Second Life Nissan Leaf Cells - Battery Pack Assembly

[HighTechLab]

Good morning everyone!

Super excited with the chance to get my hands on some second-life Leaf cells. I am actually working with BigBattery.com as well (The same company that sent Will the Nissan Leaf battery pack) however mine came as kit that I assembled so as to better get my hands on the internals.

I have a few plans for this battery pack, thinking of making a mini Off-Grid box that can be used on a friend's fishing boat to run a bunch of LED Flood lights for bow fishing at night, however another thought is to make it all removable so that it can also be used on its own when he goes camping with his trailer to keep him from having to run his generator as much.

Check out the video I made and let me know what you guys think of this and any concerns that I should cover in the part-2 video.

 

[Picasso]

I have worked a ton with nissan cells. Moving forward with them I want to keep them pack intact on a sunnyboy storage. Getting unmatched cells is a big problem with the leafs cells. cell lab 8 or other high dc-dc charger is a must if you want to do thing fast matching stacks. The gen 2's also have two different chemistries. Note also USA and Japan made cells. You can tell them apart a bit from the printing on the cell.

 

[HighTechLab]

It appeared to me that all these cells were matching, you can see when I did the voltage testing in the video that they matched up pretty well at 7.55v per cell.

 

[Dreen]

I have worked a ton with nissan cells. Moving forward with them I want to keep them pack intact on a sunnyboy storage. Getting unmatched cells is a big problem with the leafs cells. cell lab 8 or other high dc-dc charger is a must if you want to do thing fast matching stacks. The gen 2's also have two different chemistries. Note also USA and Japan made cells. You can tell them apart a bit from the printing on the cell.

So do the US cells match with US and Japanese with Japanese? Or is it just a crap shoot?

 

[Picasso]

around 2013 was the first US built leafs, you can see minor differences. Cell interconnects metal thinner on US packs. Id take a Japan pack over a USA pack. Also is now UK made leaf cells. and 3 chemistry changes. Leaf cells do best with 4+ parallel. When getting cells that you havnt taken out of the pack yourself TEST TEST TEST. I played a good amount in little 4s1p bricks from my own cells I took out of leafs and also those ordered from techdirectclub.com The ones from techdirectclub.com had 60%-80% capacity and are a mix from many packs. Same pack cells all wear evenly from what Ive seen taking apart 3+ leafs. He has to be getting warranty returns direct from Nissan. Unless buying full packs knowing you got matched cells I would avoid.

 

[HighTechLab]

around 2013 was the first US built leafs, you can see minor differences. Cell interconnects metal thinner on US packs. Id take a Japan pack over a USA pack. Also is now UK made leaf cells. and 3 chemistry changes. Leaf cells do best with 4+ parallel. When getting cells that you havnt taken out of the pack yourself TEST TEST TEST. I played a good amount in little 4s1p bricks from my own cells I took out of leafs and also those ordered from techdirectclub.com The ones from techdirectclub.com had 60%-80% capacity and are a mix from many packs. Same pack cells all wear evenly from what Ive seen taking apart 3+ leafs. He has to be getting warranty returns direct from Nissan. Unless buying full packs knowing you got matched cells I would avoid.

I have a nice Fluke 287 logging meter on the way (Arrives tomorrow!!) that i'm going to be using to check the capacity on these cells and see how they compare.

 

[HighTechLab]

I love my new fluke meter - Based on a rudimentary test that I ran, using a water heating element in a 5 gallon bucket, I estimate my pack gave 2.0 to 2.2 KWH. Now, this was a really basic test at a very heavy draw, for my actual capacity test I'm going to run a much lower C rate, but yeah should be excited to get a good plot on the voltage discharge curve of this pack!

 

[sphoover]

Great video! Quick question for you. As I just picked up two of these without the shell, or display.

1) How do you know the BMS is functioning?
2) Both of mine only came with andersen female/male output connections. Can I connect both 48V packs together via the andersen's on each, and then wire the 48V parallel negative off 1 end of the first pack, and positive off the other end of the second pack connecting to my charge controller? Or do I need to buy andersen parallel cables to connect both packs, and then a common out pos/neg to my charge controller? Thanks.

- Shawn

 

[Picasso]

I love my new fluke meter - Based on a rudimentary test that I ran, using a water heating element in a 5 gallon bucket, I estimate my pack gave 2.0 to 2.2 KWH.

much higher vs I would have guessed. New each cell module should be around 60Ah.

These are good bang for the buck and work up to 60v in my testing, good match for those leaf packs. https://www.renvu.com/Solar/Solar-Clearance/Sparks-Power-Alpha-Series-120W-LED-Light-External-Driver

 

[welnat]

Have you done the full load test at lower discharge rate?

 

[TDLanders]

It's been 3 years of usage on my G1 nissan battery bank. I went from 6v cart batteries and have not looked back. I dont run a BMS system but I do charge and discharge slowly for a bank this size. I do my weekly checks and they are extremely consistent.

 

[HighTechLab]

I did do the capacity test, although it took me quite a while to finally get the video out.

 

[welnat]

This was really well done and good, thank you!

 

[Calvin]

I have some of these Nissan Leaf batteries (8p14s)in my solar system (48v) and would like to know what’s the charge and discharge voltage recommended.

at the moment I charge them to 58v and my cut off voltage is 48v. What’s your recommendation?

 

[Ampster]

at the moment I charge them to 58v and my cut off voltage is 48v. What’s your recommendation?

Mine is getting ragged and is only 12S so I charge the cells to 4.05 and don't go below 3.5 volts per cell. For your pack that would be 56.7 and 49.0

 

[Calvin]

Mine is getting ragged and is only 12S so I charge the cells to 4.05 and don't go below 3.5 volts per cell. For your pack that would be 56.7 and 49.0

Thank you Ampster. Could you give me a bit more details on why these settings?

 

[Ampster]

Thank you Ampster. Could you give me a bit more details on why these settings?

As I mentioned, my pack is ragged. I call it a Frankenpack because it has at least 3 vintages of modules. I never capacity matched it and at higher voltages of charging or discharging the deltas between the high and low voltage cells starts to increase dramatically. YMMV.
Also, Initially the pack was just for backup and tended to stay at the top. I wanted to use a lower cell voltage to presumably extend or preserve the life of the pack.

 

[Silentpower]

Yikes ?
I have NMC cells 5p14s and have taken them down to below 46v... I'm slightly worried now!
EIG recommended 3.3vpc so I thought I wasn't ragging them excessively, I might have a rethink lol. I charge to 56.5v

 

[Calvin]

As I mentioned, my pack is ragged. I call it a Frankenpack because it has at least 3 vintages of modules. I never capacity matched it and at higher voltages of charging or discharging the deltas between the high and low voltage cells starts to increase dramatically. YMMV.
Also, Initially the pack was just for backup and tended to stay at the top. I wanted to use a lower cell voltage to presumably extend or preserve the life of the pack.

I see what you’re saying because I have noticed the cells voltage drifted when charged to high voltage and when discharged low. Thanks for the info

 

[Calvin]

Yikes ?
I have NMC cells 5p14s and have taken them down to below 46v... I'm slightly worried now!
EIG recommended 3.3vpc so I thought I wasn't ragging them excessively, I might have a rethink lol. I charge to 56.5v

Do you use a BMS?