Leaf dies while driving

[IalexI]

Dear forum members

I had a very scary event yesterday on the highway. While being in cruise mode at 50 mph on a flat surface, the car simply switched itself off. In the screen, there was no error message, but only the usual stuff you see when switching it off by the button ("charging timer: on" etc). The car kept rolling in neutral and I couldn't accelerate anymore. I tried to restart the car while it was still rolling. I could turn it on, but couldn't get it out of neutral. I then took the next exit, came to a full stop and could restart the car successfully.

Here is some additional information (please feel free to ask whatever is relevant):
- mileage 75000 miles
- SOC during event: about 50%
- constant speed (50 mph cruise mode on), low load on motor
- B mode, Eco
- SOH 79.11%, Hx 69%
- battery temperature about 77 Fahrenheit
- voltage of 12v battery according to leaf spy: 13V
- no heater/AC etc were on, only the LED headlights

Any ideas what could be going on?

 

[Minoxer]

What year and model is your Leaf?

 

[IalexI]

It's a late 2013 SL.

 

[BrockWI]

That is really strange. My only guess is if your 12v has a loose connection and maybe it vibrated or bounced enough to disconnect for a second that might explain it. It won't "restart" while in gear or neutral, it wants to be in park but I wouldn't recommend putting it in park while your rolling. So it makes sense not restarting while in neutral or rolling.

 

[Stanton]

Without any codes/DTCs, there's no way to tell. However, since you were on the highway (and the battery pack is degraded due to age), it's possible there are some weak cells. The only way to know is post a LeafSpy cell-pair voltage graph (and the lower the SOC the better).

 

[azzipEVoli]

Hi IalexI, I have a similar experience to what you describe. I know how awful it feels! Huh! Please be careful and safe.

First: Have you checked your vehicle for open recalls with the vehicle's VIN? Recalls | NHTSA

My car is currently at a local dealership service center for diagnosis. The sudden shutting-off issue was getting dangerously worse, frequent, total, and it happened randomly at any speed. Rebooting the vehicle over and over and avoiding highways were no longer an option (a.k.a. avoiding the problem!). Your post inspired me to share my story here: 2014 Leaf S random sudden shut-off

In my case, replacing the 12v battery was never a solution. The codes may have be misleading and, according to the dealership I'm working with, the solution they offer is not only unaffordable but... simply not available!

I hope that your issue will turn out to be minor and that it can be fixed at a low cost to you. I wish you the best.

 

[IalexI]

Please find the DTCs attached as read shortly after the incident. I have reset the codes and after driving a few miles nothing has popped up so far.

I believe I don't have weak cells. I will post a voltage distribution graph when the SOC is low.

 

[hradek]

Solar flares?

 

[TobyHolland]

Dear forum members

I had a very scary event yesterday on the highway. While being in cruise mode at 50 mph on a flat surface, the car simply switched itself off. In the screen, there was no error message, but only the usual stuff you see when switching it off by the button ("charging timer: on" etc). The car kept rolling in neutral and I couldn't accelerate anymore. I tried to restart the car while it was still rolling. I could turn it on, but couldn't get it out of neutral. I then took the next exit, came to a full stop and could restart the car successfully.

Here is some additional information (please feel free to ask whatever is relevant):
- mileage 75000 miles
- SOC during event: about 50%
- constant speed (50 mph cruise mode on), low load on motor
- B mode, Eco
- SOH 79.11%, Hx 69%
- battery temperature about 77 Fahrenheit
- voltage of 12v battery according to leaf spy: 13V
- no heater/AC etc were on, only the LED headlights

Any ideas what could be going on?

I see this very often on cars that are brought to me for a #LeafBatteryUpgrade......it happens when 1 or more if the cells is very badly degraded - asking for too much power from a pack with a cell/cells like this causes the pack to shut off when any one cell reaches it's minimum voltage.
The good news is that switching off for 5 minutes allows a safe restart - on many tired packs I evaluate, just driving gently, if the pack hasn't yet shut off, often gives the weakest cell(s) the chance to equalise enough to allow moderate progress

 

[MikeinPA]

Solar flares?

https://www.bbc.com/future/article/20221011-how-space-weather-causes-computer-errors

 

[IalexI]

As promised, a screenshot from leaf spy pro with SOC 18%.

I tried to put maximum load on the battery at this charging level (maximum acceleration for a few seconds) and observed no issues.

 

[MozzoAU]

Looking at the SOC graph, that's a pretty healthy battery, unlikely IMO to be a traction battery issue based on that screenshot.

Looking at the DTC's there are two low voltage related messages. I'd also investigate the PDU module DTC's.

Has the 12v battery been replaced? Has the car drained the 12v battery completely in recent weeks?

Moz

 

[IalexI]

Many thanks for the analysis!

I just recently bought the car, so I unfortunately cannot answer the question how old the 12V battery is.

However, due to travels, I didn't move the car for about 2 weeks, which might have drained the battery.

Could you please elaborate more on the PDU module?

I read the DTCs again yesterday evening (after about 50 miles of driving following the reset) and everything was fine.

 

[themr23]

As promised, a screenshot from leaf spy pro with SOC 18%.

I tried to put maximum load on the battery at this charging level (maximum acceleration for a few seconds) and observed no issues.

10 mV at low SOC on a 70% Hx battery seems unreal

 

[IalexI]

@themr23 At which value is the Hx concerning?

 

[MozzoAU]

The car being left idle for 2 weeks can contribute to the 12v battery being quite low. This causes all sorts of issues.The Nissan Leaf is notoriously poor at managing the health of the 1212v battery. The factory supplied battery is not able to handle being discharged deeply. If in doubt, swap out with a decent deep cycle version.

 

[SteveDK]

This is a problem that is not unique to the Leaf. We have trouble with our 2020 RAV4 Hybrid not charging its 12 battery enough. We use a battery maintainer to keep that charged up. I have not had trouble with my 2023 Leaf SV+ yet, but I do have a 2X 27 mile commute. It seems like many car designers are not planning for shorter commutes, and not building in some kind of battery maintenance charging for the 12 V battery when the car is not being used. It should be possible, I would think, to have a built in battery maintainer for EVs and hybrids.

 

[themr23]

@themr23 At which value is the Hx concerning?

I was expecting more mV difference at that Hx at lower SOC. Is the mV higher nearer to full charge?

 

[IalexI]

Hi there

I just wanted to report back to the forum after driving about 2000 miles.

The car is driving perfectly fine and the issue has not reoccurred. I really wonder if it might have been user error (maybe I pushed on the on/off button with my knee?).

At least until now everything is fine! I will report back if I should encounter the problem again.

Greetings
Alex

 

[cornbinder89]

Hi there

I just wanted to report back to the forum after driving about 2000 miles.

The car is driving perfectly fine and the issue has not reoccurred. I really wonder if it might have been user error (maybe I pushed on the on/off button with my knee?).

At least until now everything is fine! I will report back if I should encounter the problem again.

Greetings
Alex

Thanks, it helps everyone when someone reports back, good or bad, it helps future diagnosing. It is discouraging not to get a definitive answer to what caused it. Thanks again.