[Elecraft] Batteries, batteries, batteries

[Vic K2VCO]

My brother-in-law just gave me a large box containing literally hundreds of what he says 
are recharageable batteries. That is all he knows about them. They are in sets of three in 
series, AAA size, with solderable tabs. I suspect they are nicads, but don't know. NOTHING 
is written on them. They are green, for all that means.

Can anyone guess what they might be or suggest a way to find out? Could I put them in 
series/parallel to make a battery pack for my K2? Does anyone want some?

Or should I be looking for a way to dispose of them (I'm sure they count as hazardous waste)?
-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/