The message
from The Natural Philosopher contains these words:

you won't even start a modern car on 6v.

The neighbour's Kia got upset with me jumpstarting it. Had to charge the
battery even though it was cranking over easily fast enough for a petrol
engine. I didn't actually measure the voltage, but it was damned
annoying.

--
Skipweasel
Pay no attention to that man behind the curtain.