Thank you for coming back so quickly. I suppose I did wonder if that might be the problem. As its not really showing any change in charge on the battery charger after 6 hours, does that definitely confirm that I will have to buy a new battery?

The OP said she had disconnected the battery in March so it might be ok. The only thing is, We have no idea what the charger is that she is using.

With a decent charger it is probably going to recover.

By disconnecting the battery and the fact that it hasn't been freezing the battery should have survived. It might take a good 24 hours with a trickle charger to get any meaningful charge into it. Modern "smart" chargers often will not charge batteries with less than 8 volts in them, the way round this is to jump the battery from another one and charge them both in parallel. Preferably the charged battery should have a smaller capacity than the flat one to avoid putting too much current into the flat battery. Motorcycle batterys or those little jump starter packs are great for this type of use.

Edited by SteveLee on 14/09/2013 at 11:14

The OP disconnected the negative terminal in March after driving the car to/back from an MOT and was a very sensible thing to do.

Now the OP doesnt know if her battery charger is in fact charging - no surprise there - most battery chargers are useless bits of cheap tat that break or stop working within weeks and/or dont inform any unqualified person anything about what they're doing/not doing. And as pointed out a lot of chargers are so poorly designed they will refuse to charge a flat battery

I suggest the OP reconnect the battery and try starting the car. If it struggles to turn the car over, the next step is to seek someone with jumper leads for a "jump start".

Remember the car may take a fair amount of turning over to start as its been stood a long time and the fuel system may need priming.

If the battery cant turn the engine over at all, then the OP should seek assistance from someone who is more technically skilled - if the car driver was in the AA/RAC or had other breakdown cover then maybe that membership is still valid and she can call them.

Edited by brum on 14/09/2013 at 18:53

Thank you all for your advice. The charger is labelled Sealey Power Product "Charger 10" EN60335-2-21. It is a 6/12v charger. I put the battery back on charge this morning and after 3 more hours (making 9 hours in total) the dial showed a drop from just under 3 amps to ~2 amps so I guess something is working? I turned the charger off after the three hours as I didn't want to risk 'cooking' the battery because I seem to recall that was a possiblity? In view of the comments about charging it for up to 24 hours I charged it for another 2 hours this afternoon before turning it off again. When I switched it back on this evening to check, the reading was ~1.5 amps. I turned it off once again as I don't know what reading I should be aiming for now. The next thing seems to be to reconnect the battery and try to start it. If it should start, I'll take it for a a run of 20+ miles. Thank you again and I'll let you know what happens.