I recently got a 2007 XKR and I went to start it about an hour ago. When I pushed the button start (with the brake pushed down) all the electronics flashed, no engine startup and nowi can hear the battery constantly ticking in the back with the interior lights flashing on and off. The "smart" key is stuck in the compartment in the center console and won't release when pushed down. Depressing the brake pedal stops the battery's ticking but the lights keep flashing and nothing else happens. I don't want to disconnect the battery as I've had lots of issues from doing that in the past, and feel like hooking up a booster runs the potential of frying something since it (at least appears to be) sending a current through the car. Any solutions/suggestions are greatly appreciated. Thank you in advance.

What choice do you have OTHER than disconnecting the battery? Let it keep clicking until the battery is COMPLETELY drained?
I say, disconnect both cables, remove the battery and charge it for at LEAST 24 hours with a 20-amp charger. Then take the battery to an auto parts store and have it load tested. It may be a goner. If not, then the 24-hour charge should have remedied your complaints.

Welcome to the forums Kentonwill,

I would have (1) disconnected the battery and then (2) posted to the forum. As Cee Jay says - there is no other choice of action.

The number one cause of weird electrical/electronic behaviour on a modern Jaguar is a failing battery.

Graham

I suspect once you do a voltage check you will find the problem. The guys posting above is good advice. Let us know what you find.

I had a click back there the other day (sounded like a ticking clock), which turned out to be the blower relay switch, caused by a low battery. A charge fixed it

Precisely right @Buzzer . Batteries don’t tick, modules and relays do. And as everyone has stated, typical cause is there is not enough voltage to activate them.

Firstly why did your old battery die? Was it old age (4+ yrs) OR a problem with your electrical system! If you still have old one, try recharging (at least 10amps). .
If it recovers to 12,6-12.8 V's that will tell you nothing wrong with old one and you need to look elswhere!

Hope this helps; do you have code reader? a must have!! good luck...............

Cheers, Adrian, Founder Member Seattle Jag Club.

Adrian: this is an old thread…but in any case. It is clear that the problem was a dying battery…all the symptoms were there.