From what I have seen, the first thing worth checking is whether the recycler is actually certified, since R2 certification tends to be the practical marker that materials are handled properly instead of ending up in a landfill or waterway. The reason it matters is that batteries carry lead, zinc, nickel cadmium, sulfuric acid, mercury and lithium, and those are not things you want leaking anywhere. The second thing is sorting by chemistry, which in most cases is either required or simply best practice, because recovery processes differ. Lithium ion tool batteries are not necessarily treated the same way as lithium ion cells out of phones even though the chemistry looks similar on paper. If you want the details on which types get accepted and what the handling side looks like, here is the link and you can compare it against your own volumes. What I would look at beyond the list of accepted types is the logistics side, meaning insulating and packaging, proper labeling, storage containers and whether they handle pickup and transportation themselves. For anything larger like UPS systems or EV packs, on site teardown and deinstallation become the real question rather than the recycling itself. I would not assume any single provider fits every situation, so it makes sense to check compliance requirements for your own region first and work backwards from there.