I plan to build some crazy machinery using circa 20 servos controlled by Arduino Mega 2560 and powered on batteries.
However I am struggling with source of power supply.
It is common hobby servo with operating voltage 4.8 - 6V
My plan is to put external power supply with 4x1.5V AA serial connected batteries which will give me 6V and 2200mA. And I have to of course share GND with Arduino running on 5V - which I hope is safe.
I am just not sure if 4 batteries are enough for current or whenever I am going to need to put there some condenser. Since some servos will be moving simultaneously. I guess I can always add another 6V parallel connected to give me more current.
techi602:
I am just not sure if 4 batteries are enough for current
No, I don't think 4AA cells will do the job.
Servos require more current than most people think. I've seen a lot of robotics projects struggle to power lots of servos. I used a 2S 5Ah LiPo with two 15A regulators to power the 22 servos of my hexapod.
I used some smaller regulators in this 32 servo demo but I still used a couple big LiPo packs.
4 AA batteries will usually power two servos, for a little while.
The general rule of thumb is to budget one ampere per servo, so your servo power supply should be capable of around 20 amperes total. More amperes is better.
You might consider the battery packs used in the 18 servo hexapods. You also might consider using UBEC voltage regulators as they are made for powering servos.