If you know where to look, you can have a very good success rate.
I recently went to a scrapyard and picked up 104lbs of laptop computer batteries. 50lbs of those batteries were all the exact type of laptop battery. It turns out a public school had stopped at the scrapyard and dumped off over 50lbs of laptop batteries there along with some other computer equipment, only for me to pick up the batteries later. My guess is those laptops spent their days being plugged into the wall, thus they were never used. Of those 50lbs of laptop batteries from this school, I have had an over 70% success rate. But let's break this down further:
10% were DOA (0v, rusty cells)
10% tested to have >1000mah and were rejected
10% were tested to have a capacity of around 1500-1900mah
70% were all tested to be good cells above 2000mah.
When I was tearing apart these laptop batteries they were all the exact same levono battery. But it looks like levono had gone shopping, as I had found several different brands of batteries with the same capacity inside each laptop battery including but not limited to:
LG BB4 2600mah
LG BB3 2600mah
Sanyo UR18650FM
Samsung ICR 18650 26D
Panasonic CGR18650E
The Samsung cells I have had very good success rate, most are testing to be over 2500mah, so practically new. The panasonic cells come in second. Their cells have tested every single time to be above 2000mah per cell, with none going below that. The sanyo cells come in third. Most of those cells are tested to be around 2200mah, although there are a few outliers that are only doing 1500-1700mah per cell. The LG BB3 and LG BB4 cellls are performing all over the place. One day I get cells that are above 2400mah, other days the cells are under 1700mah, although the majority seem to be around the 2000mah mark.
I guess it just goes to show you that at least in the late 2000s, samsung built the longest lasting 18650s, with everyone following.
cstanley said:
What has been your guys average success rate when harvesting cellsfrom old laptop batteries? So far, I have got 10/41 cells (25% success rate) out of 7 battery packs so far. I have 43 more laptop batteries to go, so maybe my success rate will go up. This seller on ebay posts lots of them, however some are generic so I'm not sure if I will continue buying from him.
I have been setting aside batteries that have a lower than 3v, some of them have less than that. I haven't tested anything else yet (capacity, resistance etc) - what are your other limits?
Also, if you want the best deals possible, skip ebay. Go to your local scrapyard. I was able to purchase laptop battteries for $1.25 PER POUND. not per battery, PER POUND. Even after fully testing all the cells it means I paid only about 30 cents per cell. You are never going to find a price that good on ebay.