But...
The 'rule of thumb' is RPMs per volt, so that motor was not a good choice.
"label on the motor says" it needs about 600 RPMs to hit charging voltage for a 12V system.
And I never had good results with that rule of thumb, always needing more RPMs.
Given your numbers it needs the rule of thumb, and my 'more than that', it needs 'over' 17% more RPMs than 600, or 705RPMs before it will make a milliamp into a 12V system.

The blades look and sound very slow. More like drag blades.
Make some wood blades a little shorter than those. Even a first decent try should do much better.

Forgoing the loss and other issues with gearing...
"The one I REALLY want to see working" needs 1100RPMs or more.

"The other motor is similar to the above, but it's a 120dcv motor rated to spin 13,000rpm."
Not good.  13,000/120=108. That X 15V = 1625 RPMs before any chance of filling a battery, and that is before my 'more than that' fudge factor.
Don't do it.

Never give up, never surrender!

But perhaps at times we must fall back and re-group.

 I started to mention a few things, but it sounded to negative when I read back over it so I deleted it. Basically, rpms for motors too high, blades not working fast enough.
Probably looking at large ratio to belt drive them fast enough and slipping belts a large problem perhaps.

"and the motor will be fitted with a 1" pully."

????? I just plain don't think that 1" pully will work at all, I could be wrong but that's my thought!!! It may be fine free spinning with no load, but will slip "like a wet seal on ice" under load.
.
nothing to lose

Yeah the blades are crappy.  What I did was a combination of having nothing better handy to use and wanting to try out my new plasma cutter.  A friend of mine was at my house earlier and told me it was reading 6.1dcv...for flat rough cut blades they sure do boogy.  If I'm not mistaken that's right around 285rpm.  They're somewhat flimsy, though, and one blade's about 22 grams heavier than the others, and I knew that going into it so I wasn't really expecting much.  I was suprised with what I got, though.

Tomorrow I'm going to the lumber yard to pick up some 2X6 stuff to make an 8ft prop (I'll go into it in a minute) and I'll probably just get a 8ft 1X6 to carve up a new set of blades.  I just hate carving, though...but it'll give me an excuse to make a good draw-knife...score!  I'm going to try a 5ft prop on it and if she doesn't graze the 400rpm mark then I'll shave it down some.

As for the 36v motor...it's a badass motor...I've at least got to try.  I built a chassis for it...a piece of 3/8" thick 3X4 angle iron with a blower fan axle.  The prop and pully will mount on one end, and a cradle is above it for the motor to be strapped to.  I'm using a 2" pully on the motor, though, because it's got a flywheel.  Of course the effort may be misguided, but I like the idea of a little more rotating mass in our inviroment.  I've also build the chassis to mount on bare 2 3/8 tubing like the little one pictured above, but there's no bearing.  I've greased it up pretty good but I don't want something that'll flop around like the other's I've made.  At any rate, with an 11/2 setup I'll only need to turn 475rpm to have an interesting output.

What about a 480dcv motor rated at 1150rpm?  Weighs about 400lbs so I have no idea where I'd put it but I can get one.  I think the label actually says 12,000 watts...hard to say, it's in chinese. :D

If you can't twist them to lower the pitch at the tip, I believe tappering down to an inch or so wide at the tip will help.

Also, make sure they are balanced before showing them the wind. I once flew some unbalanced blades just to see how they would do. Scared the hell out of me when the vibration started.

Good luck.

 the rough cut that seems to have been made, along the edges of the blade strips, gives me concern, in that, accelerated fatigue could set in, and unbalenced radial forces could cause sheer in a relatively short period of time(at the bolts) with any type of continious operation. Wood surely is more durable.

 The other end of the spectrim states, that one should not mess with road signs. Ive heard so many bad storys about old country roads and accidents that occured at night time.

Just to assure everyone, the sign was acquired legally...well sort of legally.  I jumped a colvert one night and took out this stop sign...mangled the pole but the sign was in perfect condition.  Being the good semaritan I am I notified the county and was promptly fined $354 for the sign...so I paid and took the sign I bought from them with me.

With these blades I can twist them, but it won't be even, which would cause an imbalance once moving.  I've built a set of wooden blades, though, and I'm not sure how to twist them.  I'll worry about a twist, though, after I start casting blades when I get into larger projects...it'll be simple to be consistant if all the blades come from a single mold.