Batteries did'nt work

Same problem with me today - except its my van battery.
Due at LTT, Harrogate at 9am for a leather restoration day with Jim Neal and 2 others.
Jumped in the van at 6:45 - dead as a dodo. Been ok for the last 18 months since I had the van, first time starter.
Got the breakdown assistance out, he left 8:30. He got it started, checked the alternator (14.2v) but after 10 minutes I had to stop the van to lock the front door - then wouldnt start again. I was going out to get another battery.
Now waiting for auto electrician to arrive early afternoon with a battery. He will check also to see if any other underlying problem.
Gutted I have missed a day at LTT Harrogate.