USB meter: USB Digital Tester J7-c (Juwei)

Voltage measuring range: 3.30V~30.0V, resolution Precision: 0.01V

Current measuring range: 0.00~5.10A, resolution Precision: 0.01A

Capacity cumulative range:: 0~99999mAh, resolution Precision: 0.001Ah

Power cumulative range: 0~999999mWh, resolution Precision: 0.001Wh

Power metering range: 000.00~150.00W, resolution Precision: 0.01W

Impedance Measuring range: 1~999.9ohm, resolution Precision: 0.1ohm

Temperature Measuring Range: 0~80°C, resolution Precision: 1°C

Maximum Timing: 999Hours 59Minutes 59 Seconds, resolution Precision: 1s

Timer Charging Reminder: Countdown 24 hours, set value arbitrary

USB D+ Voltage Range: 0V~2.999V, resolution Precision: 0.001V

USB D- Voltage Range: 0V~2.999V, resolution Precision: 0.001V

Full Charger Reminder Parameters of Mobile : <2W/0.5Hours

Time to refresh: 500mS/ times

Measurement rate: 0.5 times/s

Alarm Mode: Siren Sound+ Display Hints

Product size: 60mm x 60mm x 11mm

Self-consumable flow: <0.02A

Working temperature: -10~+60?

Working humidity:: 10~80(no doubt)

How does it look

Measurements

Own current consumption is 12mA

Internal resistance is about 0.12ohm including connection resistance.

Remembers Wh and Ah when power is off

Voltage display is within 0.02 volt in the 4.0 to 6.0 volt range.

Current display is within 0.02 ampere in the 0 to 3.0 ampere range with 5 volt supply.

It is possible to enable audible alarms for over current, over voltage, under voltage.

Usb-c has a resistor to trigger power output on dual purpose usb connectors.

USB data works fine.

Meter has a buzzer.

Conclusion

Notes