kevmk81
Posts: 29
Joined: Wed Mar 30, 2016 6:46 am
Delivery Date: 30 Mar 2016

Battery charging beyond 100% after strange activity earlier in the day

Thu Oct 18, 2018 6:11 pm

This morning as I pulled into my work's parking lot I had around 29% charge. I pulled in, put the car in park and turned the car off. After I turned it off there was an odd noise - almost sounded like someone trying to start their car but the battery wouldn't turn over, that type of noise. So after I heard the odd noise, I turned the car back on only to see that 29% charge suddenly dropped down to 24%. Fast forward to when I get home. I typically charge to 80%, but this time I wanted to charge to 100% just out of curiosity of what would happen. I come back later - well beyond the time that it should have taken to fully charge the vehicle - and I see that 1) there's a good amount of warmth coming from the front of the car and 2) that the 3rd blue light is still blinking. I unplug the charger, turn on the car and it's at 100% charge!? So not sure what's up with that. I leave the house to take the car for a spin to see if there'd be regen braking - and it regens to all of the "circles" except for the last one - if that makes sense. So even though it was fully charged - it was regenerating power... :-/ I drove it around long enough to drop the charge down to 73% - turned the 80% charge back on when I got home - charged it - and it stopped when it hit 80%. I'm not sure I even want to charge to 100% now - I feel like something is wrong. Anyone else run into this issue?? Last thing I need is a car that's on fire in my garage.

kevmk81
Posts: 29
Joined: Wed Mar 30, 2016 6:46 am
Delivery Date: 30 Mar 2016

Re: Battery charging beyond 100% after strange activity earlier in the day

Thu Oct 18, 2018 6:33 pm

I have 240v charging at home by the way. Clippercreek HCS-50

WetEV
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Re: Battery charging beyond 100% after strange activity earlier in the day

Thu Oct 18, 2018 10:07 pm

kevmk81 wrote:I turned the car back on only to see that 29% charge suddenly dropped down to 24%.


This isn't that unusual... BMS estimates SOC two different ways. By open circuit voltage when the battery is disconnected, and by a much more complex and less accurate method while driving.
WetEV
#49
Most everything around here is wet during the rainy season. And the rainy season is long.
2012 Leaf SL Red (Totaled)
2014 Leaf SL Red

cwerdna
Posts: 8282
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Location: SF Bay Area, CA

Re: Battery charging beyond 100% after strange activity earlier in the day

Thu Oct 18, 2018 11:05 pm

You didn't charge beyond 100%. Nissan doesn't let you access part of the battery at the top and bottom. 100% on the dash display isn't actually 100%. It's a bit less.

From your previous posts, it sounds like you have a '13, like me.
kevmk81 wrote:I turned the car back on only to see that 29% charge suddenly dropped down to 24%. Fast forward to when I get home. I typically charge to 80%,

Agreed with what WetEV said. Also, if you are usually not charging to full, that might help exacerbate inaccuracy.

kevmk81 wrote: but this time I wanted to charge to 100% just out of curiosity of what would happen. I come back later - well beyond the time that it should have taken to fully charge the vehicle - and I see that 1) there's a good amount of warmth coming from the front of the car and

Normal. This happens even if you don't charge to 100%. The on-board charger heats up and so does the inlet. Next time, charge for at least an hour and open the hood while charging. You'll feel the entire PDM stack is warm.

kevmk81 wrote:2) that the 3rd blue light is still blinking. I unplug the charger, turn on the car and it's at 100% charge!?

As for the bolded part, when the battery is closer to full (usually somewhere past 92% (I don't recall the exact numbers) on the dash display), the car will begin ramping down charge power and then do 3 bounces at the end. Not much energy makes it into the battery during that phase. It's not linear or steady state near the top, unlike when you charge to 80% where it's basically the same power level the whole time (w/a bit of variance) then car abruptly cuts power draw to 0. See viewtopic.php?p=490435#p490435. Your previous posts mention you have Leaf Spy. You can see how many battery gids it goes up to. And, you can see the charging power. You'll see it go down just like my ChargePoint graph.

As I've posted many times, if the dash display is at 98% or so, often, when you unplug, it'll "jump" to 100%, even though a bit more juice can be added to the battery.
viewtopic.php?p=423754#p423754
viewtopic.php?p=339977#p339977
viewtopic.php?p=446914#p446914

kevmk81 wrote:So not sure what's up with that. I leave the house to take the car for a spin to see if there'd be regen braking - and it regens to all of the "circles" except for the last one - if that makes sense. S

Not abnormal at all. If you charge to 100%, you'll have 0 available regen circles until you deplete the battery for a bit. At what SoC % on the dash you'll have all regen circles available varies, and can vary depending on battery temperature, condition and how full the battery was to start with. I suspect they just want to make sure there's no module that goes beyond some set critical high voltage and that's the limiting factor. For heavily degraded '11s and '12s, I hear there's very little regen. See examples below:
viewtopic.php?f=27&t=21961&p=462072&hilit=regen#p462072
viewtopic.php?f=31&t=20275&p=432849&hilit=regen#p432849
viewtopic.php?f=31&t=13371&p=459925&hilit=regen+kw#p459925
viewtopic.php?p=447931#p447931

You will NOT have a fire. '11 and '12 Leafs only could be charged to 80% via the timers. On model year US '14+ Leafs, they REMOVED the charge to 80% option. You have no choice but to charge to 100% or to terminate it early via either means (e.g. timer, unplugging early, EVSE with its own timer or that can be scheduled/remotely controlled). We have at least a dozen '14+ Leafs at my work who charge there. They go to full. I suspect many other pre-'14s are charged to full, as well.

'13 Leaf SV w/premium package (owned)
'13 Leaf SV w/QC + LED & premium packages (lease over, car returned)
'06 Prius

Please don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

baustin
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Re: Battery charging beyond 100% after strange activity earlier in the day

Fri Oct 19, 2018 4:02 am

When you do a charge to 100% is when the BMS balances the cells in the battery pack. This can take some time, depending on how often it is done. It does not charge the battery beyond 100%, but it extends the length of the charge cycle. You should do a 100% charge, at least once a month, and let it run until it finishes and shuts itself off.
2013 Leaf SV - Cayenne Red - QC Port - LED Headlights

kevmk81
Posts: 29
Joined: Wed Mar 30, 2016 6:46 am
Delivery Date: 30 Mar 2016

Re: Battery charging beyond 100% after strange activity earlier in the day

Fri Oct 19, 2018 6:51 am

Makes sense - thanks for the replies. Yes mine is a '13 SV

One thing I forgot to add - after the car made its' odd noises yesterday morning - the dash reset (as it has done so a few other times in the past) - so efficiency was reset - the car on and car off noises came back on - etc...

How often do other peoples leafs reset?

WetEV
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Location: Near Seattle, WA

Re: Battery charging beyond 100% after strange activity earlier in the day

Fri Oct 19, 2018 7:44 am

kevmk81 wrote:Makes sense - thanks for the replies. Yes mine is a '13 SV

One thing I forgot to add - after the car made its' odd noises yesterday morning - the dash reset (as it has done so a few other times in the past) - so efficiency was reset - the car on and car off noises came back on - etc...

How often do other peoples leafs reset?


Checked your 12V battery recently?

LEAFs doing odd things often mean a weak 12V battery.
WetEV
#49
Most everything around here is wet during the rainy season. And the rainy season is long.
2012 Leaf SL Red (Totaled)
2014 Leaf SL Red

DaveinOlyWA
Posts: 13276
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Leaf Number: 314199
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Contact: Website

Re: Battery charging beyond 100% after strange activity earlier in the day

Fri Oct 19, 2018 8:12 am

kevmk81 wrote:This morning as I pulled into my work's parking lot I had around 29% charge. I pulled in, put the car in park and turned the car off. After I turned it off there was an odd noise - almost sounded like someone trying to start their car but the battery wouldn't turn over, that type of noise. So after I heard the odd noise, I turned the car back on only to see that 29% charge suddenly dropped down to 24%. Fast forward to when I get home. I typically charge to 80%, but this time I wanted to charge to 100% just out of curiosity of what would happen. I come back later - well beyond the time that it should have taken to fully charge the vehicle - and I see that 1) there's a good amount of warmth coming from the front of the car and 2) that the 3rd blue light is still blinking. I unplug the charger, turn on the car and it's at 100% charge!? So not sure what's up with that. I leave the house to take the car for a spin to see if there'd be regen braking - and it regens to all of the "circles" except for the last one - if that makes sense. So even though it was fully charged - it was regenerating power... :-/ I drove it around long enough to drop the charge down to 73% - turned the 80% charge back on when I got home - charged it - and it stopped when it hit 80%. I'm not sure I even want to charge to 100% now - I feel like something is wrong. Anyone else run into this issue?? Last thing I need is a car that's on fire in my garage.



Don't see really anything out of place here. You weren't by chance running LEAF Spy at the time?? Ahh... of course you wouldn't cause if you had, you wouldn't be posting this.

That clicking noise might indicate a boost of the 12 volt battery is in order. As the weather gets colder, edge case batteries start to fail. I would put it on a charger overnight at your earliest convenience.

You stopped the charge when it was in the balancing phase. This can last 2 hours but is not needed unless your trip will challenge the full range of the car. The other day (2018 with SOC meter) my LEAF was at 98% but LEAF Spy told me my charge was done. A "full" charge only goes to a real SOC of 97-98% on new battery.

I unplugged, rebooted and SOC meter immediately went to 100% although LEAF Spy verified no additional charge was added. In case you are curious, LEAF Spy registered a charging speed of .3 KW

Based on your observation that all regen was available but one circle suggests you were early in the balancing stage. It is the BMS desire to "top off" during the balancing stage that is a likely huge contributor to degradation. I would avoid it as much as conveniently possible.
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 11,987 miles, 485 GIDs, 37.6 kwh 110.89 Ahr , SOH 96.00, Hx 115.22
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kevmk81
Posts: 29
Joined: Wed Mar 30, 2016 6:46 am
Delivery Date: 30 Mar 2016

Re: Battery charging beyond 100% after strange activity earlier in the day

Fri Oct 19, 2018 9:00 am

Yep, 12 v is fully charged actually (have dealt with 12 v battery issues in the past and I've figured out what works for me)! I haven't used leaf spy lately tbh... i might start using that again

goldbrick
Posts: 252
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Re: Battery charging beyond 100% after strange activity earlier in the day

Fri Oct 19, 2018 9:50 am

DaveinOlyWA wrote: It is the BMS desire to "top off" during the balancing stage that is a likely huge contributor to degradation. I would avoid it as much as conveniently possible.


This is the first time I've heard this. Can you elaborate a bit?

And how important is it to 'balance' the cells. If LeafSpy doesn't show a huge imbalance is there anything to be gained by letting the charger go until it stops? I rarely or never need more than about 40% of my full range in any single day so I could go indfefinately without a full charge. I haven't charged to full since the the cooler weather of the Spring and I'm wondering now if I need to do it at all...

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