Samsung Galaxy Y Charger Hack

My old and trusty Magellan GPS is due for retirement.  The rubberized cover is now starting to peel off.  One-third of the LCD display is busted due to a fall while travelling at about 80kph.  I used it mainly for tracking back my traveled path and also as an alternative speedometer..etc.  It is really a bare unit with only the basic map installed.  I just used my imagination to make the most out of the gadget.

Recently, I was given this Android phone called Samsung Y with built in GPS.  And so now, the Samsung Y can now replace the old Magellan.

There's a problem though.  When the GPS sensor is ON, and off course some navigation applications need to be active as well, the phone battery lasts only for some hours.  The logical step therefore is to find a way to extend battery life or have a charger always connected.  The phone charges via USB, by the way

I bought a CDR King 12V to USB charger for less than 100php (for those residing outside the Philippines, CDR King is a well-known shop selling electronics and computer stuffs.)  Sure, it charges the phone but only when it is OFF.  Once the phone is turned on, charging stops.  This is unacceptable.  How can I use the phone's GPS function if it is turned off?

Some hacking will be required.  Before proceeding, please read my warning below.

DISCLAIMER :  IF YOU DECIDE TO REPLICATE THIS MODIFICATION, I WON'T BE LIABLE TO ANY DAMAGE THAT IT MIGHT CAUSE.  DO THIS AT YOUR OWN RISK.

After opening the casing of the charger, I noticed that the two middle pins of the USB connector are just floating.  I took a 10k resistor from my parts box and used it to short the two floating pins one by one to either GND or +5V.  The phone still won't charge.

I took another 10k resistor and shorted both floating pins to GND.  The phone beeped and the charging icon came up.
Soldering finalized the hack.

This is the intended application.

It looks like more effort will be needed but at least the phone now charges while it is turned ON!!!