Just by inserting it, I examined it with "USB simple voltage / current checker" which understands charging speed from voltage & current of USB connection
When you purchase a smartphone or tablet, you get an adapter for charging and a USB cable as accessories, but the performance is not all the same. By simply connecting between the cable and the device, it is easy to measure the current and voltage to check the performance of the USB cable and adapter on hand "USB simple voltage / current checker"is. Since there are really a lot of USB devices in the editorial department, I actually measured to see their performance.
USB simple voltage / current checker (3.4 V to 8.0 V, 0 A to 3 A) [RT-USBVA 2] »Limited company Route-R personal computer · peripheral equipment import / wholesale, import substitution, OEM Please leave it to Earle (Route-R).
The way the voltage and current are displayed during measurement with "USB simple voltage / current checker" can be seen from the following movie.
The state under measurement with "USB simple voltage / current checker" looks something like this - YouTube
Exterior of USB simple voltage / current checker (RT-USBVA 2) is like this.
There are instructions and a main body inside.
Just connecting the USB power supply to the device will display the voltage (3.5 to 8.0 V) and current (0 to 3.0 A) with the LED. Measurement error is plus or minus 1%.
The left end is the USB terminal
The right side is a terminal insertion port. Measurement starts immediately by inserting it between the adapter and the USB cable, and the bolt and ampere display automatically switches alternately.
The weight is 15 g, an impression much lighter than general USB memory.
In order to use it immediately, I gathered various devices to charge via USB that was in office.
◆ iOS device
First of all lightning cableApple 5W USB Power AdapterLet's try using. The measurement results are as follows.
IPhone 5: Current 0.72 A, Voltage 5.08 V
IPhone 5s: Current 0.99 A, voltage 5.06 V
Followed by a large outputApple 12W USB power adapterLet's measure the iPhone's current difference and iPad kind.
IPhone 5: Current 0.85 A, Voltage 5.06 V
IPhone 5s: Current 1.00 A, voltage 5.06 V
IPad mini: Current 0.83 A, Voltage 4.91 V
IPad Air: Current 2.06 A, voltage 5.01 V
IPad 4 th generation: current 2.05 A, voltage 5.01 V
First iPad: Current 1.28 A, voltage 5.04 V
IPad 3 rd Generation: Current 1.75 A, voltage 5.04 V
Even if you use a 12 W adapter, the current of the iPhone does not change, so it seems that you can not raise the charging speed. However, the output was not weak, and the iPad Air recorded a current of 2.06 A.
◆ Smart phones · tablets · data terminals
Nexus 4: Current 0.88 A, Voltage 5.16 V
Nexus 4 (non-contact pad): current 0.82 A, voltage 5.15 V
Nexus 7(Dedicated adapter): current 1.11 A, voltage 5.09 V
Nexus 7 (dedicated adapter + contactless pad): current 1.13 A, voltage 5.11 V
GALAXY S4: Current 0.81 A, voltage 5.14 V
Xperia Z1: Current 0.41 A, voltage 5.02 V
Xperia Z1 (charging stand): current 0.26 A, voltage 5.02 V
Wi-Fi STATION L-02F: Current 0.12 A, voltage 4.94 V
Wi-Fi WALKER LTE HWD 11: Current 0.08 A, voltage 4.96 V
Wi-Fi WALKER WiMAX 2 + HWD 14: Current 0.07 A, voltage 4.96 V
Since charging was in MAX state in both cases, the current of Xperia and data terminal was considerably low. Will the current decrease with Nexus contactless pad? Although I was thinking, since almost the same result was obtained as a direct connection, it seems to be safe to use it in the future.
Kindle Fire HDX: Current 1.28 A, voltage 5.09 V
Kindle Fire HD 7: Current 1.50 A, voltage 5.08 V
Kindle Fire: Current 1.43 A, voltage 5.08 V
The following two Kindle measure with the battery empty.
Kindle Touch: Current 0.07 A, voltage 5.08 V
Kindle Paperwhite: Current 0.34 A, voltage 5.09 V
Kobo Glo: Current 0.48 A, voltage 5.08 V
Since it turned out that little current was flowing in Kindle Touch, it was improved to 0.41 A and 5.11 V by changing the cable. It seems that the cable was weakened, but it also helped to locate the fault location.
◆ Extra edition
Girocam: Current 0.81 A, voltage 5.10 V
Although the equipment used this time is verified with the remaining battery level being 100%, there is current consumption on the device side as well, so it can not be said that "charging current" can be said unconditionally, but the current is large for each cable and adapter I realized that it was different. By setting the power consumption of each device to certain conditions such as putting it in the flight mode, it is also possible to obtain more accurate measurement results. If you feel "a little charge speed ... ...", you can improve the charging speed simply by changing the combination of cables and adapters on hand or you can create the fastest combination.
In addition, the selling price of "USB simple voltage / current checker" at Amazon is 950 yen including tax at the time of article writing.
Amazon.co.jp: Root Ear USB Simple Voltage / Current Checker Straight Type (3.4 V to 8.0 V, 0 A to 3 A) RT-USB VA 2: Home Appliances / Camera