DC Fast Charging messing with gauges

A couple of days ago I got to use the new (and currently only) DC fast charger in Dallas. Using it was pretty simple. I pulled near the charger with 3 bars left. When connected, the charger indicated a 41% SOC remaining in the battery (which makes sense when you add the hidden ~15-20% after the bars are gone). The charger charged the car to 91% and did an auto shutoff just like it should.

The gauge problem occured when I got back into the car. At a 91% SOC I was expecting maybe 2 bars depleted at most (maybe one if lucky), but the car showed a full 3 bars depleted, which I seriously doubt was correct, the top 3 bars shoudn't hold 9% total charge. Secondly the "charge time" on the small display in the center showed both times as zero (for 120 and 240), which we know is completely wrong with a 91% SOC AND three (supposed) bars depleted.

Cycling through the different menus did not result in a different reading for the bars or the estimated time to recharge. Turning the car on and off again did nothing as well. I decided to then just take my drive home and hopefully something will work out. After driving for a bit, I noticed I hadn't depleted a bar yet, odd seeming how long I had already driven, but I didn't think anything of it. Then I got onto the tollway bring myself up to highway speeds (65 here) and still nothing. I was starting to think the gauge had been broken so I started flooring it, pushing the car up to 80+ and accelerating and passing people like a bat out of hell, knowing this would probably show some effect soon. It took me 15 minutes of driving aggressively to finally get a bar to drop off the range. This would now total about 30 minutes of total driving, which should have had an effect a long time ago. Once I lost the bar, the charging times popped back on, showing the correct charging times (2 hours 240 and I can't remember the 120).

So why did the car think it was full when estimating the charging times, I had full regen, so it obviously knew the battery was not at 100% SOC. And why did the "fuel gauge" show as it did. From the experience there was at least one additional bar above that was not displayed (no way I could have driven as a I did and only burn one bar). Has anyone else experience this quirk after a DC charge?

Pipcecil said:

When connected, the charger indicated a 41% SOC remaining in the battery (which makes sense when you add the hidden ~15-20% after the bars are gone). The charger charged the car to 91% and did an auto shutoff just like it should.

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The problem is that per the service manual, if you start DC Quick Charging below 50% SOC, the Nissan LEAF will automatically stop charging at 80% SOC, not 90%. If you start DC Quick Charging above 50% SOC, the Nissan LEAF will charge to 100% SOC.

Three bars down should be about right for 80% SOC.

I thought that to be the case, but the charger stated it at 91% charge (although it could be wrong), which I assumed (although maybe incorrectly) was correct since the original SOC was correct when it connected (why one would be off and the other wouldn't is strange).

Regardless, this still doesn't account for the gauges on the car registering as "full" and showing no 0:00 to recharge and only displaying the correct amount when a bar was used from the fuel gauge. The recharge time should have still showed something since the car was not fully charged. Something is not right. I think next time I am going to charge to 100% and see if the fuel gauge shows full bars and again at 80% to see if the problem is replicated.

Pipcecil said:

the charger indicated a 41% SOC remaining in the battery..... The charger charged the car to 91% and did an auto shutoff just like it should.

The gauge problem occured when I got back into the car. At a 91% SOC I was expecting maybe 2 bars depleted at most (maybe one if lucky), but the car showed a full 3 bars depleted, which I seriously doubt was correct, the top 3 bars shoudn't hold 9% total charge.

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Our SOC meters show three bars at 31%-36%. It's also possible that there was 41% in the battery, if you had shut off the car with 4 bars, and then turned it on to now show 3 bars.

Or, the charger is measuring something different than we are, like total battery voltage.

Given that the charger showed 91%, but you vehicle fuel gauge showed 80-ish %, I'm guessing the charger reads about 10% too high.

Pipcecil said:

I thought that to be the case, but the charger stated it at 91% charge (although it could be wrong), which I assumed (although maybe incorrectly) was correct since the original SOC was correct when it connected (why one would be off and the other wouldn't is strange).

Regardless, this still doesn't account for the gauges on the car registering as "full" and showing no 0:00 to recharge and only displaying the correct amount when a bar was used from the fuel gauge. The recharge time should have still showed something since the car was not fully charged. Something is not right. I think next time I am going to charge to 100% and see if the fuel gauge shows full bars and again at 80% to see if the problem is replicated.

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A 100% charge is a good idea.

Do you have your timers setup for 80% charge? If so then DC charge to 80% would leave the time to charge showing as zero, since you're already at 80%. That doesn't explain why you showed 3 bars down and it took a while to loose the next one. My LEAF shows 2 bars down when charged to 80%.

Seems like after the one QC I did, the car showed 9 bars of charge as well. I didn't notice or else don't remember any of the other issues mentioned.

Maybe consider getting garygid's SOC doo-hicky.
Then you can have a better source of accuracy.
.

I just had the same experience as pipcecil at the same charging station (not that it should matter). I started at a higher level, but the gauges on the Leaf did not budge after 15 minutes of DC charge. I drove about 10 miles (8 at 65+ mph) to my house and the gauges had still not budged (reading 70% and 70 miles all the while). As an experiment, I plugged in the level II charger. After 20 minutes, it had apparently added 20 miles of drive range and taken my car to about 90% charge, an unlikely rate for level II. Clearly there's an issue with the Leaf's reporting of battery state with Level III charging. Hopefully, this isn't a safety or "wear and tear" issue.

As an aside, I am starting off by reporting this to my dealership, but if someone has a phone number at Nissan for a group that might want to hear this, please pass it on.

Did you check the temperature gauge of the battery after the QC? Per the service manual it says that at higher temperatures each SOC bar represents more charge (and at lower temperatures less charge), so for the same charge a higher pack temperature would show less SOC bars but each bar would represent more charge. This could explain why the 9 bar took so long to deplet.

Good thought. Temp was in the middle of the gauge, though, both when I parked at the level 3 charger and at my home station.

I doubt that temperature would account for that much of a difference. We are talking incremental changes in capacity with temperature change, not the very dramatic results he observed...

vegastar said:

Did you check the temperature gauge of the battery after the QC? Per the service manual it says that at higher temperatures each SOC bar represents more charge (and at lower temperatures less charge), so for the same charge a higher pack temperature would show less SOC bars but each bar would represent more charge. This could explain why the 9 bar took so long to deplet.

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