One reason I haven't been posting much lately is that I've been trying to get my batteries charged. When one started blinking, I stopped charging, measured all the batteries, and drained them a bit: about 1A for 10 or 15 minutes, so 0.25AH. I figured I'd be draining the full one and allowing everybody to get a good charge when I started again.
A post on the EVDL told me I was killing my batteries again by draining them before they were full.
Now I've been charging at 0.5A - 1A for more than a week. Whenever the voltage stays constant for 8 or 10 hours, I turn off the car for a day or so and start again. There has been progress: now 7 batteries are blinking, one has charged high enough to turn off its red 'undervoltage' light but doesn't blink (that one really concerns me), and my voltage has stabilized at 167.0 while charging.
So I turned the charger off. This morning the pack read 143.0V. While that may sound close to fully charged, it really ought to be reading about 156V.
My plan is to let hit them with as much current as I can until the first one starts to blink. To prevent gassing, I'll then turn down the current to 1A. I hope this shakes loose whatever sulphation is causing my problem.
Already the EVDL has told me that my charging thus far has been incorrect. This time it was no less a personage than Lee Hart.
His instructions seem to indicate that I should continue more or less on my current course: he recommends a 4A charge, to 116% capacity, followed by discharge, repeated until capacity is recovered as much as possible. I'll have to read it again to make sure I understand what he's saying.
He also advocates weighing the batteries to see if they've been gassing, and drilling holes to refill them with distilled water. That may be a little more than I'm ready to attempt. Still, at more than $100 per battery, I'll probably give it a try if I can't get them charged any other way.
I really wish I could finish this and take the car to work, already.