On Sun, 19 Nov 2017 17:27:10 -0500, rickman wrote:

A friend has an old Motorolla W376g phone and the charger can't be found. I
can get it to charge from a car charger I use as well as from a desktop
multi-outlet charger I have. But a couple of different wall wart chargers
won't charge it while they will charge any of my devices. I did a search
and can't find any details on why this might not work other than that
Motorola warns to only use Motorola chargers of course.

I've read that some phones or chargers have a resistor indicating the
charging capacity, but I don't recall which end has the resistor. Also, I
think this is not done for the lower current devices, rather for the high
current devices. I'm wondering if the phone is looking for this resistor.
Obviously I'll need to pay for a charger that clearly says it will charge
this phone. I just don't get what is happening in this case.

Any ideas?

I think they put a 1k ressitor from the USB+ to D+ so the phone knows
its a wall wart, other wise the usb protocol takes care of requesting
power from the hub.
My Old Razr is setup this way.

Cheers