I have a Jaybird Freedom bluetooth earphone which charges via a USB cable. I am wondering if I could plug it into the power adapter of my iPad 2 or iPhone 4S AC charger when I travel, since I do not have my PC with me. I checked with the Jaybird earphone manufacturer, and they said that they do not recommend plugging it in to any AC adapter unless it matches the charging specs for the Jaybird earphone, as it may damage the battery. The specs are: AC Power: DC 5A 100mA. My question is, is it safe for me to use my iPhone 4 or iPad 2 AC adapter to charge this earphone?