I had a problem last week with one of my V70 beltpacks overheating spectacularly. I couldn't get to it at the time to have a look myself as I was mixing the show out front but the actress and stage manager described it as "red hot" and "too hot to touch". She had to take it off as it was burning her back (hooked on bra strap so not contained in a cloth pouch.) They popped the batteries out to let it all cool down but she put it on again for the final scene and had to take it off as soon as she came of stage as it was reaching an uncomfortable temperature again. The batteries were very quickly flattened; presumably something in there was drawing far too much current, hence the rapid temperature rise.

This was the last night of an eight performance run; everything had behaved perfectly up until that point. Has anyone else experienced this? Is it a service / repair job? A known issue? Any advice greatfully received.