The laptop has been 4 y o. The battery can only last for one hour.
Today I decided to make some other use of it,so I destroyed it.Here is picture.
I replaced the original red shrink,now it looks like a new one. 
At 11:30 am,I put one battery into C8,now it's only 12:00,still on high.I will test the mAh later.
They are Sanyo. What colour on the positive end?
in positive side, there is a green ring.
on the body,
X NB8Y36
006366
Edit: saw the reply after I submitted my reply. I haven't encountered a Sanyo cell with a green ring. But those manufacturer numbers are still indicative of being a Sanyo cell.
I agree with Caleb there, the glossy red heat shrink is also indicative of a UR18650FJ, just gotta see the positive end though.
not sure about that, I thought they were Samsung ones.
Interesting. I’ve seen some Samsung packs that claimed to have Japanese cells, but I haven’t torn into any (yet). This confirms that Samsung has sourced cells from a competitor…
Is this to say,Samsung admits that Sanyo batteries are better?
No both cells are just as good as each other. It’s probably just cheaper to put these cells in. They are all about profit margins.
Most old red sanyos have the model number raised (stamped ?) on the heatshrink and you can feel it with your fingertips .
nice spam links hidden in your first post.
btw reshrinking cells that have damaged wrappers is safe.
i probably just wasted some electrons on a spammer bot though….
btw the spam code shows up in the quote.
and as to sanyo cells in a samsung laptop most laptop oems farm out the packs with their specs.
sometimes the pack makers brand is on the pack somewhere.
Well I think a few years ago there was a Samsung or LG factory that burned down so there were some supply and demand issues.
The other possibility is that Samsung simply contracted out the pack making to a third party factory that simply chose what cells to use.