geezer wrote:
I bought a battery tender so as to maintain full charge on my
problematic rider battery. It bothers me that the male plug for the
ting is only 2-prong. Seems to me that I connect it to AC source
backwards, that it could cause charging problems. Can it?

Or am I just paranoid?

Yup, paranoid. The charger is built around a transformer that isolates
the 120 VAC power input from the DC output. Reversing the plug does not
affect the DC output in anyway.

Having a third prong would permit the (metal?) case of the charger to be
grounded. This means that an internal short in the charger would not
give you a shock. But it is just as safe to make the case out of an
insulator such as plastic and physically arrange the wiring so it cannot
chafe or break.