锂电池忌讳的就是深度放电。用完再冲不会延长电池寿命的。
http://www.techrepublic.com/blog/five-apps/five-tips-for-extending-lithium-ion-battery-life/
3: Allow partial discharges and avoid full ones (usually)
Unlike NiCad batteries, lithium-ion batteries do not have a charge memory. That means deep-discharge cycles are not required. In fact, it's better for the battery to use partial-discharge cycles.
There is one exception. Battery experts suggest that after 30 charges, you should allow lithium-ion batteries to almost completely discharge. Continuous partial discharges create a condition called digital memory, decreasing the accuracy of the device's power gauge. So let the battery discharge to the cut-off point and then recharge. The power gauge will be recalibrated.