"Located in low overhead Monroe, WA"
Are you referring to flight ceilings here (bg). I grew up in Renton.
There are many reasons for disconnecting the battery, most are to prevent short circuit risks while disassembling. Similar to flipping the breaker at home to work on the outlet or light. When trying to prevent spike voltages the battery is an ally
Bosch Master, ASE Master, L1
33 years MB technician