Charging SPEEDS UP after 80%!!!!!!

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Hyscore

New member
Joined
Apr 9, 2016
Messages
3
I have only had my 2013 Leaf for 3 days but I seem to have encountered a charging anomaly that I have been unable to find in any of the other posts on this board... so by definition I guess it is unlikely that anyone is going to be able to help me, but here goes....

I am using a L2 charge point and the Leaf has a 6.6 Kw charger.

Everything I have read tells me that charging should slow down on that final push from 80% to 100%.

But that is not what is happening in this case. It seems to take the predicted time to charge to around 80%, but then it charges absurdly fast up to 100%.

The car has done about 15500 miles, and I suspect it may have been with the dealer doing very little mileage for a couple of months until it came to me.

Has anyone else experienced this anomaly, and is it an indication that all is not right with my battery?
 
Hyscore said:
I am using a L2 charge point and the Leaf has a 6.6 Kw charger.

Everything I have read tells me that charging should slow down on that final push from 80% to 100%.

But that is not what is happening in this case. It seems to take the predicted time to charge to around 80%, but then it charges absurdly fast up to 100%.
...
Has anyone else experienced this anomaly, and is it an indication that all is not right with my battery?
Re: the bolded part, they're most likely referring to DC fast charging (via CHAdeMO), NOT L1 or L2 charging (via 100 to 240 volts AC). Actually, the slow down of charge from max rate starts well before 80% on CHAdeMO. Even at 80%, it may not actually be that slow.

It most certainly does NOT slow down at all at 80% on a 30 amp L2 EVSE at 208 volts. It only slows down somewhere past ~95% as indicated on the car's dash display. Also see graph at http://www.mynissanleaf.com/viewtopic.php?p=338038#p338038.

More recently, I did get Leaf Spy and if I wait until the battery is nearly full and can also observe the slow down on level 2 on the charge graph screen. Threre 2 numbers there. It's supposed to be the power in kW going into the pack and the second is the power in kW the charger's reporting. On the free L2 EVSEs I use (which might only be 208 volts), it'll slow down from say 5.x (5.7?) kW at full speed to somewhere below it, sometimes as low as 0.x to 1.x kW when nearly full.

BTW, if I only charge to 80%, then I resume charging (often remotely), L2 charging goes full power for at ~50 minutes or an hour or so before it goes into the ramp down phase (in the above graph) then the 2 or 3 bounces at the end.

I have pics of CHAdeMO charging (some are my former Leaf and some are of someone else's) w/values like these:
86%
Power: 9.504 kW
Energy (dispensed): 14.800 kWh
Elapsed time: 31:09

77%
Power: 20.988 kW
Energy: 6.900 kWh
Elapsed time: 13:11

90%
Power: 8.295 kW
Energy: 9.700 kWh
Elapsed time: 25:45

All of these are above L2 speeds.
 
Hyscore said:
I have only had my 2013 Leaf for 3 days but I seem to have encountered a charging anomaly that I have been unable to find in any of the other posts on this board... so by definition I guess it is unlikely that anyone is going to be able to help me, but here goes....

I am using a L2 charge point and the Leaf has a 6.6 Kw charger.

Everything I have read tells me that charging should slow down on that final push from 80% to 100%.

But that is not what is happening in this case. It seems to take the predicted time to charge to around 80%, but then it charges absurdly fast up to 100%.

The car has done about 15500 miles, and I suspect it may have been with the dealer doing very little mileage for a couple of months until it came to me.

Has anyone else experienced this anomaly, and is it an indication that all is not right with my battery?

Nothing wrong.

Another point to consider that wasn't mentioned by cwerdna is the dash SOC% lies slightly at the top end of the charge. It'll say 100% on the dash and 93% to 97% on leafspy depending on the temperature, health of the battery pack, and so on.

I don't know at what point internal and dash SOC% diverge but it's likely around where you saw the "speed up".

Grab a OBDII adapter and a smartphone and the free version of leafspy to see if that is the explanation. It will also tell you the actual power going to the battery pack so you can tell if the power changes or if it is just the SOC% difference that is confusing the issue.

Oh and I'm assuming you are looking at SOC% when you talk about the speed up, another place that it will seem to speed up is the dash estimate of charge time to 100%. That time is pessimistic and you'll always finish before the time estimate so if you watch the estimate, it changing near the end could make it look like a speed up as well.
 
Wow - Thanks for all the help! :)

I am suitably reassured that the effect I have observed is more likely to be some kind of calibration glitch rather than a sign that my battery is defective in any way.

I have ordered one of the transponder thingies that should let me use LeafSpy.

It is also in my mind to run the battery down to about 20% and then charge to 100% and leave the charger connected for a few hours afterwards. (This would be my attempt to balance/calibrate (?) the battery as described in several posts on here...

...but will I risk doing any harm by leaving the charger connected for this long after 100% on a 2013 Leaf?)

Thanks!
 
Hyscore said:
Wow - Thanks for all the help! :)

I am suitably reassured that the effect I have observed is more likely to be some kind of calibration glitch rather than a sign that my battery is defective in any way.

I have ordered one of the transponder thingies that should let me use LeafSpy.

It is also in my mind to run the battery down to about 20% and then charge to 100% and leave the charger connected for a few hours afterwards. (This would be my attempt to balance/calibrate (?) the battery as described in several posts on here...

...but will I risk doing any harm by leaving the charger connected for this long after 100% on a 2013 Leaf?)

Thanks!

You can leave the charger connected for hours at a time no problem, even a day or two.

Eventually that will drain the 12v so you wouldn't want to leave it plugged up for weeks at a time.

If you just want to balance the pack you can do that from any charge level to full, don't have to discharge it very low. It balances at the top of charge so any time sitting on the charger above 90% or so is going to start balancing activities.

If you want to test the low end you can but balancing the pack is the big issue for calibration. With leafspy active I have no reservations about driving down to 2 or 3 miles remaining but I've never driven to turtle and don't plan to do so just for testing.
 
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