Bit of an update on this.
After my initial success it was soon found not to be the case, once I'd driven the car again the EML came on.
Didn't when driving to try the coil packs, and then only when I touched the accellerator pedal.
Ordered a cheap code reader, which turned the light out until restarting the engine and drive where it would come back on.
Unfortunatley the code reader was throwing a throttle position code which confused me a little.
Anyway, Friday night moved car to wash it then back again seemed to kill the tired battery and it failed to start.
Ordered a new one, along with another 3 new coil packs using Euro Car Parts 25% offer (annoying as it was 30% Thursday evening
)
All fitted this morning, and all is well, EML went straight out as it should, radio didn't need code entering and all dash lights associated with removing the battery have gone out.
I'm guessing the EML light was due to the new coilpack along side the older 3 and the battery was a coincidence, as It's been 'tired' since I got the car 18 months ago and has lasted 12 months longer than I expected!
Hopefully this will help someone else who has coilpack troubles in the future .