Thursday, January 16, 2014
PortaPow USB Power Monitor / Multimeter / DC Ammeter
This multi-meter plugs directly into any USB socket and allows you to connect any USB cable into it for charging or data transfer. It displays on screen the voltage and current which is being output, acting as both a volt and amp meter.
Flexible cable means you can turn the LCD screen to face you - unlike 'all in one' designs it won't be fixed facing the floor/wall regardless of how the USB socket is oriented.
The meter is useful for solar panels with USB outputs, since it will then allow you to position the panel to maximize the energy it outputs, see what factors affect the panel's performance, and also to see when the output is too low to be worth using the solar panel.
It is also allows you to compare the power of different USB sockets and study the quirks of USB charging. It has an upper limit of 3A.
Note that USB sockets will only output as much power as is demanded by the device you are charging, this is the figure the monitor will show. The monitor will not show the maximum possible power output from the USB socket.
Updated 7th Jan 2014 - Now with improved build quality and even lower resistance for more accurate results