I am working on an autonomous robot which is controlled by my RPi 3. I was concerned about how to power up the Pi, so I dissected an old laptop battery and got 6 Samsung ICR16850 LiPo cells from it.
Each cell gives 3.7V with 2200 mAh. If I use two of these cells connected in series, and pass them through an L7805 IC for voltage regulation will it be enough to run the Pi?
Please note that there is an Arduino connected to the Pi as well, so the USB ports might draw more power. Also, how should I check the amperage?
Here's a technical description about the battery- http://lygte-info.dk/review/batteries2012/Samsung%20ICR18650-26F%202600mAh%20(Pink)%20UK.html Please note that this is the pink one(2600 mAh), I have the green one(2200 mAh).
So is using two of these batteries together is fine? And how do I get the amperage to be 2 amps?