Techie question about power banks

JonathanRyan

JonathanRyan

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OK, this should be an easy one, but Google just wants to sell me things.....

If I have a phone with a 950 mAh battery (don't laugh) and a power bank with a 10,000 mAh capacity, does that mean the power bank can charge the phone a little over 10 times?

I.e. is battery capacity like a bucket of water? I can just pour power from one device to another and the number of times I can do that simply depends on the relative "volumes". Or is it more complicated than that?
 
JonathanRyan said:
OK, this should be an easy one, but Google just wants to sell me things.....

If I have a phone with a 950 mAh battery (don't laugh) and a power bank with a 10,000 mAh capacity, does that mean the power bank can charge the phone a little over 10 times?

I.e. is battery capacity like a bucket of water? I can just pour power from one device to another and the number of times I can do that simply depends on the relative "volumes". Or is it more complicated than that?
Click to expand...

It's much more complicated since the "power bank" mush have a significantly higher voltage than your battery or no current will flow unless it uses a form of dynamic transformer to step the current up.

It must also have an extremely good method of monitoring the flow of current so it isn't excessive and is cut off before overcharging occurs.

It also depends on the type of battery used in the "power bank".

So whether it would actually charge your phone 10 times or more depends on the electronics but most probably not.
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In simple terms, yes......pouring a large bucket full into a smaller vessel.

However, the nirvana of battery design is that it can deliver full power until exhaustion. Lion battery technology has AFAIK gotten close but not 100%.

So, it is unlikely you will get 10charges because of the above aspect......plus the phone charging circuitry and the ''supply control" circuitry in the power bank will affect rate of charge and deliverable power i.e. not as simply as the bucket analogy.

All the above is a summary of my understanding and I look forward to greater insight as to the finer details of the battery & power control technology.
 
more to the point is what they say on the power bank and what is reality
a lot will have a 10 amp hour rating but the nominal figure is closer to 6 amps
the last one i bought ( mixxi powerlife ) had a rating of 10 amp hour and 6 amp hour nominal, when tested it produces just over 6 amp hour which as far as it goes is within spec

the li ion cell within the power bank ( and most other power banks ) is 3.7 volts there is circuitry within the power bank that regulates the voltage up to 5 volts for USB charging purposes,

the reality is most of these 10 amp hour power banks will charge the average phone about 4 times before they need re charging

if your thinking of buying one buy one from a reputable manufacture some of the chinese cheap ones are not what they seem to a point where batteries are replaced with dummies to bulk the product out and claim some ridiculous power rating
in reality they might have one or two cheap cells and the rest is padding
 
I use anker power packs, the current one is about 20,000mAh, this one to be exact.
https://www.amazon.co.uk/gp/product/B00VJSGT2A/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Now I don't know the science behind just how many charges you would get, but I was happily surprised earlier in the year when I went on a 2 day trip to Italy and Germany and forgot to pack a plug adaptor. Gave my phone (LG V30, circa 3500mAh battery) four or five recharges (hammered the phone over three flights watching movies) and still showed some power left in the tank when I got home.
 
bass_junkie83 said:
I use anker power packs, the current one is about 20,000mAh, this one to be exact.
https://www.amazon.co.uk/gp/product/B00VJSGT2A/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Now I don't know the science behind just how many charges you would get, but I was happily surprised earlier in the year when I went on a 2 day trip to Italy and Germany and forgot to pack a plug adaptor. Gave my phone (LG V30, circa 3500mAh battery) four or five recharges (hammered the phone over three flights watching movies) and still showed some power left in the tank when I got home.
Click to expand...
I have the exact same one, and can't fault it aside from it being quite a big solid lump. Daughter has a small cheapo Chinese one which never seems to do its job properly..
 
Thanks everybody. FWIW it's an oldish Anker powerbank which actually seems to charge my phone faster than a wall socket. Reading some of Anker's specs that's actually not impossible.

I'm going to be away from power for a couple of days and need to charge my phone and would really like to charge my GPS watch (which doesn't say how big the battery is but it's physically so small it can't be much).

If I can charge both 4 - 5 times then I'll stop worrying :)
 
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