I need help determining how many lbs of laptop batts to buy!

[jitup]

Hello,
I have come across a source that is willing to sell me dead laptop batts at a minimum of 50lbs. I would like to harvest 100 usable 18650 cells for my batterey bank. Does anybody with bulk weight experience know how many lbs it takes to get close to 100 cells that work? Thanks for the help.

 

[Hillhater]

Is that 50lbs of cells,...or packs with the casing ?
50lbs of cells would be about 500 cells, which should enough useable "good" ones.
But you need to know what type of cell (capacity , brand etc) you are likely to get ?
Even 50lbs of packs should be enough at about 400 before sorting, but "harvesting" cells from that number of packs can be a real chore depending on what type of pack they are.

 

[bowlofsalad]

Hello,
I have come across a source that is willing to sell me dead laptop batts at a minimum of 50lbs. I would like to harvest 100 usable 18650 cells for my batterey bank. Does anybody with bulk weight experience know how many lbs it takes to get close to 100 cells that work? Thanks for the help.

https://www.endless-sphere.com/forums/viewtopic.php?f=14&t=2638 This thread is likely to contain a lot of useful information on this subject. To search just this thread, click the link and look in the upper left corner of that thread, there you will see a search box which is just to the right of the 'post reply' button.

I am not saying you shouldn't have asked your question, I am merely saying this in case nobody gives you an explicit answer here. I wouldn't be too surprised if your exact question has been asked or answered on that thread. If nothing else, this thread will yield tons of really useful information on the processes you are likely to use.

 

[teslanv]

Or this thread by DrkAngel

https://www.endless-sphere.com/forums/viewtopic.php?f=14&t=26383

 

[friendly1uk]

What you making?
36V 30Ah for a 250W pedelec?


Building with end of life packs is an ongoing process. Buying, stripping, testing, building. Then doing it again to rebuild every couple of months. With 100 cells of unknown age, all 4 year rated, a cell dies every fortnight. I read the threads from happy owners that do this all the time, but it wouldn't make Me happy

A bit back the bms board in some well known power tool packs was eating a small proportion of the pack while in storage. This lead to many returns where half the pack was actually new, and fit for high discharge. They would be a good source of cells. Laptop cells would surely be more concerned with energy density than discharge rates though. At 4p they might not power anything.

Do you know a lot about your source?

 

[999zip999]

Will be a lot of work. I would start with new cells as trying to sort use cells for an ebike battery. These is for a 60lb. Bike plus you and your weight. Not for a flashlight.
Just get a new battery and charger with bms and go ride.

 

[jitup]

Thanks for all the help so far. I have an ezip step through that is 450watt, if my math is correct I only truly need 84 cells, for a 7s12p for around 25-26v depending on cell health. The rest would be spares, or if my bike controler won't handle the 25-26v ill have to upgrade to a 36v controller. If that happens ill up the voltage of the pack. The reason I am interested in going this route mainly has to do with price. I can get batteries that still charge from a recycler for $1.05 a pound at a minimum 50lbs. The reason I don't just go ping is because I am pretty poor. I just got the bike and have 2 sla packs, which do the jobish for the daily commute up and down mtns both ways 10 miles each way. I am trying to prepare for when they die. I have ripped apar laptop batts of nimh variety whiles ago just to fix my own laptop, I needed 2 cells, a lot different than 100. This is for a daily comuter around 20 miles round trip. I am still trying to figure out how to bulk charge around 400 cells to test. Is there a link for how to do 100 cell batches? I am unsure of this is going to be worth all the effort or to build a batt from 5s lipo hobby batts. Hobby rc batts are a lot more expensive, but way quicker and easier. I would be cycling and charging the bike once a day around 20 miles 5 days a week regardless of weather. Any input would be great and I have learned so much from you guys. I would just hate to sink money into more sla batts when mine go if for a similar price can have better tech.

 

[jitup]

Thanks for all the help folks but I decided against used lappy batts going with konion instead