I did some test welds with my new cable setup. Some improvement- with difficulty I can now use the 7018 rods...which as MikeN suggested, don't have slag inclusions. With the 7018, the arc keeps stopping, but I can restart and work back to the still hot old puddle, without pausing for chipping, and I still see no slag inclusion. As Mike said, it 7018 works way better (arc is steadier) pushing the rod instead of dragging it. Thanks, Mike!
I measured the amps and volts, recorded the meters via camera on tripod while welding. I seem to be in the 85-100 amp range most of the time on 3/32 rods, but some blips to 110 and 60. I was using a digital clamp on amp meter so difficult to see the real picture. (Digital curse.) I put the meter between the battery and the choke in hopes of seeing the smoother, average current.
I tried 6011 rods- they are terrible, slag inclusions, bubbles. They are the AC version of the 6010 rods, which I have on order because no one stocks them locally.
I tried a 6013 - 1/8" rod. It seems to work fine, more metal for the same flux, no harder to work with. I didn't check the amperage on that, and I should. Given the problem with slag inclusions with 6013, I think I'm better off getting the hang of the 7018 rods.
I had some trouble seeing with my new welding helmet filter; it's supposedly a 9 when "on". It's a bit too dark for me, and then I realized that my cataracts are probably adding to the problem. An old T shirt taped to the helmet to get rid of back lighting helped, but light is still coming up from underneath, and it's still so dark I can't see well. Plan C- maybe some welding googles, with a 6 filter???
Edit: Current on the 1/8 6013 is about the same, 80-110. Voltage drop on the choke at 100a is 0.4V, as expected for 16 feet, 6 strand 12 awg.
I must drag/work the rods very close, right on the flux edge, can't pull back at all. I will try 36V tomorrow for comparison. Oh, for a 6v battery!