There doesn’t need to be a separate access panel. It can just be in a normal battery holder like so: https://imgur.com/a/Zur6G0x Replaceable CR1225 in Cisco 1802
Considering it’s something that generally runs 24/7 for years, it may still be a good idea to clean out dust from the device when possible. That’s also an opportunity to replace the RTC battery, assuming it’s replaceable. Oh, hey, it seems Cisco even used to provide some Li batteries until 2017.
Also, not all businesses need the networks up 24/7. There may be plenty of time for down time for maintenance.