start the vehicle. evidently the battery will not charge will in park ??? Could I have done any damage to the vehicle we love so dearly. Any additional thoughts regarding this perdictament is greatly appreciated
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #12 ·
I had the GC towed to a dealer who first responded with"there's an electrical short and we're trying to find where. Today they report back and indicate the battery had a dead cell and they replaced both batteries, no further reference to a "short". We'll pick the GC up in two days and i'll ask for a voltage check at that time.

I have a few questions:
1. Would a dead cell in the main battery also take out the battery for the stop/start system? I understand this GC has 2 batteries.

2. I would suspect if the battery had a dead cell and unable to be charged by the alternator warning lights would have indicated a problem, is this correct? recall the battery went dead after sitting for 24+ hrs which seems like a drain / short to me.

3. I would suspect the dealer done a diagnostic check when they started their investigation. Does the diagnostic results also show history, for over the past weeks?

I'm suspect there may still be electrical short somewhere and the dealer can't find it and not willing to tell the truth, copping out with a "dead cell". Yes, I'm suspicious of dealers, sales and repairs.
 

·
Registered
Joined
·
4,564 Posts
I had the GC towed to a dealer who first responded with"there's an electrical short and we're trying to find where. Today they report back and indicate the battery had a dead cell and they replaced both batteries, no further reference to a "short". We'll pick the GC up in two days and i'll ask for a voltage check at that time.

I have a few questions:
1. Would a dead cell in the main battery also take out the battery for the stop/start system? I understand this GC has 2 batteries.

2. I would suspect if the battery had a dead cell and unable to be charged by the alternator warning lights would have indicated a problem, is this correct? recall the battery went dead after sitting for 24+ hrs which seems like a drain / short to me.

3. I would suspect the dealer done a diagnostic check when they started their investigation. Does the diagnostic results also show history, for over the past weeks?

I'm suspect there may still be electrical short somewhere and the dealer can't find it and not willing to tell the truth, copping out with a "dead cell". Yes, I'm suspicious of dealers, sales and repairs.
Yeah i'm suspicious of dealer service depts. also.
Did you ask the tech him self who did the work exactly what he meant by an electrical short?
That could also be loosely interpreted as a shorted battery.
Need to be more pro active when it comes to auto service.

The important thing is to find out exactly what caused the battery to go dead or it could happen again.

My take right or wrong:
1. Since both batteries are sort of charged in parallel, a shorted cell in one of the batteries could of prevented the alternator from adequately charging the other battery deteriorating it, not sure about that or how the BMS would handle that situation.

2. Batteries don't like to be drained down to 0 volts. Once that happens they're usually never 100% the same again.
Did the dealership scan the PCM? Might of been a stored code there.
Before the battery drained down to nothing everything was good so no battery warning light.
Since the battery drained down to nothing overnight how could a battery warning light popup?

3. Depending on what scan tool they used, probably yes especially if the trouble code was stored.
Some trouble codes/CEL lights can clear them selves or after a certain number of drive cycles once the problem goes away.
Pretty sure a battery voltage warning is one of those.
 

·
Registered
2014 Summit 5.7 4wd 20" tires swapped to 18", added all skid plates
Joined
·
3,095 Posts
I had the GC towed to a dealer who first responded with"there's an electrical short and we're trying to find where. Today they report back and indicate the battery had a dead cell and they replaced both batteries, no further reference to a "short". We'll pick the GC up in two days and i'll ask for a voltage check at that time.

I have a few questions:
1. Would a dead cell in the main battery also take out the battery for the stop/start system? I understand this GC has 2 batteries.

2. I would suspect if the battery had a dead cell and unable to be charged by the alternator warning lights would have indicated a problem, is this correct? recall the battery went dead after sitting for 24+ hrs which seems like a drain / short to me.

3. I would suspect the dealer done a diagnostic check when they started their investigation. Does the diagnostic results also show history, for over the past weeks?

I'm suspect there may still be electrical short somewhere and the dealer can't find it and not willing to tell the truth, copping out with a "dead cell". Yes, I'm suspicious of dealers, sales and repairs.
1- It might. There have been a lot of threads in the past couple years of people with battery problems who had the two-battery setup. Many were only cured by replacing both batteries even though one of them seemed like it was still good.

2 - I don't think that's how it works. The alternator light comes on if the voltage output of the alt is lower than battery voltage. Even if the battery only has 11.9 volts you'll probably still be able to start the vehicle and as soon as it starts the alt will pump out 13 or more volts and try and charge the battery. I would not expect the light to come on. Same even if the battery got fully discharged and you jumped it to start it.

3 - The "dealer" is the tech who got assigned the vehicle. No telling what kind of diagnostic he might have gone thru. One of the problems here is when the battery goes bad/dead and the voltage drops too low it often causes all sorts of meaningless trouble codes to be set on multiple "computer modules". Might show "implausible cam position", or "voltage on O2 sensor out of range", etc. So if the battery is dead it can be pointless to start running "diagnostics" based on all the errant trouble codes caused by low battery voltage. From what I've seen most techs who get a vehicle which have a "bad" battery will first try to charge the battery and if it won't take a charge replace it, then clear the codes, then run the vehicle and see what pops up.
 

·
Registered
Joined
·
6 Posts
Thanks for this post. Although not related, I just had my battery die yesterday on my 2017 WK2, and I wasn't aware of the two battery configuration. Thanks to all in this thread for the helpful comments, I learned a lot. Pep Boys saved me after my dealer quoted $800 to fix my battery and two days or more to do it. Yes, you read that right, eight hundred dollars. Pep Boys was $240. Yikes! Good luck to the OP with their issue.
 

·
Registered
Joined
·
4,564 Posts
Thanks for this post. Although not related, I just had my battery die yesterday on my 2017 WK2, and I wasn't aware of the two battery configuration. Thanks to all in this thread for the helpful comments, I learned a lot. Pep Boys saved me after my dealer quoted $800 to fix my battery and two days or more to do it. Yes, you read that right, eight hundred dollars. Pep Boys was $240. Yikes! Good luck to the OP with their issue.
The one advantage of having a dealership doing the work is they generally use OEM parts.
But if out of any kind of extended warranty coverage then its the cheapest free for all fix.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #18 ·
The GC was brought home after having the dealer replace both batteries. The vehicle sat in the garage for 7+ days while we were away. Got home and the vehicle started fine, no other issues. Hopefully having the batteries replaced solved the problem.🤞
 
1 - 18 of 18 Posts
Top