General wear and tear question regarding laptop

[namaiki]

Might also partially be caused by transparency being disabled for the taskbar.

[leslieann]

actually the purpose of the Sony battery care is to limit the heating. I am not aware of any electo-chemical or mechanical preference for 50% in LiIon. What mechanism are you supposing for this 50% theory?

Max charging causes heating, more than a lower level charge, but that isn't the point, especially when you have a heatsink half an inch from the battery that will heat it regardless of what the battery is doing.

As to the 50%, I've seen it on quite a few manufacturer sites in regards to shipping and storage.

A quick Google search turns this up as the second hit and meshes with what else I have read on it from experts and manufacturers. I'm sure if you look, you can find more to back it up. Search for "li-ion storing".
How to Store Batteries – Battery University

While lead acid must always be kept at full charge during storage, nickel- and lithium-based chemistries should be stored at around a 40 percent state-of-charge (SoC). This level minimizes age-related capacity loss while keeping the battery in operating condition and allowing self-discharge.

Finding the 40 percent SoC level is difficult because the open circuit voltage (OCV) of batteries does not lend itself well to state-of-charge estimations. For lack of better methods, voltage is nevertheless used as a rough fuel gauge indicator. The SoC of Li-ion is roughly 50 percent at 3.80V/cell and 40 percent at 3.75V/cell. Allow Li-ion to rest 90 minutes after charge or discharge before taking the voltage reading to get equilibrium.