Never had cracks or leaks in any battery. The cheaper ones just couldn’t turn the motor over after a few sessions. I’m not an electrical engineer or battery expert, but I’ll guess that the cheap ones were not designed to be laid on their sides and submitted to the vibrations associated with a kart. Either the plates within the battery are breaking or the isolators between the plates are disintegrating. So you are correct. It is a vibration problem, but only for a battery that wasn’t designed for those loads. The better batteries probably have stronger plates and isolators. That’s the reason for the higher cost.
LAD Specialties customer / tony kart / rotax / kt100