The servo motors are usually powered by batteries. This power source is then regulated to 5V (using voltage regulator). Amount of voltage depends on applications needed. 5V voltage is enough to drive torque to perform useful motions. Commonly, servo motors are powered by smaller batteries like Nickel Cadmium ('NiCd') or Nickel-Metal Hydride ('NiMh') or even the latest; Lithium Polymer ('LiPo').
Battery type. You have 3 choices to choose from. Nicad, Nimh and lithium mines ontario. Nicads have been around for years and are a great choice and all the major brands have them. Nimh offers more run time in the same size package although your choices are a lot slimmer. Panasonic is the main one for the Nimh although you will find others. The premier choice, in my opinion is the Lithium battery tools. It's hard to believe the run time you can get from such a small battery. Don't worry about the power from such a light battery, remember, 18 volts of Nicad, Nimh or Lithium batteries will give you the same power.
Most battery packs are of the Nickel-Cadmium (Ni-Cd) type. These offer reasonably long cobalt mining copyright life and will take hundreds of re-charge cycles. As far as re-charging goes, I recommend giving a short shock burst into the air every month or so. Make sure the spark is as loud and strong as when you first tried it after your first full charge. If not, re-charge.
3) Battery life: a combination of a battery's drainage and capacity and is normally seen quoted for standby and/or talk time. Usually quoted for ideal conditions. But, remember, that most of us will rarely use a battery full under ideal conditions all of the time. And analog mode will drain a battery very quickly. And be careful when in areas that are difficult to get coverage such as buildings or tunnels since your phone battery will drain because your phone will continually be trying to make a connection.
One of the cool features of a lithium drill is that the drill maintains it's power until the battery is drained then it just quits. With this in mind, if you get to the site and your battery is dead, if you charge it for 5-10 minutes, you will have full power (I said full power, not full run time. You need the full charge for both!). This is a great trait of the lithium mines ontario drill and many trades and service techs will benefit from this feature.
Li-ion Batteries last longer and charge quickly. A Li-ion battery and a quick charger make it possible to work all day with a cordless drill without stopping.
So, it's easy to see how a lithium 18650 battery, and Li-ion cells in general, have found there way into the homes (and hands) of many modern consumers.