It's likely to be one of the heaviest things in the area, so low is good. It also will require battery replacement every few years, so try not to bury it too deeply, or put it in a location that requires a huge amount of rearranging to access. It does create some heat, but as long as it's got a little air exposure it'll be fine.
Try to manage it so the batteries are never depleted too far, or you will be replacing batteries sooner. As a rule of thumb, I like to attempt never to go below 50% charge, which means if things don't go as planned you have a healthy margin before things get bad.
Keep in mind the recharge rate is likely around 10 or more to 1, meaning if you discharge for 5 minutes it's probably going to take close to an hour to fully recover. During discharge and recharge it will get significantly warmer. The long recharge is another reason to not deeply discharge, it would suck to go to all the trouble of setting up a good battery backup and have 2 back to back outages negate all your effort with a dirty shutdown.
The batteries are SLA, sealed lead acid, so sort of like a car battery in some ways.