i just got my Protek 40 and have only used it a handful of times but I like it so far. My previous power supply was a Astron 50a which weighed 50lbs so I never took it anywhere.. I have been charging my cheap turnigy batteries at 5c, they have been charging in around 20 minutes with my Hyperion Duo 3.. so far I like it and its handy being able to charge your phone..