Archive for June 15th, 2009
I have a Virgin Mobile Kyocera Marbl phone, for reasons discussed there. It’s sufficiently nonstandard that the “fits most phones” headsets and chargers don’t. In particular, I have yet to see a charger with the proper adapter dingus for this phone.
Fortunately, the charger is rated at 5 V @ 350 mA… that’s easy enough.
Cut the charger’s cable in the middle, more or less, and install Anderson Powerpole connectors. The standard color code for 5 V is white / black; don’t use red / black for fear you’ll eventually plug it into a 12 V source and toast the phone.
The charger wires are most likely a far smaller gauge than the 15 A (!) connector pins prefer, so strip the conductors twice as long, double the ‘em over and perhaps add a short length of multistrand hookup wire to fill out the barrel before you crimp it.
Check the polarity before you poke the pins in the housings: you want the +5 V pin in the white housing!
I aligned the housings to match the ARES / RACES standard, as described there, as that’s what I’ve done with all my other Powerpole connectors. If your phone expects some weird-ass voltage, maybe you want to make certain it can’t possibly mate with anything that’ll kill it stone cold dead. Oh, and in that case pick a suitably different color. Blue seems to be the standard for 9 V, at least in the ham radio arena, for whatever that’s worth.
Add heatshrink tubing for strain relief (it might slip over the finished pins if you forget), wrap cold-vulcanizing rubber tape around the whole connector for more strain relief, and you’re done. It’ll make your charger cable resemble an anaconda eating a pig, but that’s OK with me.
Now the phone can commune with a bench power supply, a bulk 5 V supply, or nearly anything that you’ve hacked into using Powerpoles. It’s your job to make sure the voltage matches up!
Now, if you haven’t already, make a USB-to-Powerpole adapter. Alas, even though the phone uses 5 V, it draws too much current to charge directly from a standard USB port. However, I have a Black & Decker Pocket Power battery pack with a regulated USB outlet that can allegedly supply 250 mA and seems to handle the phone just fine.
So: cut a spare USB cable, verify that the red conductor is 5 V and the black is common (hell hath no fury like that of an unjustified assumption and we’re dealing with bottom-dollar suppliers here), crimp, align housings, add strain relief, and try it out.
This should work for any phone with a dumb, bulk-power charger. If you cut the cable and find three conductors, solder that devil back together again; there’s no telling what’s passing along that third rail!