Old laptop batteries

I salvaged a lot of laptop batteries circa 2010, they were old by then. Presumably 5 years old or how many years old as a guestimate.
They don't throw away new equipment.

I parsed through the cells, and threw away about half, the ones that did not hold charge. The remaining ones I kept. I am not real sure of the original capacity, probably about 2000 Mah - just think 2005 or 2007-2008 time frame and you will have the right idea. Either a decade or even older.

I need to pull out the bag and recheck them again, I left them all charged, I need to parse them and throw away the ones that self-discharged.

I wonder what percentage of the original capacity they hold - which wasn't high to begin with. Not 3500 mAh you might say.

I also have a set of older 18650 that I got myself, new, circa 2010 and up. They are much higher capacity like 2900 and 3100 mAh cells, Panasonic. I still use these, along with the latest-greatest.

I wonder if I can use the really old ones 10-12 year old ones - in place of primaries. That is a one-time use. Since I have what seems to be 100 or more. and realistically they will just lay there and degrade into oblivion.

etc said:

I salvaged a lot of laptop batteries circa 2010, they were old by then. Presumably 5 years old or how many years old as a guestimate.
They don't throw away new equipment.

I wonder if I can use the really old ones 10-12 year old ones - in place of primaries. That is a one-time use.

Click to expand...

I presume you're talking 18650's, so I can only think they could replace a 2xCR123 primary configuration. Your light would have to handle the lower voltage of a single 4.2v cell, and fit the slightly different size of an 18650. But, there are many lights that can do that.

Also, make sure your light doesn't draw too many amps, but if it runs on CR123 you're probably okay. Most laptop cells back then have specs that indicate you should not charge them more than 0.5C, or discharge more than 2C. So, if they're 2000mAh cells, charge them at 500mA and don't use them in a light that requires more than 4A.

I don't know why you'd use them once and throw them away, though. If you have a battery analyzer, measure their capacities and use the best ones for your lights as rechargeable cells.

Yes, I am talking 18650. Though I did recover a small number of 17670 cells.

If you travel, some of them are so close to the end of their lifespan that they are not worth bringing back. Just throw it out/recycle if possible.

so on a trip instead of 20 primary 123 cells, you can get away with 10x18650 which will end up being about the same thing in terms of runtime.

I've had instances where some of them would not ignite high-powered torches. I think the only one I've had issues with has been M61HOT, due to its immense drain. Everything else such as M61, M61T and M61LLL has worked well - as well as possible given reduced runtime.

Well, it's free lumens.

I'm using about 16 Sony ~2000mAh 18650s from genuine OEM Sony packs. They are date coded 2002, so 16 years old.

I don't charge them any higher than 1A and I don't discharge them any higher than 1.5A, which is fine on my Convoy medium/low modes, where some of them reside.

I'm at about 75% (1500mAh) on most of them and have been pretty impressed. I have some Samsungs from a slighter newer DELL pack, that are doing about the same, although 4 of the 8 were recycled right off the bat.

That's one reason why we need analyzing chargers--laptop pulls.

Chris