Good idea to periodically drain a USB battery?

Just picked up a new external USB battery from Anker. It wont get a lot of daily usage but I want to keep the battery in optimal condition.

  1. How often should I look at draining the battery and to what level ?
  2. Suggestions on what to use to drain the battery ?

I have seen anything from a resistor to a USB based device with a meter built in that can place a load on the battery.

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I believe Anker recommends fully draining and recharging the battery every 3-4 months to maximize lifetime.


I do this once 3 months on my Powercore 5000 and couple other Powerbanks…

Best way to discharge during a hot summer day (it’s 96 degrees here today) - connect a USB fan and place it to discharge 100% :sunny::sun_with_face::dark_sunglasses:


Just echoing what @Insider and @Shenoy said. If I haven’t used my powerbanks (Powercore 5000 & 21000) in a while, I’ll drain them & then recharge them.


Great info. I wasn’t aware you are supposed to discharge them even if you don’t use them

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Nice and thanks

Good info.

I had forgotten, but now remember! :wink:

Thank you.


Lithium ion batteries don’t like to be drained all the way to 0%. It would be best to drain it to about 30-40% (usually 1 or 2 LEDs remaining on the battery gauge) and then recharge it. The idea is to keep the electrons moving once in a while in the battery. If you don’t plan to use the battery for a long time, store it with a partial charge (50-75%).

Some additional reading:


Very good information and great question! I use a USB reading lamp that does the job, takes a while to drain a 26800 battery but it works. Check it out, it is also a great travel companion for deployments USB Reading Lamp with 2 LED Lights