powerbanks

[amalan11]

Hi..could someone explain how a powerbank works? I have a samsung gallaxy phone and tablet and was looking at one that is 10400 . How do they work ,im assuming  you just plug it in to tablet by usb charger cable and it gives extra  power but im wondering how much longer time it gives and once the  powerbank battery is flat do you recharge it or is that it?

Thanks

[cq_tech · Accepted solution]

That's exactly how they work but as far as extra time is concerned, that depends upon the capacity of the power bank, which is usually powered by up to 4 or more 18650 Li-ion batteries. They normally have 2 x USB 5V outputs and when they run low, you simply recharge them via a mini-USB plug and wall adapter.

10400mA is quite a lot of storage and I'd expect one of those to provide enough power to run a phone & laptop for 24 hours or longer. Most people use them to charge their devices when away from mains power but they can also be used to conserve your device batteries as well.

[amalan11]

Thanks for that info,thats what I need

[transport-posters]

Watch out for ones from China.  I got a 5,000 mAh one for my 1,500 mAh phone battery and it only gives me about a 20% boost after being fully charged.  The seller simply apologised and refunded me.  It annoys me they are selling fake stuff and don't acknowledge it but simply apologise and refund when caught out.