External Battery Charger for ASUS Transformer Prime (Solved)Tips

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  1. HiDef

    HiDef Active Member

    So I've been trying to figure out how to charge my Transformer Prime from an external battery charger when I'm not near AC, but was having a terrible time making it work. But I solved it.

    First - realize your Transformer Prime requires a minimum of 12 volts to charge, and MOST of the external chargers are 5v only. I purchased the Anker Astro3 10000 mAh charger. It has both 5v AND 9v/12v outputs. Other chargers might work too, but make sure one of the outputs is a minimum of 12v/2A.

    Second - there is NO connector in the box that fits the proprietary power/data connector for the Transformer Prime. But with the purchase of a Female-to-Female USB connector (I bought mine at Fry's, but Amazon also has them) you can make it work.

    Connecting it up - It uses a few of the connectors that come in the box... To make it work: a) you plug the included 12v cable into the Astro 3, then b) you plug in one of the included power size adapters into the 12 volt cable (you'll figure out which one), then c) you plug in the included power-to-USB cable into the power size adapter, then d) you plug in the female-to-female USB connector that you purchased, then e) you plug in your original USB-to-Transformer Prime cable.

    Then voila - done! It sounds complicated, but it's not really, and once you set it up you don't need to take it apart again.

    The second benefit of this charger is that you can simultaneously charge your phone, in my case an HTC LTEvo, but it can be essentially any phone including an iPhone. My Transformer Prime and my phone are both charging nicely as we speak....

    entiel and Beards like this.
  2. Jenniferlg

    Jenniferlg Member

    Hi HiDef!

    I don't mean to be a smartass & I do not know all the step-downs, etc., but I just use a Radio Shack splitter that gives me a cigarette lighter & a 3-prong plug (this is all working in the US anyway). I actually use an additional Radio Shack splitter to divide the new cig. lighter into 2 so I can, in total, charge my Garmin GPS & Atrix phone via the cig lighters & my Prime with an additional, regular Asus power plug. It seems to work fine, though certainly a bit Frankenstein-ish! I might have all that plugged in, my phone as a mobile hotspot, streaming a Google hangout on my Prime (docked, suited & sitting up facing me on the passenger seat) and my phone also streaming music (online playlist from 8Tracks if I really want to guzzle some data!). My phone will bluetooth in a call & I admit, I feel pretty high-tech & it's awesome! All in a cute but not high-end car & my over 200 yo farmhouse, ha, ha! I deal with a lot of health issues & now estate stuff, so I try to make each moment good.
  3. crowly100

    crowly100 New Member

    Hi Def,
    I have the transformer as well why can't you take the original cable from the transformer plug and plug it directly into the battery itself? Why do you have to do all the conversions?
  4. HiDef

    HiDef Active Member

    Because the only way to get 12v out of the Astro 3 is to use a more traditional power cable (kinda looks like a banana plug, but not quite). So then you have to go through the conversions I described. Unfortunately you can't get 12v out of the USB port on the Astro 3.
  5. Jenniferlg

    Jenniferlg Member

    Huh, well, that's interesting, HiDef. I'm sorry, I didn't understand your OP well enough & what you were trying to do. I just thought you meant when you don't have it plugged into the wall, how can you charge it & for me, when I'm not within a building I'm in a car, so that was my solution - to what was never your situation! :p I also always have mine in it's rugged little minisuit & docked, so the battery charge I usually get from an overnight plug-in is really enough to get me through the day, though I do use it heavily. If you were without power & needed a really long charge avail., camping, power outage, don't use the keyboard, etc., you were addressing how a person could fill those needs, sorry.
  6. Beards

    Beards Well-Known Member

    Always on the lookout for additional charging methods.
    Just placed my order for one.

    I have left you a Thank You. :)
  7. Niloc215

    Niloc215 New Member

    Can someone please submit a link to the cable you used? I'm going on a big trip next month and need this to work, so I don't want to waste time getting the wrong cable.

    So far, every F to F cable I see on Amazon has an image of a M to M product or goes from USB to Micro or Mini USB. I can't find this product and I'm leaving in less than a month.

    Any help would be appreciated. Thank you.
  8. wally44

    wally44 New Member

    A got an Anker Astro3 charger and hooked it up to my Transformer Prime as you stated. I had to get a USB gender changer to get it to connect. However, when I hook it up to the charger (using the 12v output), the transformer prime does not see an charger and there no charging action. Has something changed? Why wouldn't this work?

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