compare the different voltage/mA from wall to car charger. But a charger that causes a phone to freeze? sounds like a crap charger. I never liked buying bundled chargers because they are always crap, unless it was name branded. It would be better to get OEM. I use a charge adapter with open usb port (belkin or jawbone from my headset) and just plug in the cord the phone came with if I think I'll need it, like a long trip. I haven't seen that type of malfunction from a charger other than giving my phone USB settings to choose from. I just back out and it keeps charging. Hope this helps.