Review: cheap 18650 mobile power bank

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chiefinspectorfinch
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Hard to tell, but according to http://www.chongdiantou.com/thread-2307-1-1.html it’s not very good…

Society is like a pot full of nuts and bolts, finest pieces always end up on the bottom...

 

USSR
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keep in mind that 1 amp at usb output means at leat 1.5 A from the battery ..

as voltage is boosted from 3.7 to 5 volts and include some boost circuit inefficiency etc.

on another power bank i did a test and at .9 amps usb output it was sucking 1.5 amps from cell and as the cell drained below 3.7 the current from battery increased to 1.9 Amps..

so if you are using laptop battery pulls i would recomend using a 2 cell model to increase efficiency..

their charger section (to charge the power bank itself ) seems to be using  a linear charger which makes the ic hot..

 

 

WarHawk-AVG wrote:

Yes, per the data sheet, it eliminates two separate channels worth of electronics and soldering

invisiblejules wrote:
Can anyone recommend some good batteries to put in these? Ideally something under $6? Thanks!

I am planning on using laptop pull panasonics (or sony [the red ones])

Decent enough and can handle 1A charge and has enough mAh to actually be worth it

 

 

 

Ohm711
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Bought cylinder style power bank for one 18650. It have small board with only one chip. Price was only $1.5. Quality of aluminium case is amazing.
Board have chip marked as MP3401 (same board as in post #147) and I did some measurements with this power bank. Stand by current is 116uA. Output voltage with no load is 4.98V.
When charging internal battery red LED is flashing. When charging is done red LED glow solid. Internal battery is charged to 4.17V. When charging power bank is little warm. PB drains from wall charger 0.7A and after while current starts slowly drops and continue. Charging time was about 5h (2500mAh battery).
I tried charge my phone (Lenovo Z2) with 3000mAh battery. I put 3400mAh (NCR18650B) battery in power bank. Phone have 15% charge at start. Charging stop at 84%.
When charging phone blue LED glows. When voltage of internal battery is under 3.2V blue LED starts flashing. Cutt of voltage is 3.0V
If I charge my phone from wall charger, current is 1.4A. With this powerbank was current 1.1A and voltage droped to 4.7V.
With this high current is chip very hot and after white whole PB is warm, but it work, no smoke Smile
Efficiency for output current 0.5A is 88%, for 1A is 80%. Measured with fully charged battery. When battery voltage droped efficiency was 75%. Tested with cold PB. Maybe is hot is efficiency even lower…
Output noise with 0.5A load is 6mV Rms and 24mV Vpp. With 1A load noise is 16mV Rms and 66mV Vpp.
For this price is very good product. It have good protection, so it will not over charge or over discharge you battery. Maybe will be good to disconnect data pins. Phone will detect this charger as USB and output current will be 0.5A. Charging will be slower, but much more efficient and chip will not be so hot.

Mildaine: I am almost sure you have bad battery.

(sorry for my bad english, it might help to somebody).

Halo...
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Welcome to BLF Ohm711! Beer
Thanks for the detailed review. Where did you buy your power bank from? Link?

Ohm711
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I bought it here: http://www.aliexpress.com/item/1pc-powerbank-Portable-Mobile-Power-Bank-USB-1×-18650-Battery-Charger-Case-for-Phone-for/32329517970.html
Many shops and sellers sell this item. But you can’t be sure which board will be inside.

Pregulla
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Sounds similar to what I’ve bought from GB. Except my chip has no markings.

phlowcus
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Almost same post as #145, only in reverse:
Now Gearbest sells a new Miller-ml-102-style 18650 charger, which is advertised as charger only but looks as if it could be a power bank as well:

http://www.gearbest.com/chargers/pp_177257.html

Thoughts?

Pregulla
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At that price i would just go for original ml-102

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