
I'm using an adjustable power supply (0-18V and 0-3A) to power my EZ-B v4. But it seems that every time I'm moving some servo's a bit too fast, the controller loses connection to my wifi. As long as I make sure the movements are very slow it usually doesn't happen. Could it be that my power supply can't deliver enough amps? Would using a 2 cell Lipo fix the problem? The only Lipo's I've got lying around right now are 3s, so I'm not able to test it right now.
It is just as you suspected and as Josh has confirmed, your power adapter just can't handle the in-rush current requirements of the servos and drops the voltage (browns out) as a result.
We definitely recommend using 2S (7.4V) 25C LiPo batteries, that's what we use for our robot kits.