As Richard said, they have 7.4 LiPo's. What gave you the impression they may have been 11.1v? The shop only sells 5v regulators for sensors like 5 volt ultrasonic sensors ect. No good for the servos though.

Ok, sorry got confused I was looking at batteries at the shop when I asked about the 11.1v.. because they didn't have a 7.4v but I found them, So i should be able to use the 7.4 battery without regulator..

Absolutely no problem. Yes that will be fine, and no regulator required. I'm using a 7.4v 5000 mAh LiPo with the EZ Robot servos and it works great.

Yes, you can use a 7.4V lipo for your servos "sans" regulators...However, sensors like the ping work on 5V so you will need a voltage regulator for these type sensors...

Thanks, gents..

No problem. Just incase you didn't know the ADC analog ports, UART, i2c and camera ports are already regulated to 3.3v no matter what battery you use. But a lot of sensors and some motor controllers that use digital ports will need regulators, unless they already have them built in. Anything your not sure of, just ask. Better to be safe than sorry.

Yep, thanks..