No Turn Over, Ignition Weirdness

[mcycle-nut]

'82 GS850. Battery checks out at 12 volts now, had just came off of a battery tender before I started messing with it. Turn key, dash lights and headlight come on. Hit starter button, hear loud CLICK and lights go out. The only way to get them to come back on is to turn the key to a lock position and back. Crankcase is NOT full of gas, and one would think if the battery is weak, you would at least get weak lights and a "wrow, wrow" so why do the lights go out? What is that click?

[Cipher]

Your battery is not fully charging. fully charged is something like 12.6 and higher. The click is the starter solenoid engaging.
Quick and dirty boost from a non-running vehicle after letting the battery boost for a few minutes.