Droid and iPhone dislike cheap USB chargers unless...

Thursday, February 25. 2010

Droid and iPhone dislike cheap USB chargers unless...

... you have an electronic hacker in your neighborhood. I bought the cheap Chinese solar USB charger revolt “4 Seasons” and wanted to use it to charge my Motorola Milestone/Droid or other devices while travelling by train or bike or during a hike. Unfortunately, it only provided power to “dumb” devices like not-so-smart phones or USB On-The-Go hard disks. When I connected it to my Milestone, the phone didn’t jump to the charging state. WTF? It turned out that modern smartphones like Milestone/Droid or iPhone rely on a properly implemented USB standard, what means that it’s not enough that the two outermost USB pins carry the needed voltage, but the inner pins must also provide a minimal “data voltage”. The problem is described here, and here is a DIY solution.

Thanks go to my work mate Wolfi for hacking the solar charger successfully.

Posted by Stephan Paukner in Information Technology at 20:32 | Comments (5) | Trackbacks (0)

Defined tags for this entry: diy, electronics, phone

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Hi Stephan, I have exactly the same problem, though with my lg arena :/ I bought the revolt 4 seasons charger but when I connect it to my phone it doesnt start charging..I dont know anything about electronics but I definitely want to try and make that damn charger work

so I was wondering whether you/ your friend who hacked the charger could tell me how to connect the inner pins to the outer ones (or maybe show a picture of how the inside looks now??). I opened the charger but the circuit board is glued down plus theres this black thing really close to the pins, so I am rather hesitant to ‘just try’ something. Hopefully you could help me out! Thanks for your time

Grts, Claudia

#1 Claudia on 2010-07-02 17:01 (Reply)

Hi! Did you look at the DIY solution in the last link? There’s a wiring diagram that shows the concept. HTH. Btw, I’m going to sell my modded charger, as I use a stronger standalone battery now, without solar panels.

#1.1 Stephan on 2010-07-04 09:20 (Reply)

Hi, yes I did but I didnt really understand it :/ but I also found another site (http://wiki.siftah.com/IPhone_3G_3GS_USB_Cigarette_Lighter_Socket_Charger) and there only 2 resistors are used, so then I was even more confused..how many did you use and do you know how many ohm they are maybe?? Its just really annoying cuz its the second solar charger that I bought and they both dont work with my phone

So I think Ill just try something even if it will break it, otherwise it will be a waste of money anyhow.

#2 Claudia on 2010-07-05 17:29 (Reply)

can you renew the link pls

#3 Torsten on 2011-11-06 12:44 (Reply)

Well, as this is the first link that shows up with search criteria “homemade solar charger for motorola droid 3” on Google, I thought it may be helpful to post a solution. The problem is that effectively, most cheap USB chargers including solar chargers only route DC cables (meaning, electrical supply wires) through USB connectors, and not the data cables. The thing is, the USB Battery Charging Specification of 2007 defines that a charging port must have the data wires shorted. If not, the phone does not recognize the charger. Hence, to make one of these chargers to work, the micro USB end that connects to the phone must have the four cables arriving to it (V+, D+, D-, V-), and while V+ and V- should be connected to positive and negative of the charger, D+ and D- must be shorted, (meaning tied together). The micro USB end from the stock cable that comes with the charger is somewhat easy to replace. Grab any old data cable with micro USB end, cut it, strip the wires carefully from the micro USB port side (the wires are pretty thin), and then connect grey (GND) and red (V+) wires from micro USB end to black (GND) and red (V+) wires from charger. Then, the remaining two wires, green and white, should be shorted, e.g. stripped and tied together. That would be all, and the charger should work flawlessly. For a nice finish solder all unions betweem wires, isolate them with tape and use a thermal cover to finish the new cable. Tested on several phones (Nokia E5, Samsung Galaxy Y Pro, Samsung Galaxy SII, Motorola Milestone 3). I hope this helps anyone stuck with a charger that doesn’t work! Best, Sebastián

#4 Sebastian on 2013-02-12 00:44 (Reply)

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