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jbard

1377 posts

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+1 received by user: 17


#213937 19-Apr-2017 21:52
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Looking to buy a powerbank and found this one at The Warehouse

 

 

 

For a 10400mAh powerbank this one seems to be at least 50% cheaper than anything I could find at PB tech or other shops. 

 

The closest I could find is this one for $69 at JB HiFi.

 

 

 

The only catches I can see is it charges at 1A so it does take a while to charge, and only one of the output ports is 2.1A. 

 

Still it seems really cheap compared to other powerbanks on the market?


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tripper1000
1648 posts

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  #1771512 27-Apr-2017 20:25
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Hi guys, rather than just slag this unit off without any concrete evidence, I decided to try test one out.

 

First I left it to change for 12 hours after the 4 battery level LED's indicated that it was full.

 

Did a discharge testing using a Turnigy Accucel 6 battery charger/discharge which has a max discharge rate of 1amp. Test was set to finish once output voltage sagged to 4 volts.

 

First discharge test at 1 amp on the 2.1 amp output port produced a 5v capacity of 6474 mA/Hr.

 

2nd discharge test at 1 amp on the 1 amp output port produced a 5v capacity of 5948 mA/Hr. I only let this charge for a few hours after the LED's indicated full.

 

Voltage regulation was good and did not sag below 5 volts when loaded at 1 amp, measured at the back of the sockets, however my cheap USB leads were dropping about 0.4 volts - that isn't the battery banks fault though.

 

The unit has 4x 18650 cells in parallel.

 

The 2 output port are independent from each other - when only one was in use, the other was 0volts.

 

The D+ and D- pins are open circuit which will leave BC1.2 compliant devices confused as the the output ability of the power pack. These pins should have combinations of resistors and short circuits to signal the instantaneous output rating of the power bank. Ref this link.  I checked 5 other devices I had laying around and 3 had shorted d- and D+ pins indicating 1.5amp output or more and 1 had resistors indicating 500 mA output. 1 had nothing.

 

The unit uses some kind of electronic detection to determine when something is plugged in and power up the 5 volt output. It doesn't have any kind of mechanical switch to detect when there is a lead plugged in like some power banks do.

 

From here I intend to repeat the tests at 0.5 amps discharge rate and also do a discharge test of the 18560 cells directly to see if they are close to the 10500 mA/hr rating on the case. I will also hook a 2 amp load up to ensure the 2.1 amp output is up to spec.

 

 Click to see full size

 

 


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