Speaking of batteries

How does one go about testing to see if a second hand set of Ryobi
18v batteries are still "good"?
These are the green ones, I am not sure right now what type they
are (Lithium Ion, Ni-Cad, Auto-Cad, Alkaline, or Iron-Pyrite) but I am
not sure if they need replacing or not. I got them, and the charger,
and three tools at a thrift shop. "Guarenanteed not to rip, rot, rust
bust or throw dust - thirty feet or thirty seconds provided the
customer does not fool with them." {"Did you charge the batteries?"
Of course I charged the batteries!
"I told you not to fool with them!"

(OTOH, could be that I was over expecting how much use I could get
of a pair in the circ-saw cutting oak pallets.)

But anyway, testing procedures for batteries?

Or just bite the wax tadpole and get replacements?

tschus
pyotr
--
pyotr Filipivich
"Bother," said Pooh, "Eeyore, ready two photon torpedoes and
lock phasers on the Heffalump. Piglet, meet me in transporter
room three. Christopher Robin, you have the bridge."