Test/review of Dual USB Charger 2.1A

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HKJ
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Location: Copenhagen, Denmark
Test/review of Dual USB Charger 2.1A

Dual USB Charger 2.1A
DSC_0753
Official specifications:


  • Input voltage: 100-240 V 50-60Hz
  • Output: 5.0V 2.1A

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It is a cheap charger and as usual is is in a envelope without anything else.
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Measurements


  • Power consumption when idle is 0.27 Watt
  • 1A USB output is coed as Samsung
  • 2.1A USB output has unknown coding.
  • The output are in parallel.
  • There is some leds behind the green plastic.
  • Weight: 32.3g
  • Size: 71.2 × 37.7 × 24.6 mm

Dual%20USB%20Charger%201A%20230V%20load%20sweep
The charger can deliver over 3A on the 1A output before it has problems.
Dual%20USB%20Charger%202.1A%20230V%20load%20sweep
And the same on the 2.1A output
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Using them in parallel do not change the current.
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The current is lower at 120VAC and the regulation is not very good above 2.7A
Dual%20USB%20Charger%20230V%20load%20test
The charger can deliver 2.1A for one hour.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.
Temp7150
M1: 41.8°C, HS1: 80.4°C
HS1 is the transformer.
Temp7151
M1: 57.0°C, HS1: 63.1°C
Here HS1 is most likely the rectifier diode transferring heat through the circuit board.
Temp7152
M1: 59.7°C, HS1: 63.7°C
Temp7153
M1: 60.6°C, HS1: 63.0°C
Temp7154
M1: 46.9°C, HS1: 79.1°C
10ohm
At 0.5A the noise is 66mV rms and 723mVpp.
5ohm
At 1A the noise is 89mV rms and 697mVpp.
2ohm
At 2.5A the noise is 127mV rms and 1438mVpp, it is a lot of noise.
Tear down
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Using my vice to apply some pressure just below the green band broke the glue and I could open it.
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The circuit is fairly simple, at the input is a fusible resistor (FR1), the mains switcher is a single chip (DK1203) next to the safety capacitor (CY1) and the opto coupler for feedback. On the low volt side the voltage is regulated with a Zener diode (DZ1) and not the usually reference chip, this means wider tolerance on the output voltage.
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On this side is the bridge rectifier (DB1) and the low volt rectifier diode (D2).
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The USB connectors is on their own circuit board, together with the coding resistors.
There are 4 leds on the other side to light the green band.
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With a slot in the circuit board the distance between mains and low volt side only needs to be 4mm, here it is around 3mm.
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When there is no slot the distance must be above 6mm, here it is around 4mm.
Testing with 2830 volt and 4242 volt between mains and low volt side, did not show any safety problems.
Conclusion
The charger can only sustain maximum output on one port and has lots of noise, strange coding and safety is not that good with the isolation distances on the circuit board being significant below legal requirements.
Notes
Index of all tested USB power supplies/chargers
Read more about how I test USB power supplies/charger
How does a usb charger work?

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

Barkuti
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Joined: 02/19/2014 - 14:46
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Location: Alhama de Murcia, Spain

Thanks. You didn't hint at where did you bought it, yet given the lack of quality guess it is inconsequential.

Concerning some pending reviews, please let me tell you some information is better than no information. Just remembered the Samsung ICR18650-32A you once got from FastTech whose review was never published due to technical mishap, although I would have preferred to at least check the available “up to 4.2V” data. Now that you're also preparing internal resistance graphs for cells I hope other Innocent reviews don't get lost among the pile of pending ones and the stuff you prioritize due to revenue candies.

Thanks again.

Deleting a just published post causes the forum thread answer notification to fail. Thus, if you need to change your just published post, edit it. Thanks.

Please avoid fully quoting lenghty posts, namely with nested quotes. Trim quotes down to the essential. Helps with neatness and legibility. Thanks.

I recommend saying no to Covid vaccine. Listen to your soul. Innocent

HKJ
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Barkuti wrote:

Thanks. You didn’t hint at where did you bought it, yet given the lack of quality guess it is inconsequential.

The reason that info is missing is because I could not find out where I got it from.

Barkuti wrote:

Concerning some pending reviews, please let me tell you some information is better than no information. Just remembered the Samsung ICR18650-32A you once got from FastTech whose review was never published due to technical mishap, although I would have preferred to at least check the available “up to 4.2V” data. Now that you’re also preparing internal resistance graphs for cells I hope other Innocent reviews don’t get lost among the pile of pending ones and the stuff you prioritize due to revenue candies.


Thanks again.

A small percent of stuff/reviews get lost for a couple of different reasons, but it is not due to any revenue. I do not even know if I have got anything for the affiliate links I have posted, I did it because Banggood insist on it, not for revenue. Of course it would be nice if some people use them, so Banggood will send me more stuff (I select most of it, not Banggood).

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

Barkuti
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Last seen: 7 hours 13 min ago
Joined: 02/19/2014 - 14:46
Posts: 5531
Location: Alhama de Murcia, Spain

Nice to hear you select most of the stuff from Banggood, it says a lot; they may have pretty decent or good gadgets and equipment, but they also carry so so stuff.

Thanks for the explanation.

Deleting a just published post causes the forum thread answer notification to fail. Thus, if you need to change your just published post, edit it. Thanks.

Please avoid fully quoting lenghty posts, namely with nested quotes. Trim quotes down to the essential. Helps with neatness and legibility. Thanks.

I recommend saying no to Covid vaccine. Listen to your soul. Innocent