I bought a 5600mAh external battery for my iPhone 5. It doesn't have an indicator of charge percentage (don't get smart, yes I know, iPhone shouldn't be mixed with non genuine Apple merchandise and all that jazz :)). How long should I charge it for on my wall outlet? And, how can I know how much is it charged, without buying additional equipment to measure that?

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    If it's a lithium-based battery chemistry, it should already have all the safety and management circuitry it needs to be safe to use. Even cheap NiMH chargers monitor the charging process and react to changing charging conditions such as changes to current or voltage. – user Nov 18 '16 at 14:24
  • Ok, but why was it hot when it was plugged into the ground electric plug (in the wall), and it is not getting hot when I plug it into laptop, on laptop's usb port? – Vladimir Despotovic Nov 18 '16 at 14:35
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    You would be wise to just plug it in to an electrical socket anyway. You're just draining your laptop battery to charge another battery, and a wall outlet would likely be faster too. – Kaizerwolf Nov 18 '16 at 15:49
  • I will edit my question to specify that I only want to charge on wall, not on laptop. Thanks for the advice. Do you know how long would I have to charge it (since this is my original question)? – Vladimir Despotovic Nov 18 '16 at 18:19

Your USB ports are probably supplying between 0.9 and 1.5 Amps.

Think of Amps as "amp hours per hour" or "thousand mAh per hour."

Therefore you should need to charge between 5.6/0.9 (3:45) and 5.6/1.5 (6:15)

For info on your specific configuration check out this site:


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