Instruct: Classify a given review into positive or negative sentiment.
Query: Design Flaw?

I have used 2 of these. They both have the same problem. It seems that the unit can be over-charged. After charging the unit per the Motorola instructions, the unit worked as advertised. Since it was to be used in my auto, I left it plugged to the DC power to keep it charged. Bad decision! The unit would not connect and I couldn't turn it off to reset it. The only way to turn it off was to let it discharge completely. It would then reset and connect to the cell phone. Motorola told me the unit was defective. Returned the 1st unit to Amazon, and now the replacement has the same problem! Can't return the unit now - had it too long. I just don't charge it for an extended time.