I'm building a system of portable devices for paintball/airsoft use, a sort of capture-the-flag gadgets. The code is written, most of the hardware in place and the casing is coming around very nicely. I have an Arduino Mega with an LCD shield, a 3.2" TFT and a DFRobot mp3 player module hooked up to one 3W recycled speaker (see image below). All of this x3, to make 1-2-3 gadgets.
Enter the power stuff. I suck at the electrical side of this.
The best solution by far is to use the same kind of batteries we use when playing, which is the regular RC LiPo batteries with 11,1 V, 11000 mAh. I need it to feed both the Arduino/TFT and the mp3 module (which runs on 3,3V).
What is the best solution for this? Can I hook up the Arduino directly to the battery or will that fry it? I'm a bit pressed for time, so how about just stripping clean a couple of car chargers and using the internals to convert the power for the Arduino, then feed the mp3 module from the Arduino 3,3V output?
Or are there better ways?