VVolts / voltage
What drives current to flow
Think of it as electrical push. “48V” in a report is a voltage value.
A FIRST LOOK AT THE REPORTS
Your first steps
through a measurement report.
You do not need an electrical background.
Start with what was tested and what the numbers mean.
Charging a phone or connecting a laptop: we use our published reports as examples to help you understand the cables you use every day.
01 / THREE UNITS
Start with these three units.
V, A and W each describe something different.
AAmperes / current
How much electric current is flowing
Current describes the rate of electric charge flow. “5A” may be a test setting or an actual measured value.
WWatts / power
The rate of energy transfer
Power describes how quickly energy is transferred. For these DC measurements, it is calculated as V × A.
Wattage alone does not determine a phone’s charging speed.
Charger, cable and device support matter, as do factors such as battery level and temperature.
Does a “240W cable” send 240W into a phone?
Power is supplied under conditions the device supports. With USB PD, the charger and receiving device negotiate voltage and current. A cable rated for “up to 240W” describes its upper supported power capability, not power that always flows.
Charging capability is also separate from data-transfer and video-output support. Even with the same USB-C shape, check the specifications for your intended use.
02 / SETTING AND MEASUREMENT
“240W” and “236.315W.”
Why are they different?
Take our Reference Cable A example. The two numbers have different meanings.
Test setpoint
48V × 5A = 240W
This is the combination of voltage and current specified for the test. It is not a measurement showing that 240W was received.
Medians of measured values
47.263V × 5.000A = 236.315W
These values were measured during a 120-second constant-current hold. Beyond the cable, connectors and recording instrument, a test device receives power in place of a phone or PC and reads the values.
Power source
Sends powerCable & connectors
Carry powerCommunication recorder
Records charging negotiationsReceiving test device
Stands in for a phone or PC
Sends powerCable & connectors
Carry powerCommunication recorder
Records charging negotiationsReceiving test device
Stands in for a phone or PC
Measured values reflect the whole power path, including source behavior, cable, connectors and instruments. This difference alone cannot tell us how many watts were lost in the cable.
Example source: Reference Cable A: English report ↗ (measured 17 October 2026; anonymized public edition dated 20 October). The median is the middle value after sorting measurements. Voltage, current and power shown here are their respective medians.
03 / WHERE TO START
Before reading every table,
follow this order.
What was connected and measured?
Check cable name, length, specimen count and the power source used. Our examples connect a receiving test device in place of a phone or laptop. Adjusting the current it draws lets us examine different charging conditions.
Which conditions were tested?
Look at voltage, current, hold time and AC input. “100Vac / 230Vac” describes the AC supplied to the power source; it does not mean 100V or 230V was fed directly through the USB-C cable.
How did measurements compare with settings?
Compare setpoints with measurements. A loaded hold draws a high current for a set time. A current round-trip sweep gradually increases the current, then decreases it.
What was actually established?
Read about interruptions, retests and untested areas as well as results. A “120-second hold” records that duration and condition; it does not mean hours-long operation or product temperatures were tested.
04 / UNDERSTANDING PASS
PASS means
“within these criteria.”
“29 / 29 PASS” means all 29 planned cases met the criteria stated in that report.
29 cases is not 29 cables
It does not mean 29 cable specimens were measured. The DAISO example, for instance, applies 29 cases with different voltages and loads to one cable.
Read how the tests were completed
For the Framework 2m cable, the final case was retested after a capture-instrument stall. Successful records were assembled across two runs, distinct from completing all 29 cases continuously in one run.
PASS is not a guarantee for every use or every product.
The examples evaluate individual specimens under recorded conditions. They are not USB-IF certification, data-speed, long-term durability or product-temperature test results.
Examples: DAISO measurement example ／ Framework 2m measurement example
05 / READING A COMPARISON
When comparing,
read numbers with conditions.
Voltage droop describes how much the voltage falls when more current is drawn.
For these cable comparisons, the reference voltage is derived from light-load readings before and after the loaded test, then compared with the loaded voltage. It is not simply subtracted from the 48V setpoint.
What does “about 207mV greater than the reference” mean?
A millivolt (mV) is one thousandth of a volt. About 207mV is about 0.207V. At 5A, the DAISO example recorded approximately 207–210mV more voltage droop than the Reference A comparison record.
This is a difference observed in the recorded power paths. It includes effects from the source, connectors, instruments and measurements made at different times. It cannot directly establish isolated cable resistance or whether a product is good or bad.
Before comparing, check cable length, source, current, measurement time and connection conditions. The Framework example is 2m; Reference Cable A is 1m, so length differs too.
A comparison reference is a record for use on the same bench, not a calibrated standard. For the detailed conditions, see DAISO English report ↗ under “Loaded holds and reference comparison.”
06 / QUICK REFERENCE
A quick guide to terms you will meet.
- SRC (source)
- The side that supplies power: the charger or power supply in these examples.
- Receiving test device
(electronic load) - A device that receives and consumes power instead of a phone or PC. Adjusting the current it draws allows different test conditions. “Load” means the power-consuming side.
- Communication recorder
(analyzer) - An instrument that records exchanges between a charger and receiving device, such as the voltage and current to use. In these examples, it is connected in the power path.
- PDO
- Information a source advertises to a device about the voltages, currents and other power conditions it can supply.
- Fixed / PPS / AVS
- Types of power delivery. Fixed uses set voltage levels; PPS and AVS allow voltage adjustment within supported ranges. The modes tested differ by report.
- EPR
- Extended Power Range in USB PD, supporting power up to 240W. The device, source and cable must all support the required operation.
- Median / minimum / maximum
- The median is the middle value after sorting. Minimum and maximum are the smallest and largest recorded values. For an even number of samples, the median is the average of the middle two.
- Case / run / n=1
- A case is one test item; a run is one execution record. n=1 means one specimen was tested, distinct from the number of cases or measurement points.
NOW, OPEN A REPORT
Start with the first page.
Read the specimen, conditions and result summary. Then follow any number that interests you into the tables and figures.
This guide explains how to read GauGau’s published measurement records. For information about the USB PD standard, see USB-IF’s official introduction (English) ↗ for further information.