Fault Phenomenon: Putzmeister M60 battery is normal when cold. During high summer temperatures (operating temperature), the battery bulges, capacity decreases, and eventually fails to start.

Troubleshooting Process:
– Checked generator voltage: voltage normal.
– Checked battery hold-down: secure.
– Checked battery ventilation: good ventilation.
– Measured individual cell voltages at operating temperature: found voltage imbalance.

Root Cause: Internal battery plates sulfate, and gas expands at high temperatures, causing bulging.

Required Parts: Battery assembly.