I need a suggestion about the rating of the battery I should be using for my connection. I got 18 SG90 servo motors for my hexapod.can someone suggest me the kind of lippo battery I should be using. Also the legs of the hexapod are jittering what should I do for the jittering problem ?
Measuere the current, then yozu know what you need.
Servo jitter can have multiple issues: powersupply to week, pwm signal juttering, bad connections ...
Your 18 small servos might draw up to 18 amps if they are all under load at the same time, though I suspect 9 amps would be more realistic. You need to look at the C rating of your LiPo battery to understand how many amps it can safely supply. To give you an idea I have some very small 240mAh LiPos with a 20C rating which means that they can produce up to 20 x 0.24 = 4.8 amps - of course they would be depleted very quickly at that rate.
...R
The SG90 servos are specified for 4.8-6V, which is not provided by LiPo batteries.
You will need a 2S or 3S battery pack and a very high current step down voltage regulator. This regulator would work well. Because it is a switching regulator, the battery current draw will be significantly less than the regulator output current.
Most people use heavy duty NiMH battery packs intended for radio control vehicles, which do provide the correct servo voltage.