I picked this rusty old thing up, as-is, from someone for $5... I
figured it had at least that much worth of copper in it. After sitting
in my cellar for a few years, I decided to drag it out to deal with a
chronically dead battery.
The first picture is the before picture of the wires... yikes, bare
copper. That's really good quality stranded copper though, so I did up
the "electrical tape special"... it took two rolls, see center picture
for the finished product.
Surprisingly, it works like a charm. 6, 12, or 24V battery settings, as
well as slow automatic or fast manual charge. The gauge seems to work
as well. I assume this model would have been owned by a mechanic or an
auto parts store back in the day.
https://postimg.cc/gallery/Px9X0sj
The only thing that I cannot figure out; what is the "polarity protector
safety light"? It was lit the whole time that I charged the battery. I
had the "red" clamp on the positive, and the "green" clamp on the
negative. The battery charged fine, so I don't know what was up with
that. The body was not otherwise marked which terminal was which.