Last month (March 22) the car wouldn't start. It came up with the error message. It was not able to jump from another car. I changed the battery and it worked fine. Now it's doing the same again. Last night the alarm went off twice and now this morning the car won't start. Any ideas?

Get the replacement battery tested by someone that knows how to so not at Halfords. 

Then the car checked to see why the battery is going flat.

 

What engine gearbox, age of car and miles done? 

1.6 Diesel, 2015, 90000

39 minutes ago, GBeams said:

1.6 Diesel, 2015, 90000

Has the new battery been coded in to the car?

No, not yet

1 hour ago, GBeams said:

No, not yet

The BMS will still think the old battery is fitted, which won't be helping.

My friend came round and sorted the battery and also gave it a jump. However, now, the clock is being and the stereo is not coming on. Any ideas?

Hopefully just a fuse.   Great care needs taken jump starting cars.