Typically you will need a well attached galvanised steel tray with shallow lips to suit footprint of battery and locate base of same. Then a pair of long threaded J bolts to suit height of battery and hooking into the lips to hold it down. Many OE installations use a galvanised frame that accurately fits around the upper edge of battery shape and through which the J bolts pass to allow battery to be screwed down firmly into position. Picture below from my Land Rover illustrates.

[Linked Image]

The frame has to locate on battery such that it cannot possibly short the terminals.

Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone