Starting issue

I have to use jump leads every time I want to start my car, battery is less than 12 months old. Alternator Maybe? What other things can I change or check?turns over ok just doesn't seem to have enough power until i put the jump leads on!

What size battery is it. Alternator any local car shop or Halfords should check it free or put a multi meter on. Should be 12v just over and when running just over 14v

Light sometimes on if it's alt. Check the plug onto alt and Earth

Sounds like it could be ok but something is draining it when your not using the car. You tried giving it a good run and disconnecting the battery until next time you want to use the car that would show a drain or again a multimeter and pulling fuses can show a drain

Drove friday 80-90 miles stopped for a coffee then wouldn't start again, i will try a multi meter and see what that reads.

When you say wouldnt start again.
Was it turning over but not firing?
Or you turn the key and nothing happened?

Check all connection from batt to earth to starter, use a multimeter to check voltage drop and also do voltage check on battery as lower than 12.3v means it not charged.
Don't rule out batt but do drop test and cell electrolyte test and also check for parasitic draw when parked with amp meter on battery ...

Check the conectors on starter motor.