08 N/A Clubman won't start
 

I have just done the timing chain in my sisters car yesterday, the car started and and ran fine. I took it to the garage to put new tires on today and when they went to bring it in it would not start. Battery is shot in it but it would always start when boosted, lights on the dash all come on when the key is in. I'm going to check the ground and all the connections I removed when doing the timing chain. Any other advice?