Connect your iPhone 6 to your Mac for faster charging

▼ I got myself an iPhone 6 last month. Because it has a larger battery than previous iPhones but the iPhone chargers have remained the same since the iPhone 3G days, I was a bit worried about how long it takes to charge the iPhone 6.

iPhones and other devices with a lithium ion or lithium polymer battery first charge to 80% fairly rapidly and then the charging slows down for the final 20%. At some point, And at some point, Apple started to declare the battery 100% charged even though it was still charging. The Battery Doctor app claims to show when the battery is really fully charged. (But beware of all the "optimizing" and advertising in the app. But hey, it's free.)

My old iPhone 5 with its 5.5 Wh (Watt hour) battery charged at a rate of about 1% per minute until the 80% point. On the charger, my new iPhone 6 with its 6.9 Wh battery charges at 14% per 15 minutes until it reaches 80%. But... connected to my late 2013 MacBook Pro, it charges at 11% per 10 minutes. So the iPhone 5 would reach 80% in 80 minutes, the iPhone 6 on the charger in 86 minutes and the iPhone 6 connected to the computer in 73 minutes. So that's almost a 15 minute difference. Then, it takes about another hour to for the battery to be completely full.

All USB ports and chargers provide 5 Volts. Under the original specifications, USB ports can deliver 500 milliamps (mA) or 2.5 Watts. iPhone chargers deliver 1000 mA or 5 W. As of about 2008/2009, Apple computers can deliver the same 1000 mA to Apple devices. USB 3 ports can deliver 900 mA. But it turns out that my one-year-old MacBook Pro will actually deliver no less than 2100 mA (10.5 W) to my iPhone 6, if we can trust the system (click About This Mac under the  menu):

Coincidentally, this is the same amount of power that the iPad charger delivers. (Which you can use safely with the iPhone.) So actually it's a bit disappointing that the iPhone 6 only charges 18% faster with more than twice the power available. However, the iPhone 6+ has a 50% bigger battery than the iPhone 6, so for the iPhone 6+ the difference is very likely much larger.

Permalink - posted 2014-12-16

Apple Watch: Moore's Law need not apply

▼ Jean-Louis Gassée over at Monday Note has an interesting article talking about how cameras used to last for decades back in the analog days, while they're obsolete within a year or two now that they're digital. And how the same thing is about to happen to the watch: an old mechanical watch will keep doing its thing for decades (I'm assuming some upkeep here), but not so much for an Apple Watch:

There’s no carrier subsidy for the AppleWatch. That could be a problem when Moore’s Law makes the $5K high-end model obsolete.

I'm not so sure Moore's Law is going to make the Apple Watch obsolete within just a few years. Moore's Law states that the number of transistors in an integrated circuit (a computer chip) doubles every two years, and perhaps doubles in performance every 18 months. However, a smartwatch isn't limited by the number of transistors or the speed of those transistors, but rather, the battery powering those transistors. And despite the transistors in mobile CPUs getting smaller, they don't seem to be getting that much more power efficient at undemanding tasks.

This is a list of battery capacities for most iPhones, along with the number of hours they'll play audio and the amount of power playing audio thus takes:

• iPhone: 5180 mWh, 24, 216 mW
• iPhone 3G: 4255 mWh, 24, 177 mW
• iPhone 3GS: 4514 mWh, 30, 150 mW
• iPhone 4: 5254 mWh, 40, 131 mW
• iPhone 4S: 5291 mWh, 40, 132 mW
• iPhone 5: 5472 mWh, 40, 137 mW
• iPhone 5S 5966 mWh, 40, 149 mW
• iPhone 6: 6914 mWh, 50, 138 mW

(Source: Wikipedia List of iOS devices.)

Since the iPhone 3GS the power an iPhone uses to play audio has been between 130 and 150 milliwatts. So for an undemanding task like playing audio there has been no improvement to the iPhone in five years. (Caveats apply; I'm looking at the big picture here.)

As such, I'd be very surprised to see new watches released every year that significantly improve on the previous model's technical specifications. I think the Apple Watch is going to be like the Apple TV or Airport Wi-Fi base stations in this regard: significant updates happen rarely, but modest under-the-hood hardware improvements are rolled out once every year or two without fanfare and with little impact to the user experience.

I am going to be very upset when the 2016 model adds GPS, though. If anything, the watch v1.0's Achilles heel is going to be lack of GPS.

Permalink - posted 2014-12-08