Though the voltage of hand-held battery powered portable tools has increased, I have an older drill/driver from the 1980's (9.6 volts) and a couple of Milwaukee drills at 12 volts. They are still relatively safe from shock hazard v.s. 110 volt cord operated power tools, even the double insulated tools, IMO. Most, in the truck tools, are now 18 volt, I have seen some 20+ volt tools. Every DeWalt portable battery powered tool, that I have, has an additional battery, charging, while using the other battery. The additional battery fits in the carrying case provided with the tool. Note that old batteries should be disposed of properly.
I've seen construction site power supplies where there was not enough 110 volt outlets to plug-in all the battery chargers. Another problems was identifying your batteries and charger.
Another point on those construction sites, the lift machines are 24 volt DC requiring usually (4) 6 volt deep cycle batteries. An overnight charge will usually work for all of the next day, if you can get your employees to plug-it-in at the end of the day. There is not a lot of step ladders on commercial jobs, IMO. I've seen as may as five hoist, usually one for each trade involved. Scissors/Lift battery chargers are contained in the unit and can draw a fair amount of current @ 110 volts. We have had issues on construction sites where there was not enough 110 volt 20 amp circuits at the end of the day to plug-in all the hoist at one time.