if a servos operating voltage for e.a. is 4-10 volts does that mean that each servo uses about that much voltage or does it mean that the battery has to be between 4-10 volts

Hi battery Needs to be between 4 to 10 volts

The nominal Battery Voltage differs between what type of batteries and servos you are using. Digital servos use up more battery capacity, and analog, use up less.. It also depends on how many servos you are using.
The servo operating voltage is 4-10 volts as you stated. It doe's not mean the servo will use all the voltage. It means you need a battery pack between 4-10 volts. Many people use 4.8 v battery packs. I perfer to use 6v packs around 2700 mah. If using battery packs over 6v, you will need a requlator. I don't think you are at that stage yet. Hope that makes sense.

i want to buy a 11.1v lipo battery from www.hobbypartz.com but i can't find a single servo that can use 11.1 volts

twang905,

It seems that you have some confusion regarding voltage.

The voltage is the difference in "electrical pressure" that makes the electrons circulate along the circuit (named amps) and generate some work (watts).

In the direct current systems that our planes use, that "electrical pressure" or voltage is determined by the battery.

Thus, for the same circuit composed by wires, switch, receiver and servos, a 6.0 volts battery will push more amps around the circuit than a 4.8 volts.
In the same way, a freshly charged 4.8 volts battery (which in reality has 5.0 volts) will push more amps around the circuit than when almost discharged (which in reality has 4.6 volts).

Now, the manufacturer of the consumers of the circuit, like the servos, rate them in a range of voltage for which they will perform better.
If the voltage of the battery is below that range, the servos will be very weak or even nonoperational; while they will be damaged if the voltage of the battery is above that range.

i'm kind of confused but can someone just suggest what servo i can buy to go with a 11.1v batt from www.hobbyparts.com

My question is, I want to build a foam RC model.( I looked at the parts.) The motor uses 11.1 V battery, but the servos use 4.8 V. Can I use the same battery (11.1V) for both the motor and servos?

You need a regulator

Ameyam

The servos typically use a circuit off the ESC that goes to the RX and delivers the right lower voltage to the servos (Long multicolored lead) out of it. The RX also delivers control data to the ESC to control the motor. It sends the right power data to tell the battery, through the ESC, to control the motor. This power is a combination of higher voltage and frequency's that vary to the speed your TX throttle stick  sends to it. Your motor gets the power it needs to run at the speed you tell it to run via the throttle on your TX. 

Don't work about using 11.1V battery on it.  Servos will get the voltage they are designed for.

Hope this is not too confusing. If so I'll clarify it better.

AltaTed

As AltaTed has explained, you don't need to worry about it.

All the electrical models that I have seen are fed from the same battery: the motor "feels" the whole voltage of the battery, but the speed controller (that has a built-in Battery Eliminator Circuit (BEC)) reduces the voltage that is fed to the receiver and the servos to the proper level.

Recommended reading:

http://masportaviator.com/2005/09/07...ctrical-power/