Slow charge warning when using a car charger

[Ron Kern]

This is what did work for my Lumia 830 charging error message, after purchasing the PortaPow 20AWG Fast Charge + Sync Micro USB Cable, PortaPow Fast Charge + Data Block USB Adapter, and PortaPow USB Power Monitor V2 was the Data Block USB Adapter. Any of my prior cables worked plugged into various cigarette lighter to USB power adapters with the Data Block USB Adapter. The PortaPow 20AWG Fast Charge + Sync Micro USB Cable although very nice and seemingly well made did not change anything when used by itself. The PortaPow USB Power Monitor V2 was pretty interesting to play with and see the actual voltage, amps and watts that are flowing to the phone. With the PortaPow Fast Charge + Data Block USB Adaptor inline the slow charging error message goes away and lets the phone charge at about 700ma instead of 500ma as measured with the monitor. Photos below show the charge with and without the PortaPow Fast Charge + Data Block USB Adaptor :

 

[QuadraFX]

What I have noticed is that Lumias expect data lines to be shorted. I have modified all of my chargers like this (not the cables, but the chargers - just shorted data lines) and I haven't used any resistors. As a result, my 930 is no more complaining about slow charging.

The problem is that manufacturers try to build "universal chargers" that will be recognized as a charger by trash devices like iphones or sam****s (or ****sungs ???) which are too dumb to use plain DCP (Dedicated Charging Port). They need resistor network coding (but nobody knows why...). Lumia isn't that picky - it takes what we give, just some chargers are recognized as DCP and others not, then the "slow charging message" appears.