I purchased a deep cycle excide from Rural King for my 2000 lb wench. It works for what little I use it.
However, after buying the excide battery I purchased a battery conductivity tester which can measure CCA. My excide battery measured only 500CCA. The deep cycle battery that came with my 10k dump trailer measures 1000 CCA.
Deep cycle batteries don't give you their CCA, so unless you take something to the store to measure the batttery before you buy it, you really don't know what you're getting.
Excide also makes a very large lawn mower battery. It measure over 400 CCA. Go figure.
I rigged up a way to connect my dump trailer battery to the battery of my IH C, which I use to pull gravel out of my old gravel pit. That way my dump trailer battery is getting charged when I using the trailer. The same could be done with any wench battery. Charge it off the truck when not in use.