Tell me how this is possible for an old battery.

[Qing Dao]

I have a battery with an October 2008 mfg date, March 2009 first use date, 25 cycles, and over 95% of the original capacity remaining. Its capacity is 53.6wh from the original 56.16wh. The power manager battery test confirms this.

[RealBlackStuff]

If it's a Panasonic battery, then yes.
If not, please let us know who made it and give P/N and FRU.

[Qing Dao]

As a matter of fact, it is Panasonic. The FRU is 92P1139.

[ajkula66]

As a matter of fact, it is Panasonic. The FRU is 92P1139.

That's to be expected, then.

Panasonics last a *very* long time in most cases.

[Cigarguy]

Very lucky too as Panasonic cells are hard to come by.

[sktn77a]

Interesting - I have a 6 cell original battery in my 2011 T420 that says LGC (LG?) - 300 cycles and still has 56.41Wh (slightly more than the design capacity of 56.16Wh)!

?????????

[600X]

LGC is very good as well. We have a T60 Panasonic from 2006 with over 600 cycles and 60Wh left from 88Wh and it's still running strong.

[RealBlackStuff]

LGC (LG Chem) is part of the LG agglomerate in Korea, which also makes the LC LCD-screens.
They are in the same ballpark as Panasonic, where batteries are concerned.

[AIX]

It's seems that the late Panasonic batteries are no longer truly "longtimers". My T420s' Panasonic battery looks like that:

Manufacture date: 2011-05-29
First used date: 2012-03
Remaining capacity: 32.72 Wh
Design capacity: 38.85 Wh
Cycle count: 46
Panasonic 42T4847

[ajkula66]

^^^^^^

That doesn't sound right. Have you tried re-calibrating that battery?

[dr_st]

Panasonic and Sanyo have merged their battery business some time ago. Whatever has been true of the relative merits of their batteries before may no longer be true.

[sktn77a]

My T420s' Panasonic battery looks like that:

Manufacture date: 2011-05-29
First used date: 2012-03
Remaining capacity: 32.72 Wh
Design capacity: 38.85 Wh
Cycle count: 46

Actually, if that design capacity is correct, it's only lost 15% of its capacity in over 2 years - that's not bad.

[AIX]

^^^^^^

That doesn't sound right. Have you tried re-calibrating that battery?

Yes, I've tried, but didn't improve anything..

Actually, if that design capacity is correct, it's only lost 15% of its capacity in over 2 years - that's not bad.

You're right, not that bad for a 2 years battery, fortunately the wearing rate was pretty much stalling for the last year. Look what I've write ~2 years ago on NBR:

"I have realized that my (T420s' Panasonic) battery has now a full charge capacity of 36Wh after 2 months of use and 6 cycles " and then:

same behavior here: Lenovo Thinkpad T420s review
"Panasonic FRU 42T4847 Li-Ion 43.29 Wh 11.10V - ThinkPad Battery 66+ (6-cell) P/N 0A36287 rated for up to 5.5 hr. (not continuous use) after 14 cycles, full charge is only 36.64 Wh, hope it is isolated incident ..."

So, not really the Panasonic batteries we used to know. I'd say that the LGC is the new Panasonic.