Total battery rebuild! Almost done - but help needed - solved!

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A1exander

Member
Joined
Jul 20, 2020
Messages
6
Location
Linköping, Sweden
Hi!
I saw a YouTube video of a guy in Ukraine who swapped all cells in his battery pack to lg chem NMC 60ah cells... This means approximately 40kwh of useable energy... So I got inspired and decided to do the same thing! I mean, how hard can it be...? I have a 2012/2013 Nissan Leaf (gen 1 battery pack).

First, I bought 200 cells (to have 8 spares), put them into packs of 2 cells, constructed aluminum connectors between the cells, put cables to all individual packs for balancing and... then I removed my pack and opened it. I measured the voltage to all cells to make sure I marked all balancing cables the right way, to make sure I connected them all correctly eventually... then I put all cells into the battery pack, re-connected all temperature sensors, heaters... and today, finally, I put the pack back into the car. Leafspy showed a nice balanced pack - the balancing cables must have been connected correctly (despite how ugly my wiring looks)! But now, here comes the problem. The car did not start, and the battery didn’t want to charge. Eventually I checked error codes and after clearing the codes, four remained. And this is where I need help. My guess is that P32E1 (HV system interlock error) is the code that causes me troubles. I also see this information in Leafspy that I don’t understand. Have I, after all, done something wrong when it comes to wiring? Shouldn’t be the case with LeafSpy showing all cell voltages, though... too high resistance somewhere?
No voltage on the main battery connector on the outside of the battery.

Any thoughts?

Thank you so much in advance! I will post pictures when I figure out how to...

Best regards,
Alexander from Linköping, Sweden
 
That might actually be the cause... I went through the pictures I took, and it looks like a black connector with 2-wires that is connected on the bottom of the holder for the service plug, (and on google on later models the connection seems to be just outside of the holder instead) and I don’t remember neither unplugging or plugging that cable, but I can see a cable on that position in my pictures... I will try to drop the battery tonight and have a look at it. Thank you in advance!
 
How much were the cells, by the way? This sounds very similar to what EV Battery Rebuilds in Spain did, but they indicated it was not very economical.
 
It worked! Thank you! I had forgotten that cable...! I am now charging the car, and have also went for a short ride in it and so far so good. No error codes. I will go for a longer ride tomorrow to see how it all works.

I paid, all in all, about 5000 USD. And then I have all my original cells left, to do whatever I want with them... It was however pretty time consuming. Of course I have never done this before, but all in all I probably put around 100 hours into this project... If I were to do it again I might be able to do it in about half that time, but that is still a lot of time.
 
A1exander said:
It worked! Thank you! I had forgotten that cable...! I am now charging the car, and have also went for a short ride in it and so far so good. No error codes. I will go for a longer ride tomorrow to see how it all works.

I paid, all in all, about 5000 USD. And then I have all my original cells left, to do whatever I want with them... It was however pretty time consuming. Of course I have never done this before, but all in all I probably put around 100 hours into this project... If I were to do it again I might be able to do it in about half that time, but that is still a lot of time.

Congrats!
 
Thank you! It’s been working pretty well, and I am over all very happy with the outcome, but the cells aren’t perfectly balanced (about 70mv off at the moment). I hope they will balance over time, otherwise I will change affected cells eventually or something similar, since I have 8 spares. I have now driven about 300km (approx. 200 miles) so far without any issues.

I bought the cells from alibaba.com, so China, but imported from South Korea (cells are supposed to be 60 AH LG NMC cells, and seem legit). Only problem with the NMC chemistry is that a large amount of the energy is stored at a lower voltage than the original cells (LMO chemistry, right?), which means about half of the energy is left when the car says it is out of juice. So the “guess-o-meter” is pretty off, but in the right direction anyway.
 
How is the cell balancing going ? Have you had problems with it hitting turtle mode when under load ?
 
The balancing is slightly off, still one “module” (pair of cells) that is about 50mv off when fully charged. That means I can’t charge the last 5-7% or so of the rest of the battery pack... so I might end up changing that pair some time.

Nope. Never hit turtle mode so far, even during full load after 200km driving. But I can’t really use the guess-o-meter at all. When it says the battery is dead, I have more than half left. So far, the longest I have driven has been slightly over 200km, and I would guess I had at least 20% capacity left. But I would say I’m pretty satisfied with approximately 200-250km range with normal driving. I’ve used the car for a bit more than 3000km after the battery rebuild with no issues so far. :)
 
Did you take any pictures / English language notes for this? I am looking at doing the same for my 2012, 8-bars 24 kWh Leaf. I'm looking at $3000 in 51 Ah battery pouches from Alibaba, I calculate 36 kWh final product. I've seen the Ukraine video:

https://www.youtube.com/watch?v=BHu0Og0FWoc

I'm guessing you bought these?

https://www.alibaba.com/product-detail/Rechargeable-3-7V-60Ah-Polymer-Lipo_62387465456.html

(Or similar, 300x100x14.5mm)

I was considering:

https://www.alibaba.com/product-detail/JEVE-Pouch-Cell-NMC-3-7v_62533615485.html

(306*102*11.4mm)

And having some detailed instructions might help me figure out if that might still be able to fit.
 
https://www.youtube.com/watch?v=4K7Qta1YGyc
For English speaking folks:
62kWh usable
70kWh takes from 0 to 100% from a grid
weight +120 kilos to stock 24kwh pack
pack is lowered from stock mounts on 1cm(3/8 inch) with top lid modifications
He starts his trip at 4:45am at 17c outside and battery temp at 25c
Car was been driven on highway(arrival to chademo station at 9:52am) and ambient temp is 24c 341km with 7.2km/kWh temp of the pack at this moment 26c soc 34% with avarage cell voltage 3.55v
After 31min on chademo station current almost didn't dropped: 108.7A from max 115A from station, 63% soc, 20.4kWh consumed from charging station.
At the and of the charging session battery temp as been 38c, soc77.7% from leafspy, and average cell voltage at 4.08v. 44kWh was been consumed from station and charging session was been 1 hour 31min. Current at the end of this session was been 17A.
After 733km he is arrived at the distination(hotel). avarage is 7.8 km/kWh, battery temp is 37c, outside temp 31c, soc 43.6, 3.51v avarage voltage.
Car was been left on L2 charger. after 11 hours car have a chance to consume 60kWh. At the time of disconnection, car was been consuming 4A(220v) After night at the hotel.
Then Dmitry start going back home. After first 300km he got average 10.6 km/kWh with battery temp 28c and soc 67.7% and cell voltage at 3.73v.
At 457km mark he got 10.8 km/kWh.
At 500km he got 48.6% soc, outside temp 32c, battery temp 32c at 3.55v cell voltage.
At 600km mark with 10.9 km/kWh 3.48v cell voltage.
At 630km he got charge soon light.
At 650km mark Dmitry disided to stop. Cell voltage is 3.2v. He decided to call his buddy to get towed on the tow strap to his house.
Autor don't sharing what kind of cells was been used and what kind of LBC was been used as well.
But as far as i know, its LBC what was been build from scratches in Ukraine.
 
Montsamu - I did take a lot of pictures, I just don’t know how to post them here...

Yes, the size of the cells were 300x100x14.5mm. I connected them with aluminum tabs that I made myself. It’s a pretty big project, but I think it was worth it in the end... :) As a total I used 192 cells, but naturally in 96s2p configuration. One of the cells eventually went bad, so I had to open up the pack and change it, but after that it’s been working fine.

Pashko90 - Awesome project!
 
Hey A1exander, how is your upgrade going?
I did exactly the same as you to a 2014 leaf SOH 10 bars, not getting near 200kms per charge
 
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