Not battery I don't think, it was turning over, but now won't turn, I suspect a faulty starter motor, it's 11 years old and a former Auto Windows repair van with 220k miles on the clock, that starter motor (if same one) has had some hammer. The engine is seemingly in good nick and I've had it serviced at least once, sometimes twice per year since I had it in 2015 and converted the back into a sleep compartment....
Fingers crossed it's not more than £500 to recover and repair, luckily it broke down locally so my friendly local garage can sort it.
Always something......