It is possible to buy just the 9.6v batteries?
and where can i find them if you can buy them individually?
I know you are able to buy the 7.2v batteries, but why would you have to microcontrollers and only one remote?
To find out if you can buy something from VexLabs, look here. http://www.vexlabs.com/vex-robotics-all-products.shtml
I don’t think that they have any secret offers hidden elsewhere in their web site. 
Some Radio Shacks near me have some 9.6V (1600 mAH?) battery packs on sale for $9.99. They have been that price for many months. They fit in the transmitter as well as the Vex battery pack.
RC/Hobby Shops will offer them too.
Blake
Are they the batteries designed specifically for the transmitter?
because that is what i am looking for, and my radio shack has crap
they dont even have wire that i need
No - But they are the same size and shape and current rating as the batteries sold by Vex. The also have the same connector and the same length of wire.
If you want to wrap one of them in blue tape in order to make it the same color as the Vex model, you will have to do that on your own
RS isn’t the only source by any stretch. Look in an RC/Hobby shop or look online.
Blake
Walmart, cheap, good, both sizes, dare i say more?
just go to costco, go to where they sell batteries, and buy some >2000 mAh duracell rechargable battieries. They’re Nickel Metal Hydroxide, which- i hear - is better than Ni-Cad. I use 6 duracell rechargables from costco for my bot’s battery. Costco’s deal is good, because it includeds a charger that only takes 15 minutes to charge 4 batteries at a time! the only problem is to find where you can buy spare batteries, which i’m trying to find out.
Minor correction. The correct word is Hydride, not Hydroxide. They refer to different compounds.
for spare rechargable batteries, radioshack has what you need (the higher the mAh rating, the more power and run time you get.) dont be afraid to spend $4 a battery, it is worth it in the long run!