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Multi-USB charger that works with Kindle or iPad
February 6, 2011 1:06 PM   Subscribe

I have a tangle of USB chargers at my nightstand for the devices there: a Kindle, an iPad, an iPhone and a Nintendo DS. All of them charge over USB. I want some thing that is nicer looking that uses just one power plug and comes out into 4 or more USB jacks. These exist, and I've tried a few, and none of them have worked with the Kindle or with the iPad (but are fine with the DS and iPhone.) Is there a multi-USB power charger that for sure works with Kindles and iPads?
posted by neustile to Computers & Internet (3 answers total) 5 users marked this as a favorite
 
You need to look at their power rating. Most show they only supply 0.5A which is not enough juice to charge the iPad. I'm surprised that you're not seeing that as enough to work with the Kindle but perhaps it has a higher requirement than I thought.

You just need to look at the fine print. I've found car adapters that provided 2A for $40 and for $7 - it seems completely unpredictable.
posted by phearlez at 2:54 PM on February 6, 2011


First off, the simplest device that can give you four USB ports is a powered 4 port USB hub. You can get these on eBay for just a few dollars if you order them straight from China. It's worth the wait.

Now, for each device:

Kindle:

Assuming you have a Kindle 1, the USB port is trickle-charge only (meaning, it charges but TAKES FOREVER). But there is an adapter you can buy that will take the USB power from your 4 port hub and also quickly charge your Kindle. You can also DIY.

iPad:
Unfortunately, Apple doesn't have the same charging spec as everyone else. You can get your iPad to charge by soldering in a resistor network as specified by LadyAda here: http://www.ladyada.net/make/mintyboost/icharge.html. I have heard that the "USB Sync Charger" cables for sale on eBay have the appropriate resistor network built in.

iPhone:
Same is true, you'll get faster charging if you have a cable with the appropriate resistor network, although it will charge slowly on normal USB ports.

DS is decent about things.
posted by fake at 2:58 PM on February 6, 2011


phearlez, it's not just that the power is available - a powered USB hub, for example, can supply 10W if the power adapter is 2A (not unusual), but the iPad expects to see certain resistances across d+ and d- on the USB cable to initiate a charge at the fast charge rate.
posted by fake at 2:59 PM on February 6, 2011


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