This shouldn't be a problem for those of us with a modern rectifier, but it
could still happen. And with disastrous results, especially if the bike is unattended when the diodes in the rec decide to go 'dead short'!
The heavier-gauge, unfused wire from the battery +ve terminal to the rectifier +ve output -- it's red/white -- should be protected by a fuse to prevent burnout. On the CB (CL?), the r/w wire connects to the rec +ve (r) at the ignition switch, terminal 'CH'.
Those of you wishing to prevent
this problem should install a 25-Amp fuse between the battery +ve post and this charging cable. Fuse carriers and fuse links are commonplace with car audio installers and readily available from most car accessory outlets.
If you 'show' your bike, just remove the charging cable from the battery, make up a short ring to ring tail -- max 50mm / 2" -- to connect the battery to the fuse carrier, then connect the removed cable to the other post on the fuse carrier; this method leaves the charging cable and its ring terminal intact and the fuse carrier could be removed for shows.
Thanks to Brewsky for almost setting his C77 alight!