I'm gonna tell ya..I have spent the last 2 weeks on a rotation doing Power Supply Maintenance that has sucked! We use what is called Siemens tester vs a load test on batteries and they changed the value this year by 100. Last year we changed batteries at a value of 700 (+- 10% per battery/per string) This year that value went up to 800 and we have literally changed a ton of batteries every day. Most nodes typically have 1-5 power supplies( and let's just say we have sh!t ton of nodes!). They have DC generators that charge these batteries in the event of an outage and those either run on LPG piped in from the local gas company or have yet another cabinet that holds two propane bottles. We have 120 VAC /36VDC volt power supplies that hold 6 batteries per cabinet, 240 VAC / 48 volt DC that use 4 batteries and those with no generator for standby have 8 battery strings wired in series. Most of those are aerial cabinets with trays that slide out. What makes this one suck is the fact my bucket will only lift 2 of those batteries, myself and tools to work and it moves VERY slow with that kind of weight.
Our maintenance includes oil and filter changes, battery changes as needed ( with the specs we now have it becomes almost every battery) and clearing all alarms while on site. We are also required to change these generators when they won't start for whatever reason.
At this point let me add the area I have been working is a somewhat exclusive area so everything is hidden and of course back lot out of site which makes all this work just that more time consuming and hard moving batteries and equipment to them!
Each one of these units also include a DOCSIS 3 modem that reports the status of each battery (voltage), generator status ( run status ) gas hazards, water intrusion and pad shear which also have to be tested at each visit.
All this to say I don't mind the work but it is one hellva work out every day and after 2 weeks I'm more than happy to pass the torch to the next crew!
Below is similar to what we use but our battery cabinets are much bigger. The gen and APU cabinet is pretty standard.