Streamlight Stinger XL

I bought this light in 2008. I noticed the run times were not that great within 6 months. Well, after a couple years the battery was crap. I sent it back and they told me the problem was in the tailcap.
So i just ordered 2 new streamlight cells off ebay for $10 shipped.
I wonder what cells these are? And what is their capacity?
For its size and weight this light is not even half that of my solarforce l2m!
I would love to convert it to take P60 dropins.
I have given this light to my wife for house duty.
Anyone here know anything about these?

My Stinger batteries are 3 subC NiCd cells in series, so 3.6V nominal and 1600 mAh I think.

Thanks for the reply

5 inch, Ni-Cad battery stick, 3.6 Volt, 1.8 amp hour, sub-C, rechargeable up to 1,000 times.