Slow chademo charging, BMS problems?

My Leaf never had QC's by previous owner, yet i did 4 (thats total, according to LeafSpy) and Chademo seems slow. When the battery was below 20% SOC, the charge rate was 46amp's, when its over 50% SOC it drops down to 20-30amps and at 70% - 15amps.

I've charged at 3 different manufacturer chademo stations and all are the same. Any ideas? Battery health is 91%, hx 84%. Its 2012 model.

My charging time from 18% till 76% took 1hr32mins; other time 31%-82% - 1hr 5mins. In a timed station it managed to 52% to 75% in 30minutes.

Is there a way to reset BMS or something?

Wow, something doesn't sound right. While I'm not QC expert I have used it a few times at a local Nissan dealer and all 4?? times it was smoking fast, like 20% to 80% in something like 30 minutes. I've done both my '12(missing 2 bars) and '13(full bars) and both were similar. I've also done it in quite cold weather, like teens to single degrees and both times it still charged fast and I even gained a battery temp bar(good thing when it's it in the single digits).
Heck I get ~30%/hr charge rates with L2 on my '13, your not getting much faster than that with L3 :?
I really have no idea what it could be, maybe someone else who uses QCs more often might have insight.

I drove friends 2011 with qc a year before, that one also did very rapid QC's... yet mine doesnt for some unknown reason....

Kristis said:

My charging time from 18% till 76% took 1hr32mins; other time 31%-82% - 1hr 5mins. In a timed station it managed to 52% to 75% in 30minutes.

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What was the temperature when you did this QC? If it was -10C or below, that would likely be in the ballpark of what you can expect.

It was +5/8C

Yesterday i had two leaf drivers at same QC's, both of them had similar SOC yet finished way faster then i did...

Did you look at cell voltage display in Leaf Spy while charging? BMS (Nissan calls it lithium battery controller or LBC) will limit charging current to keep individual cell pairs from exceeding maximum allowable voltage. Therefore, an out-of-balance pack or a single weak module will slow down L3 charging. My 2011 had lower quick charge rates in low temperatures once its battery started to deteriorate.

Kristis said:

It was +5/8C

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Boom... there it is. You have to warm that pack up. Drive it or get heating pads under there that you can plug into 120 volts prior to your drive (you will have to remove the lower plastic panels to get the heating pads in there).

Don't use a heating pad that gets over 104F / 40C.

But battery pack usually has 4-5bars... Thats too low for it to function? Now it has improved a bit and im getting 3kw in 10mins

Kristis said:

But battery pack usually has 4-5bars... Thats too low for it to function? Now it has improved a bit and im getting 3kw in 10mins

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It is functioning, just not very fast... because it is cold.

Kristis said:

But battery pack usually has 4-5bars... Thats too low for it to function? Now it has improved a bit and im getting 3kw in 10mins

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It's normal to get 5kWh per 10 minutes from ChaDeMo. Maximum is 6kWh with 24kWh pack.
If the battery is at 4 bars charge rate will slow down sooner. And with 3 bars it is extremely slow (below +5C pack).

To get better charging speed discharge pack more - this will create more heat in the pack.
Also possible to drive aggressively. But you will also lose a lot of range due to that :lol:

But my 3kw is still lower then 5kw

Its +11c in here but theres no effect on charge speed. And chademo used to add 1 bar of heat to it, now it doesnt...

I Live in Vermont USA. This year we have had some cold. Some -10C. It mostly depends on the battery temp for how fast the QC works. The other factor mentioned are also possible. I find If I have 3 temp bars QC is about the same speed as L2 with my 6.6 kWh charger. Also the QC charger itself seems to be affected sometimes. Once the battery is up to 5 bars and the temps are above 5C I get 30-40-kWh out of a QC.

Sounds like it is a combination of cold and may be some of the previously mentioned factors. I would see how it does when the weather warms up. If it is still slow the you may have a battery issue.

Kristis said:

My Leaf never had QC's by previous owner, yet i did 4 (thats total, according to LeafSpy) and Chademo seems slow. When the battery was below 20% SOC, the charge rate was 46amp's, when its over 50% SOC it drops down to 20-30amps and at 70% - 15amps.

I've charged at 3 different manufacturer chademo stations and all are the same. Any ideas? Battery health is 91%, hx 84%. Its 2012 model.

My charging time from 18% till 76% took 1hr32mins; other time 31%-82% - 1hr 5mins. In a timed station it managed to 52% to 75% in 30minutes.

Is there a way to reset BMS or something?

Click to expand...

part of it is Nissan being way too conservative.

the other is likely temperature. cold means slower

and finally, part of it is Nissan BMS itself. It likely only checks and reports status to station one time. This means that your LEAF could start charging at lower curve rate due to cold cells but not speed up as the cells warm up. I have never seen the rate increase (kwh will go up as voltage of pack increases but amperage does not) no matter how much the temperature of the pack rises.

When this happens, you will see the amperage start to drop early, too early considering how much room your pack has.

get a 30 kwh LEAF. charging profile is MUCH better

As far as I've been monitoring, Leaf (at least 2014 version) always charges with one limitation in mind:
highest cellpair voltage. I've arrived to DC station with 3 temperature bars and charging is very slow.
But the highest cellpair voltage is still near the "designed maximum". Somewhere around 4.05-4.1V.
And in rare scenarios charging speed does increase. This happens due to warmer cell accepting charge
faster without going above voltage limit.