Vehicle not starting. The road service provider found a flat battery.

This problem had occurred multiple times over several weeks.

This was a WM Series II Holden Caprice 6.0 L.

The battery was confirmed to be dead flat.

Replacement battery was fitted and a leak test done. There was no leakage at the time of test.

It was most likely there was a voltage drain causing the battery to go flat overnight.

The most likely scenario was that one of the modules on the vehicle was not going to sleep, causing the battery to drain.