# Use Fire cord to charge K2 and KK?



## debrajean (Jul 30, 2011)

Can I do that? Thanks


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## fuschiahedgehog (Feb 23, 2010)

yep, any microUSB charger will work.


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## Ann in Arlington (Oct 27, 2008)

I'd be careful about using the Fire's charger on your eInk kindles.  I believe that it provides a higher than recommended voltage.  So you'd possibly risk damaging a device that wasn't designed to take that flavor of electricity.  I'm going to move this question to our Tips, Tricks, and Troubleshooting board where a lot of our techies hang out. . . I'm guessing one of those folks can explain what's what.

You definitely CAN charge the Fire with an eInk charger -- but it won't charge as fast as it would with it's own chord. . . .I've done that myself.  But never had the nerve to go the other way!


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## Morf (Nov 18, 2010)

I'd be very surprised if the Fire's charger provides a higher voltage than the standard USB 5V, if it did then that would bring all sorts of problems.

However, to be sure, if somebody can read the label on the Fire's charger and reply with the details (input and output voltages and currents) I'll give you a better reply.


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## Ann in Arlington (Oct 27, 2008)

Your wish is my command:  here's what the block at the plug end of my Fire charger says:

AC INPUT 100-240V 50-60Hz 0.3A
DC OUTPUT 5V  1.8A

The plug on the Kindle (the removable one) says

same input
DC OUTPUT 4.9V    0.85A

And, just to be thorough, the plug that goes with my phone, a Droid Razr, says

same input
DC OUTPUT 5.1V  750mA  (or, to keep units consistent 0.75A)


My uneducated observation is that it's the double current that might be an issue.


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## Jeff (Oct 28, 2008)

Ann in Arlington said:


> My uneducated observation is that it's the double current that might be an issue.


The amperage is only an indication of the charger's capacity. It won't supply any more power than demanded. Power(Watts) = volts X amps of the device.


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## Morf (Nov 18, 2010)

Ok, the long explanation is over on this thread - http://www.kboards.com/index.php/topic,104767.msg1592861.html#msg1592861.

Short summary - Jeff is entirely correct, there _shouldn't_ be a problem, but however many times I try to convince myself of this, I always err on the side of caution and stick with chargers of 1A or less.

With a rating as high as 1.8A, personally I wouldn't chance it despite being fairly sure there wouldn't be a problem.


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## Ann in Arlington (Oct 27, 2008)

Yeah, that's my feeling, Morf.  It should be fine -- unless it's not.   Maybe I'd risk it if I was desperate.  

I KNOW the Fire charges faster on it's specified charger than when I just plug it into a phone charger I always have downstairs.  OTOH, I also don't worry about leaving it charging over night which a lot of people are very leery of doing.


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## debrajean (Jul 30, 2011)

Wow! You guys rock! Thanks for the info, help and advice. I don't believe I will chance it.  ~sigh~ I will have to share k2 charger with son,  lol.  Deb


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## fuschiahedgehog (Feb 23, 2010)

Of course your mileage may vary but I've never blown a device using a higher-amp charger.  I don't even know where my original Kindle chargers are - I have a few 1A-5V and 2A-5V USB chargers scattered throughout the house that we use to charge all our gizmos.  And we have LOTS of gizmos.


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## Ann in Arlington (Oct 27, 2008)

Here's a whole page of not very expensive replacements you can get:

http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Delectronics&field-keywords=kindle+power+charger

You can get just the cord, just the plug, or both. . .or get sets that also include a power adapter for your car.

There are also probably equivalents available from places like Radio Shack. And, FWIW, many phones use similar charger systems and can be interchanged with the Kindle. I generally just travel with one and use it for both my kindle and my phone. The key is it has to have a micro USB plug at one end. I have chargers staged in a couple of different rooms in my home so that I can charge it wherever I need to.


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## lori_piper (Oct 7, 2010)

FWIW, I use my Fire charger to charge my K3 all the time. I never really thought about it.


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## Morf (Nov 18, 2010)

It's interesting that a couple of people have reported no problems with charging from Fire (or other 1-2A) chargers.

I suppose it's no different from worrying whether your phone or TV will be damaged if you plug it into a 13A wall socket (or 15A in America) when it only needs 0.5 or 1A.

The rating is the maximum limit that the socket can supply, not what it puts out all the time.

So you probably are safe to do it.

You *do* need to be careful of charging something that needs a high current (eg an iPad) from a low current charger, unless you are sure it is suitable - the damage will be to the charger, though, not the iPad.

This is rather like plugging a toaster into your light socket. The damage will not be to the toaster but to your lighting wiring (and fuse).


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## Betsy the Quilter (Oct 27, 2008)

I interchange them all the time.  And I trust Jeff.  He knows stuff. And Morf.  He also knows stuff. 

Betsy


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## Morf (Nov 18, 2010)

Awww, shucks!


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## Betsy the Quilter (Oct 27, 2008)

I, on the other hand, don't really understand amps/volts/watts.  But I did read a biography of Micheal Faraday once.



Betsy


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## Jeff (Oct 28, 2008)

Betsy the Quilter said:


> I, on the other hand, don't really understand amps/volts/watts.


Watts are the work that electricity does. The work produced by a light bulb for example, is light. The higher the wattage the brighter the light. Let's use a light bulb to demonstrate why you can use a charger with higher amperage rating:

In electrical theory, wattage is determined by voltage multiplied by amperage. The typical household wall-socket in the United States offers about 120 volts on a 15 Amp circuit breaker. (The breaker "blows" if you use more than 15 amps.) Since we know that watts are equal to volts times amps, we know that we can plug in anything that uses up to 1,800 watts. We also know, from practical experience, that we can plug in something that doesn't need all those amps such as a lamp with a 40 watt light bulb.

Make any sense?

I changed some terminology and mixed AC with DC theory to make it simple.


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## Betsy the Quilter (Oct 27, 2008)

I knew how to trip a circuit breaker already.    If I think about it hard enough, I'm sure it will sink in.  Just like percentages.  

I do find the story of the competing currents DC vs AC very interesting and compelling.

Betsy


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## Jeff (Oct 28, 2008)

Betsy the Quilter said:


> I do find the story of the competing currents DC vs AC very interesting and compelling.


Leslie and I have that discussion occasionally.


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## Betsy the Quilter (Oct 27, 2008)

Well, that discussion  aside, the lengths Edison was willing to go to to try to keep DC the current of choice are really interesting.

Betsy


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## Tatiana (Aug 20, 2010)

Jeff said:


> Watts are the work that electricity does. The work produced by a light bulb for example, is light. The higher the wattage the brighter the light. Let's use a light bulb to demonstrate why you can use a charger with higher amperage rating:
> 
> In electrical theory, wattage is determined by voltage multiplied by amperage. The typical household wall-socket in the United States offers about 120 volts on a 15 Amp circuit breaker. (The breaker "blows" if you use more than 15 amps.) Since we know that watts are equal to volts times amps, we know that we can plug in anything that uses up to 1,800 watts. We also know, from practical experience, that we can plug in something that doesn't need all those amps such as a lamp with a 40 watt light bulb.
> 
> ...


Jeff,

Where were you when I was struggling to understand this all in physics class?

Your explanation is so much more clear than the book or the instructor! Now I understand it. Thank you!


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## Betsy the Quilter (Oct 27, 2008)

I told you.  Jeff knows stuff...

Betsy


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## Morf (Nov 18, 2010)

The way I was taught how to remember Volts Amps and Watts, which has always made sense to me, is to think of electricity like water in a stream or river.

The amperage, or current, is how much water is flowing down the river.

The voltage is how steep the river is ie how much the water is being pushed.

The wattage is how much work the water can do - think of a waterwheel, for instance.

So, if you have a lot of water flowing down a shallow slope (think the Mississippi, for instance) you can get a lot of work (wattage) from it - high amperage, low voltage.

But you can also get a lot of work from a small amount of water flowing down a steep slope (high voltage, low current) - I guess the Colorado river through the Grand Canyon is an example of this.

High voltage and high current produces a huge amount of work - think about a Tsunami for example.

Your charger is rather like a tap - the water pressure (voltage) is fixed, you can vary the amount of water (current) you want from it, but there's a maximum amount it will let out - this is the rating on the charger.


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