How does this battery bank work

[Legolessed]

I found a very interesting good in Gearbest：18650 Battery Charger Power Bank Case http://m.gearbest.com/chargers/pp_187287.html

[dantayy]

It's a portable charger. You charge the battery inside, and you can use the charged battery to charge your phone. Im suprised you've never seen this before. Look up "powerbank"

[Legolessed]

25 minutes ago, Ernest_L said:

It's a portable charger. You charge the battery inside, and you can use the charged battery to charge your phone. Im suprised you've never seen this before. Look up "powerbank"

i know what a power bank is but the battery type seems to be alkaline batteies not lithium