Don't completely discharge those lithium-ion batteries!

There is still a lot of misinformation associated with charging Lithium-ion batteries.  Some people are still being told the batteries in their phones, tablets, laptops, etc. have a finite number of charge cycles and it takes from a cycle whether the battery is almost full or empty.  This would be true for some older types of batteries but not for Li-ion batteries.  Some systems will want you to cycle batteries (full to empty to full, etc.) in order to calibrate the power management software but not for battery life management. [more]

One battery resource says:

The smaller the depth of discharge, the longer the battery will last. If at all possible, avoid frequent full discharges and charge more often between uses. If full discharges cannot be avoided, try utilizing a larger battery. Partial discharge on Li-ion is fine; there is no memory and the battery does not need periodic full discharge cycles other than to calibrate the fuel gauge on a smart battery.

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

The exception to this is Li-ion batteries don't store as well if they're topped off.  That is, if you plan to leave one in storage without using it for an extended period of time, it's best to store it about half charged rather than completely charged.

General betteries. laptops