ive had a similar problem, left the interior light on for a while and eco mode and red battery light flashed, the battery was strong, as the horn and headlights were perfect, but the starter made no attempt to crank the engine.I had to put a small home charger on,but hardly half a amp would go in? (BATTERY GOOD) Started ok mins later.interesting idea about take of positive terminal then replace, i will do this next time if it happens again?
old biddy, September 2010