The word "drain" refers to the act of removing or letting out water or other liquids from a place or container, usually through a pipe or some kind of opening. Full definition
And in previous devices, that's sometimes the thing that I will notice a little bit of drain on the battery life. (techrepublic.com)
This processor has a clock speed of 1.2 GHz and gives you maximum performance without draining of battery. (flipkart.com)
There are some drawbacks to this configuration, such as battery drain on the smartphone or tablet, but the low price point has made it a very attractive option for consumers. (androidheadlines.com)