iPhone car-charger compatibility

Can I use the car charger I got for my iPhone 4 with my iPhone 7?

The label says 400mA 1A, with maybe a superscript tilde (~) between the two figures. (It’s teensy type, so almost impossible to read.)

Thank you,

David

Yes, you can use any power supply you wanted as long as it’s the proper USB provided 12/5 V that is typical of virtually every charger. However, if the supplied amperage is insufficient, the iPhone will happily tell you that It will not charge; but even that is a lie: it will still trickle charge despite the warning. You just won’t be happy with how long it takes to top it off. Just try it and see what you think.

Thanks for the info – I just wanted to make sure the phone wouldn’t be harmed by it.

David

IIRC “conventional” USB charges over a 5V connection. If your adapter supplies up to 1 Amp that corresponds to 5W charging. That’s the same spec as for the charger Apple ships along with the iPhone 7 so you should be just fine. Don’t be surprised if it gets a bit warm though. And @frederico is right, even if there’s not sufficient current coming in, it will still charge albeit more slowly of course.