Hello all.
I am about to build my first robot and I have 3 servos on it (two for wheels, one for moving an ultrasonic sensor, all 4.8-6v). I was wondering if one 4xAA battery (rechargeable pack) would be enough? Or do I need a second powering source for the Arduino mega board?
Sorry if this is a stupid question, it's stumped me.
Thanks!
hello
Normally Servos does not need an extra battery pack because they can worck with the electricity that is provided by the arduino.
but, about wat kind of servos do you are talking?
does not need an extra battery pack because they can worck with the electricity that is provided by the arduino.
What . . . .? 
Hi, if you are running off battery power, then you will need a separate set of batteries for the servos, they can draw a significant amount of current.
Because the batteries are not a regulated supply their output voltage will vary with the current load, this can and will cause problems with the arduino if they are on the same power pack.
Tom...... 
Pota_Mota:
hello
Normally Servos does not need an extra battery pack because they can worck with the electricity that is provided by the arduino.
That comment needs a karma- button.
It's unfortunate that some tutorials say you should / could / can power a servo off the Arduino's 5V, but it's nonsense. You should allow 1A each: worst case is they all stall together so you should be able to supply 3A
Hi, yes, I have run one of the tiny el-cheapo servos off the arduino,but put them under load and its a different kettle of fish.
Tom....
Really are you gonna use servo motors for wheels ?
zaxarias:
Really are you gonna use servo motors for wheels ?
If they're continuous rotation servos, it makes sense. Easier to control that DC: no h-bridge required for example, and one control wire per servo instead of 2 or often 3.
JimboZA:
zaxarias:
Really are you gonna use servo motors for wheels ?If they're continuous rotation servos, it makes sense. Easier to control that DC: no h-bridge required for example, and one control wire per servo instead of 2 or often 3.
First time i see a project where servos will be used on wheels..
zaxarias:
First time i see a project where servos will be used on wheels..
It's not common.
Real question is, is a servo still a servo when it's a continuous rotation servo?
JimboZA:
zaxarias:
First time i see a project where servos will be used on wheels..It's not common.
Real question is, is a servo still a servo when it's a continuous rotation servo?
Maybe it is a servo dreaming of being a DC motor 8) 8) 
First time i see a project where servos will be used on wheels..
Continuous rotation servos are commonly used in basic small robots.