electronic parts

Hello everyone.

I teach a robotic group, and last week we decided it was time to stop using kits and start doing something on our own. So we collected 20$ each and we need help at choosing the best stuff to buy.

We buy from local shops, 20$ is just so you know aproximatly how much we can spend.

We have tools already, we need just the electronic stuff. So i was thinking of getting:

Here is a hopefully simple question, and a little explanation to go with it.

Okay,here we go...

I am currently adding extra sensors and bits and bobs that eat up power on my robot and I would like to give my robot a bit more power to work with and so that it can run longer. That is simple thanks to12 AA batteries

My robot uses a Picaxe 28X1 and from what I have read it doesn't like more that 12V.

Here is the problem: my 12 AA's give out  18V ( and yes I did use a calculator! ) but I can only give my chip 12 of those 18V.