This tube inspired me to take a stop by our local Best Buy, Home Depot, and Lowes in search of cells. So… Best Buy had not a thing that we cared about(I went with a friend I got into flashlights). It was filled to the brim with AAs and a little rummaging revealed a shoddy flat power bank so it was a bust…. Next was Home Depot, and after asking several employees we almost thought they didn’t even have a battery bin. It is marked online that they have a bin, but it isn’t a traditional one, but just a series of cardboard boxes filled with various drill battery packs… I had a friend that worked there ask someone if we could just take them all and he said sure so we walked away with 2 boxes of assorted batteries. Lowes had the most conventional battery bin, probably because they had just built it. This time we hit the employees with an educational shtick that we were looking for cells in order to help with our educational robotics program and they said sure take whatever we have, SCORE. Sadly all they had were these Motorola NIMH packs, but as I suspected they each contain 6 NIMH AA sized cells.
Onto the haul:
Unfortunately only one of the drill packs was Li Ion and had 10 of these 18650s
They all registered at around .5 volts so pretty dead. From battlebots in high school we used A123 and other Lithium cells we would often have cells drop below the “safe” voltage and just force charge them until they hit the required voltage. I have managed to get 1 of the 18650s up to 4.2v, but they all seem to have this problem where they are constantly discharging so I expect either a protection has blown internally or maybe they have external circuitry to blame? The one cell I charged was the one that discharged the slowest, the rest would discharge at a rate near 0.01volt per second so I didn’t even fiddle with them. I’ll see if the one that I charged holds a usable charge over the course of a few days, otherwise it’s not really worth keeping around. I did not take any pictures of the NIMH AA cells, but they all seem usable I’ll try to charge a few and test if they hold onto it or can power stuff. I’m not well versed in NIMH do they have a voltage they shouldn’t drop under?
All in all, it was a great first time haul. Anyone have ideas for all the nicad cells I got? A lot of the 14v packs measured in at around 13.3volts and seemed healthy. I just didn’t tear into them because I was only really interested in the 18650s, which incidentally we got the least of.
edit: also got what looks like a brand new never used electric scooter lead-acid battery along with a very-used lead acid battery. We have plenty of fodder to give us an excuse to start frequenting the bins…