SL500 Battery drops to 96% (not using battery) [ Edited ]

[drcru]

I've noticed lately that my battery meter has dropped down from 100%. My machine is always plugged in and I seldom use the battery yet it had gone down to 97% and now 96%.

It also reports that the battery condition is still "good."

The only change I've done recently is upgrade to Windows 7, any ideas on what's goin on? This laptop is only about a year old (possibly nearing two).

I also managed to charge it to 100% after using up the battery but after awhile it drops back to 96%.

[Maliha Community Moderator]

Hi drcru,

Sounds normal to me, my macbook also does the same, I think the power manager is not able to precisely report remaining percentage, it just provides an approximation. Nothing to be worried about.

Hope it helps.

[drcru]

Are you sure? It was always at 100% before now and it actually dropped to 95% earlier.

[Maliha Community Moderator]

Yeah. This is to protect the battery from premature failure, from overcharging and accelerated cycle. Once the battery is fully charged to 100%, it will stop charging until it hits around 90% then it will start charging again. This is hard programmed into SL batteries since there is no way to set battery thresholds as seen on other thinkpads namely T series.

Hope it helps.

[drcru]

Alright, sounds reasonable. Thanks!

[Cody_bites]

my battery used to last for 4hrs but then after using for a couple of months, the battery reduced to 2hrs as soon as i starts using it for like 15mins. all the setting are the same, no changes made. what happens? 

[Maliha Community Moderator]

Hi Cody,

Welcome to the forum!

How many cycles been done on this battery? Tell us more about your system, 7 character product number e.g. 2668-KHU from the bottom will be suffice.