Due to different USB standards, it can be difficult to know what wattage is being delivered by different USB ports. PC USB ports generally output less than wall chargers, for example. The Practical Meter is a pass-through device that plugs into the USB port to monitor how many watts your device is receiving. Based on this information, it shows bars representing the charging time.
There are five bars displayed on the device, each representing one watt of power. So while it won't tell you exactly how long the charge will take, it will give you a rough idea based on the watts being received.
As an example, a port delivering 5 W of power, which is the maximum wattage of most smartphone chargers, will see all five bars light up, indicating a charge time of around 1.5 to two hours. If the port is outputting just one watt, then only one bar will be lit, indicating a charge time of around eight hours.
To go along with the monitoring device, the company is also offering a 3-in-1 cable that features mini and micro USB connectors, and a 30-pin Apple dock connector. It does not feature a lightning connector, so iPhone 5 owners will need an adapter. The creators claim that the cable includes built-in circuits that optimize charging speeds.
David Toledo, the creator of the Practical Meter and its cable, is seeking funding for his idea on Kickstarter. The project started with a modest US$9,999 goal, and it has blown past that quickly. Backers who want to receive both the Practical Meter and optimized cable will need to pledge $19. Buyers only looking for the cable can purchase one for $7.
The Practical Meter measures 44 mm x 19 mm, weighs 8.5 g and consumes less than one tenth of a watt. The Kickstarter video pitch detailing the device can be viewed below.