Really sorry to have to ask this.....

[tankme]

Some of us also like to seal up the bottom of the hull with a resin pour when removing the battery box to add some structural rigidity back to the hull. Only takes 4-6oz of resin, but if you do this make sure EVERY LITTLE HOLE where resin can escape is sealed up. I tend to use a hot glue gun to seal holes before the pour as the clear resin makes the glue pretty much invisible after the resin hardens. Finding a hole or multiple holes where resin is seeping out after a pour is not fun at all and quite messy. Ask me how I know...

[RobW]

Or brace across the hull with plasticard. Placement can be important to avoid losing the space you just gained.... It has the added bonus of letting you separate the motors from lose wires: gearboxes don't like wires!