Out of interest, I've had a butchers at my charger (proper plug into the wall job) and it only squeezes out 4w. If what I've read is accurate, I should probably replace it with something that has more balls, correct? It has been used to top up leisure batteries for years but the 190RC unit I use in my P38 is much meatier than any leisure battery I've ever hung from it.
Probably don't have any other options open to me, do I?
I wanted to avoid having to disconnect the battery if I could help it, but it appears I don't really have many options open to me. Checking if it was an open air car park was one of the first things I did. Although given the current ballache, I might take a power pack with me too, just to play it safe.