57 managed to lose Great Lakes in 2007 thanks to a bad battery strap. 2007 was the last year bumpers were optional. We had a cramped design so we could fit two beautiful wide ramps on the sides of the robot, so we actually had to remove a bumper to change batteries. Inspectors still wanted a strap, so a mentor went out and bought one. A 1" wide, somewhat elastic velcro strap, instead of the usual 2" wide stiff ones I was used to us running. Thursday and Friday were bad for us, because we blew up banebots transmissions driving the ramps. Had that all fixed Saturday, ended up the darkhorse 2nd pick for #1, 67 and 1114. We destroyed #8 in quarters.
Then this happened:
2007 Great Lakes Semi 1-1
That's us trying to move with a dead battery I was told was charged. Took forever to troubleshoot that, since I skipped that diagnostic, being told it was charged. (This was pre FMS having good battery data, too.) Not wanting to burn a time out, I told the students to slap in a new battery, and not bother with the bumper.
Which lead to this:
2007 Great Lakes Semi 1-2
That's the battery slipping past the velcro strap and flying out the back of our robot. Then eventually getting unplugged, because that wasn't an instant disable back then.
So yeah. Batteries are heavy. Don't expect something like a veclro wrap meant for as a cable tie to hold them in. Or actual cable ties. Bolted down aluminum or beefy 2" wide non-elastic velcro is the way to go.
And then there was that time in 1999 when our arm caught the battery cable that was sticking up and pulled it out as soon as we started the match...