Today, after a 4 days of daily use (4 starts and 2 drives of 15 minutes) of use, the XK8 refused to start, all the symptoms of a flat battery.
Indeed, the charger was on full output to recharge.
When started, time to check the voltages,
Battery 13.2V
Fuse box supply posts under bonnet 14.02

Removed the supply fuse cover in the trunk, voltage at both sides of the fuse 14.02.

So, 0.8V drop between the fuse and battery. Not good.
Touched link lead and it was very hot.

No sign of corrosion or broken conductors in link lead.
Just recrimped terminals and will see how it goes once I have applied some new insulation.