Here's a street-tossed battery power backup system, that I picked up solely to take pics of the horror.
They appear to have been in a basement or something, where the sump pump failed. Ie they were immersed in dirty water for quite a while. Even from the outside looking like complete writeoffs. Probably not even any salvageable components.
Sure enough... after breaking open the case with an angle grinder, due to rusted-in screws... yuk.
Sad.