how should i mount my batteries??

what would be the best way to have batterie mounte so the dont come flying out in my robot is flipped?
the batteries are two 7.2v nimhs.

thanks, harry.

It depends on what youve built your robot off. If you have gone with the bulkhead setup made of lets say HDPE you could cut a piece out of it in 1 bulk head and stick in in there and build an extra support on the other end of the battery pack.
You could also get some thinner polycarb and bend it around the pack and bolt it to place.
There are probably hundreds of ways of mounting it