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They are great high output cells but obviously poor capacity. Depending on your needs and that price it’s a great price, but if you are looking for distance you may be a little disappointed. Probably better to say what your goal is for using them as all cells have good qualities.
 

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You can get more capacity at lower cost and not have to assemble the thousands of individual cells by using a salvaged automotive pack.
On the other hand, if you need power, no automotive pack comes close to the power capabilities of these cells.

They are good cells, we used them in the Genovation corvette that currently holds the world record for fastest street legal EV. But they are pretty old and there are better options these days. For example, the Samsung INR18650-30Q has the exact same internal resistance, but it is a 3Ah cell instead of 2.5Ah.

As many people are saying, if you are going to use them you need a good plan for hooking them together. If you don't plan to push extreme power out of your pack, there are a lot of easier and cheaper choices from salvage packs.
 

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Discussion Starter #6
Good thoughts.

This is for my 1994 Camaro conversion.

The Samsung INR18650-30Q does have high capacity but cost 0.80 more, at 2000 cells that's $1,600 for an extra 25 amps.

Yes I could search for a savage pack. Here are my thoughts on that:

Savage Pack:
Pros - Save ~$1-$2k
- Don't have to wire each cell
- Possible BMS/circuit protection

Cons - No idea if the pack is going to die in 1-2 years
- Have to fit a random package dimensions into the car

New 18650 Cells:
Pros - New cycles should last 6+years
- Can make the pack any shape/size desired
- Able to split the weight to balance the car
Cons - Expensive
- Have to wire each cell
- Have to create a BMS
 

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The only flaw in that plan is that the NMC 622 chemistry has proven to work with minimal temperature regulation, where as any time a cylindrical cell has been used it has required significant temperature management. and you will probably double the 200lbs of cells in coolant and heating requirements. I guess that would be an advantage to something like tesla modules that already have a well plumbed system with BMB boards that have already been hacked.
 

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On the other hand, if you need power, no automotive pack comes close to the power capabilities of these cells.
I thought about that too.

I'm using recycled 18650s from tool packs for my builds. 4000 cells is ~36kwh. And 640 horsepower.

For something the size of 4 milk crates and ~400lbs.
 

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On the other hand, if you need power, no automotive pack comes close to the power capabilities of these cells.
I thought about that too.

I'm using recycled 18650s from tool packs for my builds. 4000 cells is ~36kwh. And 640 horsepower.

For something the size of 4 milk crates and ~400lbs.
Hi Matt,
How reliable are these cells and how can I check their viability?
Also, where can I find 7000+ recycled 18650 cells?
Thanks,
Greg
 

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Discussion Starter #10
If a salavage pack is the way to go then what's everyone's opinon of the best pack to get?

I've heard Volt packs are good, but they are harder to come by then say a Prius pack.
 

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Hi Matt,
How reliable are these cells and how can I check their viability?
How do you want to measure reliability?

How can you check them? With a lithium-ion capacity checker.

If you pre-charge and post-charge and only use the capacity checker for discharge capacity testing, it takes about 4 hours per cell. Usually devices do 4 cells independently at a time, so 1 cell per hour average.

I have 2 testers, so, 8 cells at a time, 6 times a day (less because I sleep), so, 48 cells a day.

I tested every day for probably 2-3 months. And I have 2-3 months ahead of me if I want to do the next batch.

Also, where can I find 7000+ recycled 18650 cells?
You can't really anymore. There are enough outfits who've bought up all the recycling contracts. Laptops don't use 18650s anymore, so tool packs are your only source.

I worked out a sweetheart deal with a manufacturer to get mine, but the facility has since gone under so I haven't got any more in the last year or so. So, what I got is what I got.
 

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What part do you have a problem with? 2500mah that can discharge at 10c. It’s not a laptop cell, in fact it’s a cell for power tools. It’s been superseded but at a cost, the fact there older tech makes them a good price for high discharge cells.
 

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Hi Matt,
How reliable are these cells and how can I check their viability?
How do you want to measure reliability?

How can you check them? With a lithium-ion capacity checker.

If you pre-charge and post-charge and only use the capacity checker for discharge capacity testing, it takes about 4 hours per cell. Usually devices do 4 cells independently at a time, so 1 cell per hour average.

I have 2 testers, so, 8 cells at a time, 6 times a day (less because I sleep), so, 48 cells a day.

I tested every day for probably 2-3 months. And I have 2-3 months ahead of me if I want to do the next batch.

Also, where can I find 7000+ recycled 18650 cells?
You can't really anymore. There are enough outfits who've bought up all the recycling contracts. Laptops don't use 18650s anymore, so tool packs are your only source.

I worked out a sweetheart deal with a manufacturer to get mine, but the facility has since gone under so I haven't got any more in the last year or so. So, what I got is what I got.
Thanks so much Matt--your answers are always so thorough. Really appreciate the input 👍👍👍
Greg.
 
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