Why did our 2019 leaf die (completely) overnight?

[handee]

This morning our 2019 leaf was nearly completely dead. We managed to open the driver side door with the electronic key and then everything went dark: power button does nothing at all.

We've summoned recovery however we are in a fairly remote area and expect the mechanic to take ages, and when they get here they won't know anything about electric cars. Our nearest Nissan dealership involves a day trip. So I am interested in trying to work out what the problem is.

Yesterday I drove the car for about 70 minutes in total, using about 15% of the main battery (up a big hill in the morning, then down a big hill again in the afternoon, if it matters that the battery was mostly used in the morning and in the afternoon it was mostly regen).

When I parked I didn't bother plugging it in, as the battery meter was still reading over 60%.

Does anyone have any theories as to what might have happened? Looking at other posts on this forum it seems it could be something to do with the 12v battery. However, I thought the 12v charged from what I think of as "the big battery" when the car is driving - and i did quite a bit of that just yesterday. I can't have left the car switched on, as it was locked and it won't lock if it's on.

 

[LeftieBiker]

The 12 volt battery is the most likely suspect, because of the complete power failure with plenty of charge in the traction battery. It may be defective, or it may have been chronically undercharged and just failed. Do you leave the car plugged in for many hours or days after charging ends? This, oddly enough,will often kill the 12 volt battery.

 

[handee]

The 12 volt battery is the most likely suspect, because of the complete power failure with plenty of charge in the traction battery. It may be defective, or it may have been chronically undercharged and just failed. Do you leave the car plugged in for many hours or days after charging ends? This, oddly enough,will often kill the 12 volt battery.

No we generally don't leave it plugged in. We have a "Zappi" charger which will charge the car from solar generation so we quite often charge at a low (1-2kw) rate, but the charger is around the side of the house and we're lazy, so only bother plugging the car in when a) it's a bit sunny and b) it needs a few bars.

 

[DaveinOlyWA]

The 12 volt battery receives boosts on a sort of schedule. Unfortunately that schedule does not seem to take into account the SOC of the battery. So any larger than "normal" demand between charges or challenging climate (too hot, too cold) will stress the 12 volt.

Your not plugging it in helped the 12 volt as plugged in or not, the schedule does not seem to change. The sad reality is this happens and my guess is additional demands on the 12 volt like telematics, use of the car in Accessory mode, or simply having the key fob in the near vicinity of the car can be a possible cause. Links below provide very few answers. Mostly just observations and those observations aren't good.

https://daveinolywa.blogspot.com/2021/03/february-2021-drive-report-more-12-volt.html

https://daveinolywa.blogspot.com/2021/01/leaf-12-volt-battery-health.html

 

[SageBrush]

In approximate order:

1. 12v drained from a load overnight. Check lights and doors
2. Bad 12v battery -- replace
3. Wiring problem. Having just an hour ago had rodent damage repaired, it is on my mind
4. Defective 12v converter

I suggest starting with the simple stuff and approach: After you are sure that there are no 12v loads, trickle charge the 12v battery (probably for the better part of 12 hours.) If the 12v drains again or is weak, replace it. If it drains with a new 12v that has been properly trickle charged to full, seek help

 

[LeftieBiker]

If/when you do replace the 12 volt battery, I strongly suggest that you get an AGM (absorbed glass mat) type lead-acid battery. These batteries tolerate being partially discharged better, and they seem to take a charge better when used in a Leaf. The correct group number is 51R - and don't forget the "R" or the cables won't reach the terminals. Make sure the new battery is fully charged either before or right after installation.

 

[Learjet]

Forgive me if this has been mentioned already... the car charges the 12 volt battery when you are charging the traction battery. So it would also stand to reason the more you use the car (drive) that equals more time the 12 volt battery gets charged while in use...but the 12 volt battery also gets more charging time by the increase time spent charging the traction battery. So to recap, if you drive more...the 12 volt battery gets more charging time on the road and when plugged in recharging which is better for the 12 volt battery life.

 

[HerdingElectrons]

This morning our 2019 leaf was nearly completely dead. We managed to open the driver side door with the electronic key and then everything went dark: power button does nothing at all.

When I parked I didn't bother plugging it in, as the battery meter was still reading over 60%.

Does anyone have any theories as to what might have happened? Looking at other posts on this forum it seems it could be something to do with the 12v battery. However, I thought the 12v charged from what I think of as "the big battery" when the car is driving - and i did quite a bit of that just yesterday. I can't have left the car switched on, as it was locked and it won't lock if it's on.

I had the same thing happen to me on my 2018 about 18 months into ownership. Drive the car almost daily and the next day it was just dead. My situation was similar in that the traction battery was high enough that I didn't charge it that night.

I have a 12V charger & charging the 12V battery solved the problem for a few month but a new battery was required and was replaced under warranty and the new 12V battery is already falling below voltage so I am charging the battery monthly to extend its life & will ultimately replace with a AGM or a Lithium 'race' battery when the time comes.

 

[handee]

Forgive me if this has been mentioned already... the car charges the 12 volt battery when you are charging the traction battery. So it would also stand to reason the more you use the car (drive) that equals more time the 12 volt battery gets charged while in use...but the 12 volt battery also gets more charging time by the increase time spent charging the traction battery. So to recap, if you drive more...the 12 volt battery gets more charging time on the road and when plugged in recharging which is better for the 12 volt battery life.

Does this mean that if we were to be able to open the front charging port and plug it into the house, it'd charge the 12v battery assuming that can hold charge?

(This is at the moment academic as we cannot open the front charging port and Nissan Recovery tell us that replacing the battery ourselves will void the warranty. So we're waiting for someone to come and take the car to a Nissan dealer 1h40 drive away. However, when they turn up with the tow truck/flatbed they're going to be unable to get the car off the drive as the front wheels won't turn without engaging the drive battery, so working out how to charge it enough to be able to reverse the car off the drive is probably useful.)

 

[LeftieBiker]

Replacing the 12 volt battery won't void the warranty on the car. It will void the warranty on the now-dead 12 volt battery, and on any components you might damage while replacing it. Plugging the car in may give the car enough of a charge to revive the 12 volt battery, but I rather doubt it, I'm afraid. Still, you can look on YouTube for how to open the charge port the hard way, assuming that it's possible with the hood also unable to open. Actually, scratch that. You can use the mechanical key inside the key fob to open the car's door, then release the hood manually as usual, then try the manual charge port release.

 

[DaveinOlyWA]

Forgive me if this has been mentioned already... the car charges the 12 volt battery when you are charging the traction battery. So it would also stand to reason the more you use the car (drive) that equals more time the 12 volt battery gets charged while in use...but the 12 volt battery also gets more charging time by the increase time spent charging the traction battery. So to recap, if you drive more...the 12 volt battery gets more charging time on the road and when plugged in recharging which is better for the 12 volt battery life.

There is no evidence that more driving creates more charging opps for the 12 volt. When you are driving, the 12 VDC is in two states; normal at 13ish volts or charge mode at 14.4ish volts. Only charge mode adds to storage energy in the 12 volt. Now, you can "force" charge the battery by turning on windshield wipers or at least raise the DC system voltage to charge level. Use LEAF Spy to monitor the current to determine the likelihood of the battery actually being boosted.

See my link above. I ran experiments nearly all winter and was able to add at least 5-10 more minutes of forced charge after the LEAF's "automated" charge had completed nearly every day.

But there is no doubt that the LEAF cannot or does not care to monitor the 12 volt, nor does it ever "top it off" so the apparent issue seems to be how much the 12 volt is used between boosts.

 

[jjeff]

..... with the hood also unable to open. Actually, scratch that. You can use the mechanical key inside the key fob to open the car's door, then release the hood manually as usual, then try the manual charge port release.

Yes you got it right in your second sentence but what I haven't found a way to do is open the hood if the manual hood release doesn't work
My brother's '13S Leaf hood release cable isn't able to release the hood, we tried everything including pushing/banging the hood down while pulling on the release. We also tried putting our fingers under the hood with the charge port closed and open, nothing seems to release the hood. I even tried pulling on the cable with a needle nose pliers, all to no avail.
The whole thing started with a panic call that he had left the blinkers on for about a half-hour and the car wouldn't start. I suggested he get a jump start or put the 12v battery on a charger but he didn't have a 12v charger and said he couldn't open the hood. He said he had been having problems opening the hood the last couple times he had to add WW fluid but it always opened, now it wouldn't.
I came equipped with jumper cables, a 12v lithium jump starter and something I had bought a few years back but never used, a cigarette to cigarette lighter jump starter cable.
I was also unable to get the hood open, short of using a wonder bar and destroying the hood in the process. As I couldn't get the hood open the 12v chargers that attach directly to the battery wouldn't work but I did end up having luck with my lighter to lighter jump starter. That wasn't as easy as one would hope either as the Leaf lighter socket isn't hot when the Leaf is off and it wouldn't start correctly with it's low battery but it did power up enough to power the socket. I left the car on with the cable connected between his vehicle and mine for a few minutes, I then turned off the Leaf and then restarted it. It took a couple pushes of the power button with my foot on the brake but finally the Leaf came to life with the double green arrows and ready to go. I had him leave it on with the windshield wipers on, intermittent and was hoping that would be enough to charge the 12v fast as possible. I've read here that running the WW will cause the 12v battery to charge faster than not turning on the WW motor but again wasn't sure if intermittent would be as good as ON constantly but figured it wouldn't hurt.
Last weekend I played with my '13S trying to see how I could open the hood if the cable release didn't work but was again unsuccessful. I tried a few tips I read on MNL, one being going through the charge port area but I couldn't figure a way of removing the plastic insert without destroying it. I was able to remove it by opening the hood and removing the large plastic cover under the front part of the hood and then the plastic liner inside the charge port area but even with both covers gone I couldn't get to the hood release area to manually manipulate the release, metal supports were in the way.
Long story short his hood is still stuck down and I have no idea, short of destroying his hood, to get it open from the outside. He's going to come over this weekend and I'm going to try the needle nose pliers and really pull on the cable, hard enough to either release the hood or break the cable, not much to lose at this point, he'll have to be able to get the hood open to be able to replace the original 12v battery. I told him if pulling the cable doesn't work he might have to take it into Nissan, maybe they'll have a special tool to do it. Can't believe they'll have to destroy the hood but who knows.

 

[Learjet]

Forgive me if this has been mentioned already... the car charges the 12 volt battery when you are charging the traction battery. So it would also stand to reason the more you use the car (drive) that equals more time the 12 volt battery gets charged while in use...but the 12 volt battery also gets more charging time by the increase time spent charging the traction battery. So to recap, if you drive more...the 12 volt battery gets more charging time on the road and when plugged in recharging which is better for the 12 volt battery life.

There is no evidence that more driving creates more charging opps for the 12 volt. When you are driving, the 12 VDC is in two states; normal at 13ish volts or charge mode at 14.4ish volts. Only charge mode adds to storage energy in the 12 volt. Now, you can "force" charge the battery by turning on windshield wipers or at least raise the DC system voltage to charge level. Use LEAF Spy to monitor the current to determine the likelihood of the battery actually being boosted.

See my link above. I ran experiments nearly all winter and was able to add at least 5-10 more minutes of forced charge after the LEAF's "automated" charge had completed nearly every day.

But there is no doubt that the LEAF cannot or does not care to monitor the 12 volt, nor does it ever "top it off" so the apparent issue seems to be how much the 12 volt is used between boosts.

I have a voltage usb/voltage meter in the 12 volt socket, so I see the voltage all the time. I have seen it only 1 or 2 times go to 14.4 volts for a breif time while driving and the wipers were off. Maybe more rain=more wipers=more 14.4 time=better 12 volt battery life. I think even at 12.9 to 13.1 volts I see on the meter, the battery is still getting a trickle charge.

 

[nlspace]

Yea but a trickle charge at 12.9 or 13.1 doesn't desulfate the plates. That's why laef batteries wear out and fail so early and often.

 

[Stanton]

Yea but a trickle charge at 12.9 or 13.1 doesn't desulfate the plates. That's why Leaf batteries wear out and fail so early and often.

It's not just "Leaf batteries": it's all 12v lead acid batteries. I'm still amazed how much activity (no pun intended) the 12v starter battery gets on this Forum!
Here are the facts, because I have a battery monitor permanently connected to my 12v battery (see sig): the traction battery (via a DC converter) cycles the starter battery between 12-14v at 15 minute (or so) intervals when driving and charging--except when the windshield wipers are on when there is a constant 14v (actually more like 14.4v). For example, you can "jump the car" to plug in an EVSE and get the same charging cycle on the 12v battery that you get if you "jump the car" to turn it on. Of course, that doesn't do any good if the 12v battery is shot (but it will keep the traction battery from running down).
The bottom line is: don't mess around with a marginal 12v battery and just replace it...and replace it with a Lithium version if you don't ever want to worry about it again (see sig).

 

[DaveinOlyWA]

Forgive me if this has been mentioned already... the car charges the 12 volt battery when you are charging the traction battery. So it would also stand to reason the more you use the car (drive) that equals more time the 12 volt battery gets charged while in use...but the 12 volt battery also gets more charging time by the increase time spent charging the traction battery. So to recap, if you drive more...the 12 volt battery gets more charging time on the road and when plugged in recharging which is better for the 12 volt battery life.

There is no evidence that more driving creates more charging opps for the 12 volt. When you are driving, the 12 VDC is in two states; normal at 13ish volts or charge mode at 14.4ish volts. Only charge mode adds to storage energy in the 12 volt. Now, you can "force" charge the battery by turning on windshield wipers or at least raise the DC system voltage to charge level. Use LEAF Spy to monitor the current to determine the likelihood of the battery actually being boosted.

See my link above. I ran experiments nearly all winter and was able to add at least 5-10 more minutes of forced charge after the LEAF's "automated" charge had completed nearly every day.

But there is no doubt that the LEAF cannot or does not care to monitor the 12 volt, nor does it ever "top it off" so the apparent issue seems to be how much the 12 volt is used between boosts.

I have a voltage usb/voltage meter in the 12 volt socket, so I see the voltage all the time. I have seen it only 1 or 2 times go to 14.4 volts for a breif time while driving and the wipers were off. Maybe more rain=more wipers=more 14.4 time=better 12 volt battery life. I think even at 12.9 to 13.1 volts I see on the meter, the battery is still getting a trickle charge.

no...not even a trickle... The charge must be sufficient to create current flow which means a difference of potential. Yes, it "can" happen but not in this circumstance. The electronics are simply not designed for that. The 12 volt is essentially disconnected from the system at 13 volts.

 

[handee]

I'm just back from the Nissan garage 2h drive away with a new 12v battery. Replaced under warranty, and so not one I had any control over (that is, not one of the varieties recommended here on the forum). They don't think there is anything else draining the battery - that is, the technicians didn't find anything else wrong. So the explanation is that a 20-month old battery just "wore out" overnight with no prior warning.

Question #2 for the experts here: given that the battery wore out pretty fast... is there anything I can do to preserve this one? What's the best way to monitor battery health?

For starters, I will be purchasing a battery charger tomorrow.

 

[jjeff]

Periodically putting it on a trickle type of charger and for as long as you can is the best thing you can do for battery health. Note you don't need a large battery charger, a small trickle charger is best and preferably one with a float type feature so if you do leave it on the charger for an extended period of time, you won't boil your battery dry.
I try and put my battery on such a charger maybe once/week and overnight but at times it goes 2 or even 3 weeks between top-ups and knock on wood I haven't been stranded. This is for my '13, in my '12 I put an Optima yellow top AGM type battery several years ago, it was purchased used and I don't know what the previous owner did, it started acting up a couple of years after picking it up so I purchased the Optima and like my '13 haven't had any issues.

 

[Stanton]

Question #2 for the experts here: given that the battery wore out pretty fast... is there anything I can do to preserve this one? What's the best way to monitor battery health?

No: not if it's the same crummy battery.
I would replace that "free" 12v battery with something better (plenty of suggestions in this thread) before you have to make that 4 hour (round trip!) trek to replace it again...but that's just me.

 

[DaveinOlyWA]

I'm just back from the Nissan garage 2h drive away with a new 12v battery. Replaced under warranty, and so not one I had any control over (that is, not one of the varieties recommended here on the forum). They don't think there is anything else draining the battery - that is, the technicians didn't find anything else wrong. So the explanation is that a 20-month old battery just "wore out" overnight with no prior warning.

Question #2 for the experts here: given that the battery wore out pretty fast... is there anything I can do to preserve this one? What's the best way to monitor battery health?

For starters, I will be purchasing a battery charger tomorrow.

Get LEAF Spy; helps to monitor charging activity to the 12 volt

Charge every day; Roughly a a third of dead 12 volt incidents were from people who had their car sitting more than 24 hours with no driving, no charging. I ran experiments and the amount of "forced charging" was greatly reduced when I charged every day (due to limited use, I was only charging 80-90 mins a day)

Note; What is seemingly a much lesser issue is when the car is parked somewhere for extended periods of time. I have parked mine at the airport or such several times w/o issues as have many others. Why is this ok or at least "better?" My guess is the proximity of the fob that the car detects and wakes the car up increasing the load on the 12 volt. No real way of testing this. Another thought I had was telematics and the likelihood that a public parking spot may have a better cellular signal than a personal garage but in monitoring cars with and w/o issues, telematics didn't seem to play a part?

Force charging; As we know, the DC system voltage is boosted to 14.4ish volts when the windshield wipers are on. With LEAF Spy, you can monitor the current so I was in the habit of force charging a few times a week. The system current is below .25 amps forced charging is not likely happening. I experimented with every possible accessory combo I could think of to see how it affected the current and saw minimal if any effects.

However, when force charging and seeing .75 amps and higher, its fairly certain charging is happening. I normally force charged until the current dropped below one or when I arrived at work. Yeah, sometimes 17-20 minutes was not enough time...