Anyone seen the moon recently? Or the sun? I think we're on the wrong planet - will extract old faithful Merlin to get some times.
Bashing through the og we were earlier, black squally night, occasional glimpses of brilliantly sparkling stars. Vaguely aware of new banging thump, intermittent, sporadic - seemed to be coming from stbd q-berth so put it down to movement of bags of food cans and empty fuel drums squashed in there. A bigger roll than usual (meaning a very big one indeed) bigger crash and all the lights, instruments, electrics generally karked. Dark dark but for faint glow of some LEDs and the USB gadget powered by the computer. Dooon't Paaanic! Reach for blue towel, wake Pete and start closing everything down and begin diagnosis.
No radio (connected directly to the battery, bypassing the isolation switch), no engine start from either battery, no wind generator, lights, instruments. Oddly, some LED indicators on switch panel still working along with 12v dc outlets. Unpack q-berth to get at main battery box, nothing obvious, big shunt connections ok - 12.7 v from each battery so - phew! - we haven't cooked them - then a big lurch and the two big batteries and all their rats nest of wiring moved a couple of centimetres inside the battery box. That's it! The new crashing noise. Feel and prod all the terminals and massive wires and Eureka! the main negative lead runs from the terminal through a slot cut into the top of the rear side of the battery box and off to the shunt and it has parted inside the insulation over the crimp to the spade terminal. A classic stress fracture - the end of the 8mm copper wire looked just like a bit of brown cheese. While still held together inside the insulation there must have been just enough current to keep those LED's glowing.
From there, what to do? We don't carry spade terminals that big, or a crimper either. But we do have cable clamps to bypass shroud failures - big ones! We clamped the broken end of the wire to another big negative wire crimp on the battery terminal and bobsyer! Back in business. Sounds easy but imagine doing it with your armchair rising and falling 15 feet or so, rolling through 60 degrees and pitching so your nose hits the table in front of you. I'm gobsmacked that the electrics kept working so well for so long - hanging by a thread it must have been for quite a long time.
So - the cause - it seems that the negative lead going through the slot must have been holding 30 kilos or so of battery more or less in place for the two years since they were installed, but with a bit of movement happening in the heavy weather stuff causing the wire to flex at the crimp, weaken, the movement to increase, the wire to strand and eventually part.
And the fix - all y'all make absolutely sure that your batteries are wedged as tightly as possible into their boxes as well as being strapped down. We banged a couple of softwood plugs into the space for Berri and it will all get us home.
Here endeth the lesson for the day.