Dave,
You certainly were very technical in your discussion. I would like to remind members of FIRST that "wet" cell batteries of the type in you cars are nominally 13.8 volts when fully charged or 2.3 volts per cell. The manufacturers spec on our sealed, lead acid, battery or SLA, is 13 volts or 2.16 volts per cell. Different battery types all have different cell voltage, 1.25 volts for NiCad and nickle metal hydride, 3.6 volts for lithium, 1.5 volts for alkaline, etc. Now should you use a voltmeter to measure the terminal voltage of your car battery while it was charging in your car you may find the voltage regulator is putting out 14.2-14.5 volts which is a little high for our battery but fine for the "wet cell". Therefore any battery charger which puts out 18 volts with a battery connected would, in my opinion, be ready for the circular file. One that puts out both 18 volts and damages batteries has crossed over to junk status and should be treated as such.
I would like to remind everyone that the chargers supplied by FIRST or equivalent are the only ones that are legal for use in competition.
C20 When recharging Kit batteries, you may use the charger provided by FIRST or one
with equivalent charging characteristics.
(I like the new 6 amp smart charger but still use the 4 amp charger First had supplied for years.) Using other chargers, auto battery chargers included, runs the risk of battery leaks, battery damage, and injury. They put team members at risk as well as others that might be close by. If detected in the pits, I would expect a DQ on such use. Don't take safety lightly, especially in the pits.
Here is the official spec sheet on the battery...
http://www2.usfirst.org/2003comp/Specs/Exide.pdf