UPDATE: today I jumped started the car,once I disconnected the jump leads the voltage at the battery dropped quite quickly.If I turned on the headlights the car would stall.I'm thinking the alternater has had it.
I also tried to change the battery light bulb,but as mine is a late car it has led warning light bulbs.
Can these be changed?I'm hoping that if the alternater is at fault,a new one will also sort the battery warning light.
tony