Does anybody know how long the batteries that Radio Shack sells for the VEX last? If you charge them both up, and start using the VEX, how long will they go for?
Oh, and btw, does anybody know if the new parts are out yet? August is here. 
It depends on how many motors you use how much (basically, how much current you draw). Iâm not a Vex person, so I donât know exactly but according to the IFI specs, a battery pack is 700mAh and one motor draws 1.3A max so just divide .7 by (1.3 time the number of motors you use) and youâll get an approximate number of hours. Note that assumes constant max use so the actual time will probably be longer.
I searched âVexâ on radioshack.com
August has come, and so have the omni-wheels:
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=276-2165
If youâre talking about the 7.2V2000mAH (for the robot) and the 9.6V1000mAH (for transmitter), typically you should be able to get at least an hour, and possibly quite a bit more of runtime, depending on your robot and how you run it. Last night some of the team ran a ârobo-poolâ game booth open for public tryout at the local âNational Night Outâ celebration. Using the same robot they ran at IRI âEnter-Actionâ (squarebot based plus a manipulator) they ran pretty much continuously for over two hours without a battery change; I wouldnât have expected that. 
Two hours would be awesome. The other day I saw some flying toy device, that had a runtime of four minutes! Yikes!