I have a Z3 which has been garaged since the start of winter. It was started approx 6-8 weeks ago, taken out of garage, run until up to normal temp and then put back into garage. I tried to start it again on Monday 2 Jan 06 but it would not start. The dash lights come on but when I turn the key to start nothing happens. I thought that it may be battery or bad connection. Disconnecting neg terminal of battery caused alarm to buzz. On reading manual it says to charge via terminals under bonnet. I tried this for some hours but no luck. When I switch on I can hear buzzing from under bonnet. The radio led flashes. The headlights are dim. The windows work. However the radio does not light up.

Is it the battery that is completely flat or could it be something else. can anyone help