Hi,
It does sound like you need a new battery especially if it is more than a few years old. Most parts outlets and garages can't check a battery properly. The issue is increased internal impedance which causes the voltage to drop under very short high current loads. Some cars are susceptable to this, the design answer is more local stoarage (capacitors) close to the loads, but they cost money. One last check, before spending on a battery, is the battery connections including the negative "earth" lead. Make sure all the connections are clean and tight. Also check the fuse "box" on the positive terminals for loose connections. If all OK then try a new battery. I prefer a known brand such as Bosch, Yuasa or Varta but the Halfords premum range is OK. I'ts not just Cromas or Fiats that suffer from this. A neighbour has a Merc which had intermittent non starting which the dealer had not fixed after a couple of attempts. I found it had a positive terminal fuse box like my Croma and one of the nonnections was slightly loose. About 3/4 of a turn on the nut and no more problems.

Robert G8RPI.

Hi Robert, thanks for the reply and information, I am not ready yet to lose the Croma so i hope the problem is not serious. I will have a check tomorrow, much appreciated more than you know