Dwaive,
I can see your having a hard time with this problem, and I think you need to test your battery in depth, starting with a fully charged battery, you need to check specific gravities on all cells then you need to check individual cell voltages and insure they are within two scale devisions of each other I.E 2.20v-2.40v then you need to load test each cell against the tilt relief valve watching for any reversal of polarity on any cell. Make sure the battery has stopped gassing off and is cold before you do these tests, Some times it can be hard to fail abattery Ive had them where trucks have cut out havinng only worked an hour, checked the gravites checked cell voltages all ok, but what it came down to was opotunity charging by that I mean the operator puts his truck on charge at dinner time and any other time he thinks suitable resulting in the battery capacity being reduced, which inturn led to over heating components. it happens.

Regards Titus