Originally Posted by ta_man

I had the same issue - I machined the rear battery mount to take a little material off it and the batteries are easier to get out.
Also the battery makes a difference - the HV shorties from RCJuice are easier to get out than the Non-HV shorties that they sell.

I found the tool that Traxxas includes with many of its cars for assembling the joint in the slider axles works well to pry the battery out. It is just a very thin, very hard piece of steel.