how to tell if my battery is getting weak.

When I bought my car, I thought there was about 130k on this car turns out it's more like 170k - 175k in southern California miles. which means a lot of heat exposure. I'm thinking of buying a few batteries off ebay from a source in new jersey, I suspect that the battery cells from this guys advertised at 7.6 to 8.12 volts are in better shape than any of my cells I figure if I buy 8 or 9 cells I can place my weakest cells.
Now I was wondering I've been reading a little bit on these forums and I have dealt a little bit with NiMH battery packs in the past. at 0.1 C capacity they should reach about 1.44V at 0.5C it's more like 1.48V and at 1C it's a peak of like 1.53 to 1.55V per cell so a 6 cell Battery should be fully charged in like 14 hours from empty at 0.65 Ah of a charge at it shod peak at 8.64 volts. but I have been reading different values on the forums here.
would like to find some solid data.
A. what is the actual capacity of the NiMH batteries originally.
B. I was thinking of setting up a bank of chargers to pulse charge the cells and then drain to equalize them. What are some good Specs to use.
C. What are some good ways of determining which cells are the weakest ones?
D. where is that test point to measure the overall voltage of the hybrid battery?
I don't have a warning yet, but the gas mileage is under 40mpg I am pretty sure hoping to get this up long term.
terramir
PS: what was up with the outage this morning