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Packaging for second life lithium 18650 battery cells

OffgridSystems

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Dec 3, 2023
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South Whidbey Island - USA
I'm working on packaging and BMS solutions for cylindrical cells, of all lithium types. Current product on eBay has 18650 (working on 2170) cell packaging with and without JK active balancing BMS. All packages are bring-your-own cells. System uses high current gold plated Beryllium Copper springs instead of welding, so no-weld and no soldering. Also uses flat cable for cell sense wires instead of fragile single conductors. Specs and build information is available for both 12 and 24V nominal system, or you can roll your own and make any voltage you can imagine.

Thanks for viewing, appreciate any feedback!
Tim

12V with BMS:

12V without BMS:
handheld 12V system with BMS.jpg
12V/24V without BMS

Build your own boards using DK springs?
 
I'm working on packaging and BMS solutions for cylindrical cells, of all lithium types. Current product on eBay has 18650 (working on 2170) cell packaging with and without JK active balancing BMS. All packages are bring-your-own cells. System uses high current gold plated Beryllium Copper springs instead of welding, so no-weld and no soldering. Also uses flat cable for cell sense wires instead of fragile single conductors. Specs and build information is available for both 12 and 24V nominal system, or you can roll your own and make any voltage you can imagine.

Thanks for viewing, appreciate any feedback!
Tim

12V with BMS:

12V without BMS:
View attachment 190002
12V/24V without BMS

Build your own boards using DK springs?
Nice! Cell(s) will go bad one day, you make the rebuild or repair much easier.
 
Thanks JMack! I'm working on 2170 cell type next, but I'd like to package larger cells too. If you know of any larger cells, I'd love to hear how you would package them, in what parallel grouping would you do? I'd look at the 4680 type but I don't think there will be a lot of salvage cells coming out of that structural pack.
A lot of lithium iron phosphate (LFP) cells come in the 32650 or 32700 cylindrical sizes...maybe that would be a good one to do?

Thanks again!
Tim
 
Thanks JMack! I'm working on 2170 cell type next, but I'd like to package larger cells too. If you know of any larger cells, I'd love to hear how you would package them, in what parallel grouping would you do? I'd look at the 4680 type but I don't think there will be a lot of salvage cells coming out of that structural pack.
A lot of lithium iron phosphate (LFP) cells come in the 32650 or 32700 cylindrical sizes...maybe that would be a good one to do?

Thanks again!
Tim
I had no ideal of all the form factors for cylindrical cells 18650, 26650 and a few 2170’s is all I ever worked with. Thanks for the eBay link. Last week I stepped into the prismatic cell world purchasing 7.5 kWh in 3 Sonnen brand server rack batteries. I started with Lead Acid to 18650 to 26500 so it was time to go prismatic. I won’t stop with the cylindrical cells there are too many free ones to pass up. I cleaned out a failed computer business two weeks ago and got over 500 free cells none less than 2900 mAh. When you savage cells like I do. No matter how much capacity and ir testing you do It is a gamble. I have spot welded 16s20p (26650’s) all that my arms can carry on a good day, only to see fail a short time later so I find the bad cell(s) and go through hacking nickel strip and break the cell holders hoping to press the bad cell(s) out. But the cell sleeve is mangled and makes it a bear to slide out. looks Like the one cell I can see is sleeveless, is that true? Also 48v nominal inverters are king.
 

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