The above are great suggestions for engineering solutions to mitigate the terminal-loosening problem. You might also want to employ some non-engineering solutions:
- Train personnel to pick up batteries two-handed, by the body of the battery, rather than by the cables. Carrying batteries by their leads will wrench the terminals loose and may also damage the more-delicate internal connections within the battery.
- Go through your team's stock of batteries and align all the leads in the same direction. Adapt charging racks and old robots to the new standard orientation. This will discourage heat-of-the-moment efforts to reorient the battery cables when connecting batteries. It may also lead you to consider the cable orientation more closely when designing battery holders on future robots.