1) Will it burn your phone? NO!
2) Is it safe? YES!
3) Can You order any KITs from us to do this item by Your own? YES!
4) Should You be proud of it? Definitelly YES!
1. While summary voltage of appiled AA-cells is higher than 4.2 V (max voltage of your cell phone battery) it will charge your phone
2. It is better to use the same four AA-cells
3. Accumulators or old-school acid cells no metter but it is better to use accus while You can recharge them
4. diode and resistor ARE important
5. Diode may be any Schottky diode with a forward current greater than 1 Amper
6. Resistor limits current and accepts the voltage difference between Charger and phone. You may use resistor of the SAME value but with a bigger power dissipation
7. Until Your battery inside Your phone -- no overvoltage for phone happens. Battery keeps voltage in the phone's schematic on it's own level, untill it is charged full
8. after fullcharge no overvoltage happens cause Your phone automaticly switches off charging when battery is full