How is Battery life related to Cycle count?

[atx-88]

The battery on my T40 has a relatively low 47 cycle count but has only 22.3 wh left out of the original 47.52 wh. Is this normal? Battery info shows it was first used in 2003-2004. Does age automatically cause capacity to diminish due to the internal chip setting? Battery health is currently "Red" and doesn't change even after I re-condition the battery by letting it run down to zero. Any ideas or suggestions?

[darkwish]

Li-ion batteries lose capacity with age, whether you use it or not. They also lose capacity the more cycles it has gone through.

[byunnbi]

When I got my t41p last year in March, my 9-cell battery had about 35 Wh left out of 71.8. I had the same problem as you, darkwish. My cycle count was already up in the mid 100's, too.

This may help... try completely discharging the battery a few times; I found that when i got down to about 5.5% battery left, RMClock would tell me I had ~15 minutes, but I actually got about 43 min. and the 5.5% didn't go down at all for that entire duration! (Just did this recently, actually). My battery as of 2 weeks ago had degraded to a measly 25.9 Wh, and after I applied this tip 4 or 5 times, I'm now back at 39.9 Wh, more than what I began with when I first got my TP. My cycle count is now up to 208 as well. Hope this helps.

BTW, recently, I pulled the same trick AGAIN, but it stopped at 4.5% as opposed to 5.5%.

[jdhurst]

<snip> Battery info shows it was first used in 2003-2004. Does age automatically cause capacity to diminish <snip>

Your battery is old. So is mine. They need replacing. Next?
... JDH

[tyito2000]

I have a cycle count of 335 with 19.07 watt hours (orginal 47.52 watt hours). The battery health is "green." The reason I have gotten the battery mileage is is that I have over 35 years of following the evolution of rechargeable batteries.

The key is to fully cycle the battery to empty, before recharging. There are times when you can't do this and need to recharge from a partially full state. However, you should fully cycle the battery soon after.

I understand that Lion batteries are not suppose to have a memory effect. However, based on several years of maintaining batteries at peak performance, you should always cycle your batteries to empty, before recharging.

BTW, age diminishes capacity. However, you can acheive a much higher cycle count and better health if you properly cycle your battery.

Also, for those of us that are paranoid of Sony battery cells, you can have your old T4X battery recelled with higher capacity LG battery cells at batteryrefill.com.

Tom

T42P
1.7 ghz 745 Centrino
2 gig ram
80 gig Hitachi HD
ATI Fire 128 GL
SXGA+ 1400x1050
Fingerprint reader
Win XP