Test/Review of USB meter: Volt Current Voltage Charger Capacity Tester

6 posts / 0 new
Last post
HKJ
HKJ's picture
Offline
Last seen: 2 hours 6 min ago
Joined: 05/24/2011 - 12:23
Posts: 7433
Location: Copenhagen, Denmark
Test/Review of USB meter: Volt Current Voltage Charger Capacity Tester
USB meter: Volt Current Voltage Charger Capacity Tester

DSC_7491

Official specifications:
  • Voltage: 3V-10V(accuracy: 1% )
  • Current: 0-3.3A(accuracy: 0.4% )
  • Display Panel: OLED(letter color: white)
  • Size: 42mm * 19mm * 10mm(1.65'' * 0.75'' * 0.39'')
  • Sampling resistance : 50mOhm
  • Reading: U=Voltage, P=Power, I=Currency,C=Capacity(mAh)

I found this unit on Ebay at a dealer called axeprice



How does it look

DSC_7476
DSC_7477

The usb connector is not mounted straight.

DSC_7494

DSC_7478 DSC_7479

DSC_7481

The small display is a graphic OLED display with very small letters.

DSC_7821

I could just pry the box open.

DSC_7822

This device does not have a current sense resistor, but uses a MAX471 current sense chip (That has a 35mOhm resistor inside).

DSC_7823

DSC_7824

DSC_7825



Measurements

Test

The watt display is not U*I, but slightly above, this may be due to rounding. Also be aware that the voltage is somewhere between Vin and Vout, i.e. the power is neither input or output power, but something inbetween.
The voltage readout works from around 3.5 volt, but current is first correct above 4 volt.
  • Capacity always starts from 0 when power is turned on.
  • Own current consumption is 15mA
  • USB data works fine.
  • Capacity display are zeroed when power is disconnected
  • Internal resistance is about 0.13ohm including connection resistance.
  • Voltage display is within 0.04 volt in the 4.0 to 6.0 volt range.
  • Current display is within 0.01 ampere in the 0 to 3.0 ampere range with 5 volt supply.
  • Text on display is small, numbers are maybe 2mm high.


Temp1343

M1: 43,4°C, M2: 50,1°C, M3: 42,8°C, HS1: 53,2°C
Even with this fairly low internal resistance the device gets warm at 3A.

Temp1344

M1: 56,5°C, M2: 50,9°C, HS1: 67,5°C



Conclusion

Fairly low resistance, good precision, works from 3.5 volt for voltage, but more than 4 volt for current, capacity and power display, but the display is fairly small.
This is a good usb meter when measuring at 5 volt.


Notes

How do I make the test

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

Edited by: sb56637 on 06/25/2015 - 13:46
Woody
Woody's picture
Offline
Last seen: 2 weeks 4 days ago
Joined: 02/20/2012 - 17:08
Posts: 1644
Location: London

Another great review HKJ – many thanks. I don’t think this is available from ebay.co.uk – the seller axeprice on ebay.com won’t ship to the UK.

HKJ
HKJ's picture
Offline
Last seen: 2 hours 6 min ago
Joined: 05/24/2011 - 12:23
Posts: 7433
Location: Copenhagen, Denmark

Woody wrote:
I don't think this is available from ebay.co.uk - the seller axeprice on ebay.com won't ship to the UK.

You might be able to find it at another dealer.

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

WarHawk-AVG
WarHawk-AVG's picture
Offline
Last seen: 1 year 4 months ago
Joined: 01/04/2014 - 06:47
Posts: 5071
Location: H-Town

Nice..thanks!!!

hammerJoe
Offline
Last seen: 1 year 5 months ago
Joined: 02/12/2015 - 19:56
Posts: 150
Location: Canada

Is this a good buy or not?

WarHawk-AVG
WarHawk-AVG's picture
Offline
Last seen: 1 year 4 months ago
Joined: 01/04/2014 - 06:47
Posts: 5071
Location: H-Town
hammerJoe wrote:
Is this a good buy or not?

If HKJ says this

Quote:
Conclusion

Fairly low resistance, good precision, works from 3.5 volt for voltage, but more than 4 volt for current, capacity and power display, but the display is fairly small.
This is a good usb meter when measuring at 5 volt.


You can be guaranteed as long as the seller is reputable…this model of USB Volt Current Voltage Charger Capacity Tester is a good design