I want to put a bigger battery in place of my stock Infiniti battery in the stock place. The stock OEM battery is 12.3"/6"/7". The battery I want to put is is a Powertech which is just around 13.5"/7"/7". The engine bay will allow it, however how do you go about keeping the battery in place? The stock OEM battery fits in a casing which keeps the battery secure, however are there aftermarket cases for batteries that I can place in my engine bay? Thanks!