86 Intruder with battery or electrical problems?

[MOOCH]

Sometimes when I push the start button it makes a click noise and all the lights and power go out. I wiggle the battery and lights come back on. Try again and sometimes it starts and sometimes it goes out again. I checked all connections and cleaned both posts and the ends that connect to battery posts. It looked like the battery was moving around in the housing a little, so tightened up screws and put a small cut to size shingle under the battery to make sure it stays in place. I thought I had it cause no problems for a while, but every so offten I'm wigglin the battery. I have 2 friends that also had 86 Intruders and they both said they had the same problem. Could this be a model defect? Or is there something we're missing? Any suggestions are welcome. Thanks in advance.

[Wrider]

It's very probable it's just vibrating loose. My Volusia did that to me once, just had to re-tighten it and called it good.