Hi Tony, do you know the age and history of your battery. The ability of the battery to start the car is no longer the definitive indicator of a good battery as the sensitive electronics of a modern car, especially a Jaguar must have a stable voltage supply at all times.
If you don't know the battery history, or if you do know that the battery is more than 5 years old, then the first part of the fault finding MUST be to change the battery. As your car is a 2016 model, it could well still have the original battery installed - probably has a Jaguar sticker on it.
Ensure any replacement battery is of the correct rating and dimensions as it must fit into the battery tray and be secured - an MoT failure for an unsecured battery.
Go to the Kwik Fit website and locate the "Battery" tab, enter your registration number and post code and then click search. The site does all of the hard work for you and once you have found the correct battery, you can run a separate search to find it at the best price - don't need to purchase it from Kwik Fit of course. A lot of folks suggest the Battery Mega Store as offering good prices, but remember you need to be able to fit it, or pay around £30 for a local garage to install the battery you purchase.
Once you have confirmed the battery history and / or change, come back and let us know for further advice.
N6 JMX