Something better than car adapter Pass Through....... Get a Portable Power Supply...... There are various brands...... I use a Kensington bought at Best Buy....... Holds power for about 5 days...... Hooks up to Pass Through, cell phones, Ipods and computers...... So I can put it in my pocket and use my Pass Through any where and at anytime...... It tells you how much power is left...... Charges on AC or USB...... Really great.......