My first TC was a Pro4.I used the battery strap that came with the kit.Not only did my batteries fly out in a crash,
the chassis had a bad tweak .
That is when I went to tape.
I NEVER lost another battery in the Pro4 and have yet to eject one in my FK05!!!
The last thing you want is to have a battery come out.Things get all nasty.(smell colour etc..)
Cool thing to see if it's not YOUR car!!!
Also seen some batteries bring the esc and receiver along with them.
Tape for me all the way.