I have an HTC wildfire phone and I'm looking for way to trick this HTC to think it's connected to the original charger. I don't have original so i can't open it to measure. Right now for charging I'm using the USB port built inside a power inverter for solar installation. I also tried a car charger, rated as 2A, but still charging is very slow.
The problem is I notice the charging is very slow. I have took up it almost all night to get fully charged.
When I play music on phone and display stays on, it discharges faster than it charges.
I set up my little test experiment installation
For test's i got female usb plug, and i hook it up into my work bench psu, set to 5V.
Current draw 390mA
(hmmm, it's looks like safe USB current draw)
I start search internet, and found information about shorting data lines together.
I do, this but current not changed. Still 390mA.
Shorting both data lines to GND also won't help.
Does anyone have similar problem, and found way to make my htc think it's being connected to fast charger and took >1A charge ?
best regards
Best Answer
The way to indicate phones that they are connected to the wall charger is by shorting data pins as you have already found out.
Your problem might be different, some times you cannot achieve full charger current because of the voltage drop along the cable. If the voltage at the phone's input is not high enough (that value will vary from phone to phone, but it should definitely be higher than 4.3V), the phone will start limiting it's current draw.
You can check this by measuring the voltage at the phone during charging, if you can reach some measurement point. Or you can also measure the cable's resistance and do the math. To measure that resistance I recommend that you make 1A pass through that cable and measure voltage drop.