since this is the third time it has happened, I can't be the only one. The connection blade on the battery broke off at the case. Just a tiny bit left, I'm trying to salvage this one. I threw two away for the same thing.
You are absolutely right... If you never moved the connector up and down it probably would last the life of the battery, especially if you otherwise abused the battery, but alas I do move my batteries around searching for the best possible setup. That being said, I will never buy this type battery, with this type connector, again. even if I go back to sla, i will buy the ones with the post and bolt connectors. The larger ones have those.vibration....battery boxes....stop....maybe the weak link is the connector...try making a new one...a better one