Pirl Charger 4x2.7A usb

DSC_6646

Official specifications: This is a pre-release model, I got it from the developer (It is supposed to launch on Kickstarter in April 2018).
Being a prerelease model there was no box or accessories, I do not know if any will be included on Kickstarter.

DSC_6647

The top and bottom is aluminium.

DSC_6648

DSC_6650

The box is built from layers of circuit board.

DSC_6649

DSC_6651

DSC_6645

There is an indicator for each usb output, it is lit when it is delivering power and red if there is a fault.
The display shows total output power and there is a button beside it to adjust brightness of the display: off, low, medium, high.



Measurements

Load%20sweep%207V%20%231

Rating is 2.7A and overload protection trips at 2.8A, this is fine. The above curve is done at minimum input voltage.

Load%20sweep%2011.6V%20%231

Minimum voltage in a car.
The output voltage will increase with load, but it hits maximum increase at around 0.8A, then dropping output voltage at higher current is mostly due to connection and cable resistance.

Load%20sweep%2014.6V%20%231

Maximum voltage in a car.

Load%20sweep%2017V%20%231

Maximum rated input voltage.
There is not much different on the output with varying input voltage.

Voltage%20sweep%202.7A%20%231

Load%20sweep%2011.6V

All outputs with maximum input voltage.

Voltage%20sweep%200.5A%20%231%20input%20current

Input current will depend on input voltage, at this low load it can maintain output voltage at slightly lower than rated minimum voltage.

Voltage%20sweep%200.5A%20%231

Voltage%20sweep%202.7A%20%231%20input%20current

At full power it need 7V input to maintain output voltage.

Load%20sweep%2017V

Testing with all outputs at the same time.
Efficiency is slightly better than my curve shows, I have some looses in the cables and connectors.

Load%20test%2010.8A

Running 1 hour at 10.8A, display on charger shows 51 Watt (It was more like 53 Watt).
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.

Temp5115

M1: 60,5C, HS1: 75,9C
With an aluminium top the temperature is fairly uniform, notice the input cable it is hot due to power loss in it and the connector.

Temp5116

HS1: 83,4C
At full power the bottom gets very hot (In real usage this power level will seldom or never be reached).

Temp5119

M1: 99,4C, M2: 98,1C, M3: 83,9C, HS1: 100,7C
After the above boring pictures, I did a test more with it open. 100C may sound bad, but the chips are rated for 150C inside, i.e. it is not too hot for the chips.

10ohm

Noise is 11mV rms and 83mVpp

5ohm

Noise is 10mV rms and 107mVpp

2ohm

Noise is 3mV rms and 57mVpp

2ohm%2B8A

Noise is 3mV rms and 58mVpp

2ohm7V
Noise is 2mV rms and 58mVpp

2ohm17V

Noise is 8mV rms and 94mVpp, all tests show very low noise.



Tear down

DSC_6658

Four screws and it was open.

DSC_6652

The top has light pipes for all the indicators.

DSC_6653

At the input is a high current power mos (RS1E200) and a sense resistor (R010) with a current sense chip (Probably ZXCT1022). For showing power is a microprocessor (ATTINY84A) with its own power supply chip (Maybe TPS715).
Each channel has a buck converter (AP65453) and a usb charge controller chip (TPS2549) that handles increasing voltage, protocol and overcurrent. The is also a small chip, I believe it is a voltage monitor (Maybe X6101 series). There is both a white and a red led for each channel (No multicolor led).

DSC_6654

DSC_6655 DSC_6657

DSC_6656


Sorry, no pictures from the bottom, the circuit board and the bottom aluminium plate would not easily part.



Conclusion

This is a very powerful usb charger, has auto coding, very low noise and individual port protection. The high temperature at full load is not really an issue, no standard usb devices will get it that hot.
I like a display showing output current or in this case output power (The processor must be doing some math with the sense resistor on the input).
The question is where to use it? In the car with a cable to the car battery, in the house with a external mains power supply (Sadly it cannot be used with a typical laptop supply).

I will rate it as a good usb charger.



Notes

The charger was supplied by pirlcharger for review.

Index of all tested USB power supplies/chargers
Read more about how I test USB power supplies/charger