You need to get a new battery and the system professionally checked.

Looks like time for a new battery. I'm still puzzled as to why the panel goes into an unresponsive (and noisy) state if the power shuts off because of the earth-trip as opposed to a normal power-cut / shut-off, etc Is this common?

A mains power surge on power up can spike the panel, also if the battery

is faulty it can draw more power when the system is powered up and cause problems again and spike the panel etc.

Dave.

Looks like time for a new battery.  I'm still puzzled as to why the panel goes into an unresponsive (and noisy) state if the power shuts off because of the earth-trip as opposed to a normal power-cut / shut-off, etc  Is this common?

58730[/snapback]

Both states are loss of power, the panel has not been serviced and is doing exactly as it should.

Check the tracks around the battery terminals on the pcb as one could have blown open circuit with the extra current or it could be the voltage regulator open circuit it will be marked 7812 or 7912 if its a 12 volt regulator.