Thanks for the information. Alas, I don't have a USB cable that stretches from my office to my car. But I'll try other 2.1 chargers. Anything not to have my iPhone discharge while plugged in.
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Just to be clear, the charger i needed was for my car. The 2.1 amp works great. Charges from 10% to almost full in a 30 minute drive. Prior to getting this one, i was having the issue of discharging while plugged in. No problems what so ever now. Have not had any problem using my charger in the house that came with the phone, or the one that came with my iPhone 3. As long as the cord is okay, I've had no problems.
I ordered the charger through Amazon. Skiva PowerFlow 2.1Amp / 10Watt (Fast) Car Charger for iPhone 4S 4 3GS, iPad 2, iPhone, iPad, & iPod - $25