golf m5 compleetly flat car battery now trying to jump start

[coops0116]

golf m5 compleetly flat car battery now trying to jump start goes into imoboliser activated?
Can anybody help please as I start a new job Tuesday
Thanks in advance
Coops

[larrylamb11]

With something like this you often need to connect the jump battery to the car, fool the car into thinking the bonnet is shut (bridge the bonnet switch), then try locking and unlocking with the key/fob. Then go for ignition and start.
Have you got a manual? does it describe a sequence in there?

[E-bmw]

As above, that is a likely scenario.

Personally, my first thought would be to remove the battery & charge it overnight, then test the voltage (should be around 12.6 volts) and if it is good, refit the battery and try to start it after resetting the alarm/immobiliser.

Also.

What caused the flat battery?