The Odyssey Extreme PC680 battery I changed out had a metal casing surrounding it. It was held on with just a few dabs of RTV Silicone and easily came off. Using an angle grinder I cut off one side and placed it in the rear of my battery tray. It does have a metal edge around the bottom which when a new battery was placed to the front of the tray it held it in place. A long zip tie around it all made it very secure.

A traveler never as enough storage and this gave me a place to store a sight glass plug, hand levers, a gear shifter and a set of small jumper cables. A coat of black paint and the upcycle was complete.

That's the way to do it!