If you like to tinker with your own electronics projects or are a data geek who needs to know how much juice your tablet, smartphone or other USB device really needs to charge via USB, the Smartronix USB Power Meter will provide that info. It can also tell you how much power a USB port can provide. The built in LCD displays the USB port’s precise voltage (between -19.99V and +19.99V) and the exact current flow (up to 1,999mA). The USB Power Meter runs on 2 AA batteries and is available from CyberGuys for $49.95.
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