After struggling trying to use a float type hydrometer for testing the Battery Acid specific gravity and giving up from frustration due to the float always sticking to the side and not reflecting the true sg, I got a Reflectometer type. What a difference. In less than the time I tried to get 2-3 readings with the float, I accurately measured all 24 cells, and to confirm the accuracy, I repeated the test on the same cell several times and got exactly the same reading on all test. My advise, don't fool with the float or floating ball chepo units and get one of these if you really want to know what your batteries Specific gravity is.
Now I can proceed to determine when my equilization and reconditioning of my batteries is truly as good as possible.
I found that the refractometer is not totally immune to the effects of temperature so I have ordered another type of hydrometer that hopefully will provide accurate repeatable temperature compensated readings.
Midnight solar/ HydroVolt hydrometer
Will do an in depth comparison of the three systems.