When looking on Amazon for a car charger I noticed that different items have different amp values, 2.1 and 3.1 being the most frequent. What is the recommended value?

Does it even matter? Is there more to it than the fact that more amps mean faster charging?

5 Answers 5


More amps will not mean faster charging. The iPhone (and any electronic device) will only take as much current as it requires, and no more. The iPhone will take 1A to charge, and an iPad will take 2.1A.

There's no harm in using a charger that is capable of providing more current than a device requires, but there's no benefit either.

Providing less current than the device requires will lead to longer charging times, or no charging at all.

  • 3
    In practice iPhones do charge a little faster with an iPad charger. It seems the charging circuit can pull a bit more current than the standard charger provides.
    – jaberg
    Sep 27, 2013 at 2:56
  • The Apple iPad chargers, according to the Apple Store Genius, have a sensor in them that can detect an iPhone and in that case will only put out 1AMP but if we use another charger not from apple it would charge the Iphone faster and can even deteriorate your battery or burn your Iphone completely
    – Muhammad
    Apr 6, 2018 at 10:20

I disagree with parts of Nathaniel's answer. The normal iphone charger is 5W and just over an amp. Using an iPad charger, either the 10W or newer 12W will absolutely charge your iphone faster. In fact, almost twice as fast. However there's some speculation that it may shorten the battery's lifespan. I've had no problems using an iPad charger on my 5S and it's charged in no time. So, you take a chance I guess but yes, the 2.1 amp ipad charger will cut charging time down considerably.

  • 4
    This looks a bit confused. The question is asking about amperage, not watts. 2.1 amps (2.1A) is not the same thing as 2.1 watts (2.1W). Also, unsourced speculation is unlikely to be helpful. In addition, regarding "That answer is false" - this is not a discussion forum, you should not use answers to comment on other answers. Just stick to answering the original question.
    – D.W.
    Jul 26, 2014 at 0:08
  • I hope you do realize that more amps (I) means more watts (P) since P=I*U and U is constant in this case (5V).
    – bviktor
    Sep 13, 2016 at 21:57

I'm using a 2.1 Amp charger for my iPhone 5 and it's charging extremely fast from 0 to 30 in just 15 minutes !


Car chargers typically mis-represent the amperage they supply. I have several, most of which indicate 2.1A, and they re-charge my iPad 4 and iPhone 6 at different rates. Price is no guarantee, but in my experience, the correlation holds: the brand-name Griffin PowerJolt is my most expensive, and fastest car charger.



The I-pad chargers supply current at 12V and not 5V thus it will not charge the phone faster but will damage the charging port.*

*This is completely wrong. Current is measured in amps (I) not volts (V). Where wattage is W: W = IxV.

I do not know if higher wattages will damage your phone, but I do know when I accidentally hook-up my iPhone to my iPad charger, it heats up considerably.... I'd be very concert that if left for an extended period this would overheat and permanently damage my phone!

  • 2
    Current is measured in Amps not Volts to kick off. However iPhone and iPad chargers both supply at 5V. iPhone model provides max ~1A and iPad ~2A The charging circuit in the device will only draw up to it's design limit.
    – Kevin
    Feb 27, 2015 at 12:11

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