Progress on my cell testing

Hey everyone, just wanted to share my progress you fine people.


~26 cells from 1000-1500Mah
~95 cells from 1500-2000Mah
~152 cells over 2000Mah.

~100 cells were bad as in at 0V, heaters or below 1000Mah, or all three.

I charged them all to 4.2V and let them sit for a couple of weeks. Anything that dropped below 4.1V during that timeis considered 'bad'.

I am very surprised I got so many good cells considering I paid $107 CAD for 51 lbs worth of 'scrap' laptop batteries.

That means I paid about $0.40 CAD each cell. Considering new PKCELL's @ 2200mAH go for $3 CAD each, I'd say this is quite good.

In fact, I got so many good cells, I'm wondering if I ever need to buy new cells as I had intended. My thought was I'd use used cells for testing / practice and then when serious about doing a project, to purchase new cells. Thought it might be worth it if I included my time breaking down those laptop batteries but it wasn't a lot of work.

There's waaaaay to much empty space in that container. Get busy!

That's a pretty good price.
4.1V is a good cutoff, I'd say. I put mine to the side and then I'll do another charge on them later. Maybe the second time they'll hold a charge for a longer time (one hopes)

Just remember that any cell that has low voltage could still be really good. Just give it a chance. Slow charge it (<=250mA) to about 3V, then go into a normal charge mode. 1000mAh cells are good for flashlights And heaters are good for hand/foot warmers jk!

Good haul, tho. I started off with a small batch myself. I now have 3 containers about that size full. I still need to capacity check (lazy bum I am). At least they'll have sat for awhile to get a good read on self-leakers

This is my first 'kick at the cat' so to speak. I have a history of starting projects and not finishing them so I'm starting slowly and then working my way up once I get more comfortable. I have no plans on building a powerwall just yet as I have a LOT to learn before I start on something that large.

4.1V is going to be my max once I get a BMS and build a 48V battery pack for an e-bike. I've already bought the BMS, just waiting for it to show up. It's the same 14s BMS daromer tested and it has BT and support for Android so it seems very good for that price. Then I plan on building a 12V battery for testing using my worst 'good' cells and then purchase an inverter.

Maybe it's time to buy another $100 worth of laptop batteries.

Very cool. I started out finding old laptop packs and they have been a mixed bag most of them within 20% of new capacity. I did purchase a box of random laptop packs and got lots of junk. About half the cells were under my 2000mah limit. The rest were fairly good cells. But time will tell.

I have started 2 projects with the less than 2000mah cells. 1 being a 7s16p pack for my electric lawnmower which works awesomly. Generally only draws 10amps and that's under massive load on the blades. Lasts me a full cut of my front and back yards (really small) and the pack gets down to 3.7v from 4.15 where I charge it to.

Perhaps I got lucky or is it a result of the environment? I live in a dry province in Canada so perhaps that helps.

Your 24V lawnmower sounds cool. I'm thinking now I should do something related to snow removal. ;D

I'm also in Canada EH! and Yea Snow would be cool but the power required to move that shit is much much more. Checkout RCadventures on youtube. he has a 1/10th sized Snow blower that is 3d printed. take lots of power for something soo small. to scale it up you need lots of amps. There was also a ugo (6 wheeled atv type thing) that someone converted to a plow which would be cool

jdeadman said:

I'm also in Canada EH! and Yea Snow would be cool but the power required to move that shit is much much more. Checkout RCadventures on youtube. he has a 1/10th sized Snow blower that is 3d printed. take lots of power for something soo small. to scale it up you need lots of amps. There was also a ugo (6 wheeled atv type thing) that someone converted to a plow which would be cool

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They already make battery operated snow blowers so it can't be that difficult. Just adds more volts right?

Snow blowers are power hogs delux! It takes HUGE amount of power to move a little bit of snow. There is reason those big snow canons on trucks demands 500 or even 1000Hk to throw it a bit

I have a smaller one here that takes like 30cm in width... It have to push really really hard with its 5.5Hk motor and then i cant have much depth nor push it hard forward

Yea those electric one are ones that run off AC with a fairly low torque motor. it just gets spinning so fast that inertia takes over till it bogs down. But a proper 2 stage blower would be cool. A High torque DV motor would be great for this as it has the grunt but it will need the amps behind it. I'd be looking for a old clapped out electric forklift and start from there.

For snow removal, I'm likely not going with something battery operated but corded as it makes the most sense and cents.