Mark, they are terrible at draining batteries, If it starts after 3-4 weeks without a conditioner attached you'll be lucky and its nothing to do with your battery condition. When I first had my Morgan 2010 with what is fundamentally a modern engine and management systems I didn't dream that this could be the case. Testing the battery state after a three week discharge I assumed that the battery must have been stuffed! So I bought a new one and yes, it just kept doing exactly the same thing You can put a battery isolator switch in but there have been cases of these blowing the electrics when switched on again especially if the car isn't stored in perfect conditions. I bought the Ctek battery conditioner, one of the top options from the range and have wired it up to be an easy connection plug in as the battery is rather inaccessible for a simple connection. When I swapped out the battery the original was fully charged and I stored it on a shelf in the workshop, I had forgotten about it and about 6 months later my son's VW Polo battery failed so I thought I'd give it a go on his car. I fitted it and expected to charge it overnight but guess what It fired the car up instantly and its still working fine 3 years later!
There is a constant draw on the battery when the ignition is off as the management system has not been fully integrated into the morgan or made to function well enough in that it does not enter a sleep mode and shut down fully.. After hearing some tales of disasters around PCB failures related to isolation switches I thought keep it simple and go with the Ctek, think mine is the 10.0 version and its not let me down so far.... I on the other hand have by forgetting to reconnect it when putting the car away!
