48V is the limit of not having to legally* do any specific sealing or covering. 48V won't kill you but it does tingle and will still make a mess of any metal that touches the terminals. And of course you're going to want to keep water, dirt, possums etc out.
*the rule is 48V but presumably your pack is 48V nominal and it's final voltage is over that after charging. So technically you should be doing more (stickers /labels/IPxx, etc) to make it hazardous voltage compliant but that's on paper and we are in the real world and if anyone asks it's '48V' not 'fully charged it's 53V'.
On a side note, this picture
Looks like it was taken on the set of Thomas the Tank Engine
