Hazards when connecting battery

[Pond]

Does anyone know why if I connect my battery (2001 Z3) after more than a couple of hours disconnected the hazards flash continuously until I turn them off at the switch? The switch doesn't flash, so I have to turn the switch on and then off to cancel them. I am presuming it is something to do with the alarm, but don't know what, or why.
If I re-connect the battery within [say] an hour it doesn't do it.

 

[Synclare]

My 2.8 p/f and 1.9 f/l both behave the same as you are experiencing. Press the non flashing hazard switch on/off sorts it. Quirk of the car I guess.
Never tried starting it with hazards going though, might be worth it to see if immobiliser prevents a start.