Apple appears to be addressing long charging times for its mobile device batteries. An Apple patent application for “high voltage charging for a portable device” describes systems for safely charging a portable device using high voltage.
Published by the U.S. Patent and Trademark Office, Apple’s application details techniques for using high voltage to charge a battery. The application states:
Due to the size of these portable devices, the power source for these devices, e.g., an internal battery, is often small and of limited capacity. As a result, the battery of a portable device may have to be frequently charged in order to keep the portable device operational. Depending on the amount of charge an internal battery of a portable device is designed to handle, the charging time for the battery may range from 1-2 hours to over 12 hours. The main reason being the voltage (and consequently the current) used to charge these portable devise is usually less than to close to 5 V, which results in longer charging time. As the demand for higher capacity batteries in portable devices increases, the charging times will get longer.
According to the application, using high voltage may decrease the charging time drastically. This new device (a cable or an adopter) will have the capability of providing voltage of up to 20 V. This new application describes a new technique regarding how mobile device and power supply would communicate to determine then provide the specific voltage that was required by the mobile device in the range of between 5 V and 20 V. This makes it possible to use this charging device with different size mobile devices requiring different voltages.
This new patent further describes a smart way to charge batteries. According to the application:
Based on the identification information, the portable device may determine whether the power supply is potentially a “smart power supply”. A “smart power supply” in this context means a power supply that is able to exchange capability and other information (other than provide power) with the portable device over dedicated data lines and optionally, the power supply is able to provide an output voltage of up to 20V. If the portable device determines that the power supply is not a “smart” power supply, then the power supply operates in its default mode, e.g., output 5V or less.
This new device may gradually increase or descries the voltage. Apple gives this example:
For example, if the battery is 100% depleted or close to 100% depleted, the portable device may initially request the maximum voltage output from the power supply. As the battery begins to charge, the portable device may progressively reduce the output voltage requested from the power supply. For example, when the battery is 80% charged, the portable device may reduce the requested voltage from 20 V to 10 V.
Currently Apple offers ~5 V adapters for its iOS devices. Apple may be planning to free some space in its devices (thinner, lighter and faster devices?) by making battery’s smaller. This approach may mean that Apple will focus on quicker charging times as opposed to longer battery life.
Apple’s high voltage charging for a portable device patent application was first filed for in November, 2013 and credits Fritchman Dan; Terlizzi Jeffrey J.; Sims Nicholas A.; Thompson Paul; Krueger Scott as its inventors.