We got towed last night (battery failure at 10% SoC per LeafSpy)

[Falcon73]

Last night was a scary experience. I've taken our 2018 Leaf SL down to --- on the dash before and only had ever lost a few grey power bars before.

However, last night the bars disappeared very rapidly after the first 3. I mean like a bar ever few seconds until it was down to 2 grey bars. We weren't able to keep up freeway speeds even though this all happened between 2 exits on the freeway.

We got off on Bake Parkway, crawling and then the vehicle started to shudder violently. Thankfully we we able to pull over the the side and then I switched it to Neutral.

LeafSpy still showed 9.6% SoC when this ordeal was over, with 3.0kWh still in the battery. It also showed 7 miles to 5% battery, so this was an utter shock.

Turtle mode wasn't even on for a minute before things started shutting down and hard.

This doesn't seem normal. The batter still shows 11/12 health bars at 78% SoH, but something seems wrong.

Any thoughts? I will be contacting Nissan, yet again.

Thanks!

 

[Learjet]

do you have any weak cells per Leafspy? what was the cell voltage difference?

 

[LeftieBiker]

I agree that it appears to be one or more weak cells. An EV battery is only as good as its weakest cell(s). What appears to have happened is that one or more of your car's cells had its voltage fall off a cliff when the pack got low, and the BMS first adjusted SOC to match the average voltage, and then shut the car down when the bad cell's voltage got too low.

 

[Carmichael]

Your first probl was attempting to maintain highway speeds when the battery was so nearly drained.

You can't expect 10% to last very long at speeds above 60 Miles Per Hour. Also what was the battery temperature at?

 

[Stanton]

All of these posts ask good questions. I would love to see a LeafSpy cell graph...but I suspect you have already charged the car.