Phone Charging
03-10-2017, 10:16 AM
#1
Member
Thread Starter
Phone Charging
In my 2012 E350, I can charge my phone off of a USB 12V adapter (aka cigarette lighter adapter) twice as fast as I can the USB in the arm rest console. I'm assuming it's the difference between 1.2 and 2.4v USB plugs. Not being one with electricity or how volts/amps and such work too much, is there a way to get 2.4v out of the console plug? I hate having my ash tray open with a cable and would much prefer to stick my phone in the arm rest console, close the door and charge while I listen to music. Maybe a new fuse or something? I don't know....thanks everyone!
03-10-2017, 01:02 PM
#2
Senior Member
So to clarify, it's actually 1.2A. The amperage is the difference. Voltage will usually be the same regulated output around 5 volts (check your wall charger to verify output).
simple math
P=I*V (power in watts = current in amps * voltage)
V=I*R (voltage = current in amps * resistance in ohms)
this can be converted to I=V/R or R=V/I
since your voltage is likely constant, if you want to increase the amps you will need to decrease the resistance.
so find your resistance by R=V/I --> R=5v/1.2A = 4.16 ohms
if you desire that 2.1A output, replace the resistor accordingly. R=5v/2.1A = 2.38 ohms
simple math
P=I*V (power in watts = current in amps * voltage)
V=I*R (voltage = current in amps * resistance in ohms)
this can be converted to I=V/R or R=V/I
since your voltage is likely constant, if you want to increase the amps you will need to decrease the resistance.
so find your resistance by R=V/I --> R=5v/1.2A = 4.16 ohms
if you desire that 2.1A output, replace the resistor accordingly. R=5v/2.1A = 2.38 ohms
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matthew121170 (03-10-2017)
03-10-2017, 02:39 PM
#3
Member
Thread Starter
So to clarify, it's actually 1.2A. The amperage is the difference. Voltage will usually be the same regulated output around 5 volts (check your wall charger to verify output).
simple math
P=I*V (power in watts = current in amps * voltage)
V=I*R (voltage = current in amps * resistance in ohms)
this can be converted to I=V/R or R=V/I
since your voltage is likely constant, if you want to increase the amps you will need to decrease the resistance.
so find your resistance by R=V/I --> R=5v/1.2A = 4.16 ohms
if you desire that 2.1A output, replace the resistor accordingly. R=5v/2.1A = 2.38 ohms
simple math
P=I*V (power in watts = current in amps * voltage)
V=I*R (voltage = current in amps * resistance in ohms)
this can be converted to I=V/R or R=V/I
since your voltage is likely constant, if you want to increase the amps you will need to decrease the resistance.
so find your resistance by R=V/I --> R=5v/1.2A = 4.16 ohms
if you desire that 2.1A output, replace the resistor accordingly. R=5v/2.1A = 2.38 ohms
