Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great idea, but disappointing

I gave this two stars because I am hoping my experience is due to a faulty device that is not representative of all produced.I got it for my Samsung Infuse (don't forget to buy the proper tip separately - it won't work otherwise). It sticks out and is difficult to pocket and awkward to hold while charging; but it does provide some juice to finish a task.Mine keeps shutting off before even partially charging my phone. To get it to come back on, I have to remove the bottom case & batteries & reassemble it. I suspect there is not enough tension on the battery holder to maintain proper electrical contact.I have tried it with 2 different sets of batteries and cleaned the contacts with a pencil eraser with the same unacceptable results.I'll keep it because it is small and portable and may help in a pinch. However, I'll carry my larger iGo Charge Anywhere for a reliable phone back-up battery.