EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: Starlord on February 22, 2015, 09:02:34 am
-
A friend of mine bought a cheap 12V LiPo pack from China and after the first charge, it died on him. I cut it open to investigate and as expected there were three rather small cells in a battery advertised as 9800mAh.
I was hoping to find out what the capacity of the individual cells really was, but to my surprise they don't say, and the numbers on them are indecipherable. Also, it appears one of the batteries is different from the others, perhaps having a different manufacture date. It's the same size and shape of course.
Anyway, here are the numbers on each cell:
C2917 QHC 5C2
120809 C07369
A2956 BGP 3C2
110720 B05995
D2888 QHC 5C2
120810 C04998
I'm guessing that 110720 is a date code. YYMMDD. If so, that would mean these batteries were manufactured quite a while ago.
I have no idea what the other numbers might mean though.
-
Off the top of my hat:
5C2 means that the capacity is 2000 mA and the max discharge current is 5 times the capacity.
-
120810 is size code, in mm.
12 x 8 x 10 mm is... nearly cubic, and nowhere near enough volume for anything close to 9800mAh. Not to mention all 3 cells having slightly different dimensions, and the middle cell being 20mm in its 3rd dimension... no.
-
120810 is size code, in mm.
12 x 8 x 10 mm is... nearly cubic, and nowhere near enough volume for anything close to 9800mAh. Not to mention all 3 cells having slightly different dimensions, and the middle cell being 20mm in its 3rd dimension... no.
Yeah, they're not cubic. :)
But I also doubt they're 9800mAh. I suspect they added the mAh of the three cells then wrote that as the capacity even though they're wired in series.
And their actual size is 90x35x5mm.
-
You can post a photo, and maybe I can even tell you which company made this battery.
There is no other identifying text on the individual pouch cells than what I wrote, and otherwise they look like any other pouch cell. The batteries came in a generic blue box. Search Ebay for 12V CCTV 9800mAh and you'll see a bunch of them.
-
Hello,
You could do a single discharge test to test the capacity. That wont tell you the brand new capacity, but it will tell you the current capacity of the cell.
You might also consider the dimensions as compared to another cell and see if you can estimate the capacity when new.
-
The battery is dead and won't take a charge. That's why I cut the thing open. :)