Anybody know smth about these 2800mah Li-ion cells?

[junglemike]

Hi. I've got some old laptop - 10 year old Toshiba tecra pentium1 133mhz.
I was playing with it, and I discovered to my big surprise that I hold battery charge for full 3 hours!!. I have some experience with computers and li-ion batteries, and I know that usually Li-ion batteries don't live more than 3-5 years.
I was so surprised that I had to open this battery up and see what's inside. I was 99.9% sure that i would be 18650-form factor li-ion cells (as in majority of laptops) - But no. It is some new type, unknown to me. Couldn't find much info in the internet also.
As you can see in the picture - these cells are much fatter than 18650 cells
Red and gray cells at the bottom, as well as orange cells to the right - those are standard 18650 cells for comparison. These huge sony blue cells read "us26650 sony energytec"

http://img214.imageshack.us/img214/4713/2800mahto3.jpg
It is 3s2p battery pack, which makes single cell to be 2800mah.
And this is 10-year old technology!!!
Can you imagine what mah could they be if manufactured recently.
In those day 18650 li-ion cells were maximum 1400mah per cell
Today you have LG 18650 cells which are 2600mah.
This means those cells could easily fit 5000mah. That's insane. Imagine a flashlight or a laptop on such cells.

 

[Supernam]

Hmm... 26mm diameter is same as a C cell I think, and 65mm is the length of 2 CR123's or 2/3 of 2 AA's.

AW has 26x52 (50mm without PCB). So the ones you found are like long C cells. If you could build a PCB into it (or run it unprotected), maybe you can shove 2 of them into a Mag 3C body. Hopefully they have a capacity higher than AW's C's.

 

[2xTrinity]

Hmm... 26mm diameter is same as a C cell I think, and 65mm is the length of 2 CR123's or 2/3 of 2 AA's.

AW has 26x52 (50mm without PCB). So the ones you found are like long C cells. If you could build a PCB into it (or run it unprotected), maybe you can shove 2 of them into a Mag 3C body. Hopefully they have a capacity higher than AW's C's.

AW's Cs are 3 Ah in a smaller cell. They will probably handle higher discharge currents, as well. Batteries have improved in the last 10 years or so since that laptop was manufactured (I actually used to use that exact laptop, battery life I recall was great even after 6 years of use). Actually, a modern 26650 might be nice to have precisely for doing , it could store around 4Ah. Two of those in a 3C sized light would be awesoem for lighting up an LED array or a hotwire. Heck, a single-LED light running on a 1X26650 could have both high output and ridiculouslsy long runtime in a fairly small package (smaller than a typical 2C flashlight). As in, 900mA drive at the emitter, regulated, for over 4 hours. 350mA drive might last 12 hours, and a low level could last for several straight days regulated.

Big fat batteries like these may start to be necessary if Luxeon ever releases their 2A/500 lumen LED that they announced. Honestly, just from a geometric perspective it's a lot more efficient to pack in more juice by making lithium cells fatter, rather than make flashlights awkwardly long by stacking 2x18650, etc.

As for LiIon batteries being useless after 3-5 years of shelf life, I believe that has more to do with increased internal resistance than decreaesd capacity -- which is bad if you're planning on using old cells to light up hotwire mods, since what you care about there is pulling a lot of current out of them. For running a computer off of a big pack, the current draw is fairly low, so the increased internal resistance doesn't affect runtime very much, especially for non CPU-intensity work.