Aston Martin DB11 Owner's Handbook Manual page 39

Emergency Engine Start
If the keyless start system fails to start the vehicle, the engine can
be started with the emergency start system.
To start the engine:
1. Lift the battery cover (A).
2. Press the cap release button (B) and remove the key end cap
(C).
3. Move the armrest back to at least position "1" (Refer to
'Powered Storage Box', page 3.31)to expose the cup
holders and the emergency ignition cover.
4. Remove the emergency ignition cover (D).
2.13
Vehicle Security