Everything You Need To Know About Charging Your iPhone, iPad, iPod

Since the birth of Apple portable products, the charging adapters, cables and requirements have changed over the years. When purchasing a charging adapter – or trying to charge an Apple product through a USB port many users have come across issues where their Apple device does not charge. In this post I hope to outline and explain the electronics behind charging your Apple iPod, iPhone or iPad so you can understand exactly what you need to efficiently charge your device.

Chargers:

Source Voltage Current Power
PC USB 5 volts 0.5 amps 2.5 Watts
iPhone Charger 5 volts 1.0 amps 5 Watts
iPad Charger 5.1 volts 2.1 amps 12 watts

In the above table, PC USB means a standard USB port on most computer motherboards. Your motherboard may have some ports with higher power ratings or configurations adapted to charge Apple products. iPhone Charger refers to the mains power adapter that ships with all iPhones up to the iPhone 5S and iPad Charger is the power adapted that ships with all iPads up to 6th-gen. Also note that older generations of the iPad were shipped with 10 watt adapters.

Now to debunk some common myths and questions….

Will they all charge an iPad even when the indicator shows ‘Not Charging’?

Yes. Your PC USB will charge your iPad – but very, very slowly. This is because a PC USB typically only provides 2.5 Watts of power which is less than a quarter of what an iPad power adapter will provide (12 Watts). But the screen of your iPad must be turned off otherwise the 2.5 Watts of power from the USB goes straight to powering the screen and does nothing for your battery.

Similarly, if you use the power adapter bundled with an iPhone to charge your iPad you should notice that charging the battery takes about twice as long. This is because again, the power outputted through a iPhone power adapter is approximately half of that of an iPad adapter.

But they all have 5V output?

Yes they do all have more-or-less 5 volt output. But for those who have studied Physics you’ll know that Watts = Volts x Amps; where voltage is the electrical energy given to each electron and amps (current) is the rate at which the energy is transferred. So in very simple, abstract terms; all the adapters give each electron 5 volts of energy however the iPad adapter pushes these electrons out much faster. Infact it pushes the electrons out twice as fast (2.1 amps compared to 1.0 amps). This is why charging an iPad with an iPhone adapter takes approximately twice as long!

Apple have simply re-configured the iPad adapter in order to charge the battery faster since it has a greater capacity.

Can I use an iPad adapter to charge my iPhone? Is it safe?

Though I cannot guarantee anything since Apple haven’t made a statement answering this query; I’d say yes. The voltage is the same so you are unlikely to burn any components. But since the current is 2x that of what an iPhone expects your phone might heat up a little when you charge it. Other than that, it should charge twice as fast.

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