A dozen USB chargers in the lab: Apple is very good, but not quite the best

Post by tisme » Sun, Oct 28, 2012, 10:14 AM UTC

kens wrote: post #33

GuiA wrote: post #18

" Since the designers of the Apple charger went to a great deal of effort to build a high quality charger, I conclude they must not consider voltage sag worth worrying about. Or, more interestingly, maybe they built this sag as a feature for some reason. In any case, the chargers lose points on this." I'm not versed in the arcane arts of EE— could anyone give me a basic definition of voltage sag? And would there be a…

Hi, the author here. I'm using voltage sag to describe how the voltage drops as the load increases. (This has nothing to do with the presence of a battery or not.) Chargers normally are designed to output a constant voltage until the charger hits maximum power. But with the iPhone charger, the voltage is 5.2 volts if there's no load, and steadily drops to 4.6 volts as the load increases. If a device is expecting 5 vo…

Post by polyfractal » Sun, Oct 28, 2012, 1:07 PM UTC

Evbn wrote: post #62

w1ntermute wrote: post #60

Earlier quoted context omitted.

The problem isn't for me personally - I don't own any Macs. The issue is other people who have Macs and plug them into wall outlets in public places and cover up other slots. And I've never seen anyone carrying around an extension cable.

Because the cords are ridiculously fat, more than other manufacturers'. They shouldn't block anything, just turn them upside down if needed.

Post by rzimmerman » Sun, Oct 28, 2012, 2:23 PM UTC

kens wrote: post #33

GuiA wrote: post #18

" Since the designers of the Apple charger went to a great deal of effort to build a high quality charger, I conclude they must not consider voltage sag worth worrying about. Or, more interestingly, maybe they built this sag as a feature for some reason. In any case, the chargers lose points on this." I'm not versed in the arcane arts of EE— could anyone give me a basic definition of voltage sag? And would there be a…

Hi, the author here. I'm using voltage sag to describe how the voltage drops as the load increases. (This has nothing to do with the presence of a battery or not.) Chargers normally are designed to output a constant voltage until the charger hits maximum power. But with the iPhone charger, the voltage is 5.2 volts if there's no load, and steadily drops to 4.6 volts as the load increases. If a device is expecting 5 vo…

Post by [deleted] » Sun, Oct 28, 2012, 2:38 PM UTC

kalleboo wrote: post #54

polyfractal wrote: post #51

Very interesting review, I enjoyed the dissection and review of what most people don't even think about (wall chargers). On a non-technical note, Apple chargers should lose simply because of how goddamned large they are. They basically eat two spots on a power strip and are easily knocked out of wall sockets because of their weight.

One thing that always annoys me when Apple products take over the world is how they are limited to American constraints. Sony Ericsson made a brilliant charger that plugged into the wall and you could just stand your phone onto. Apple would never think of that since the American plug standard is too weak to carry the same weight a Schuko can. And now everyone has to copy Apple instead of innovating...

Post by nicholassmith » Sun, Oct 28, 2012, 3:48 PM UTC

Lagged2Death wrote: post #76

nicpottier wrote: post #12

Too bad the Amazon Kindle charger isn't in the mix, it is my favorite just because it is so tiny and relatively high output. Would have liked to see same analysis for it.

I've got 3 USB chargers in the house, including a Kindle charger, and none of them inter-operate at all. Ridiculous.