3G Alternator on \'88 Mustang

I installed a salvage yard '95 Mustang 3G 130 Amp alternator on my '88 GT using info on the web sites referenced in previous 3G alternator uprades on FordMuscle. Used a 4 AWG charging wire with 150 Amp fuse to the starter relay.

It is charging the battery at 15.1 volts, isn't that bad for the battery?

I removed it and installed an alt. from a '96 mustang same thing.

Took the alt. and had it tested, they said it should output 15V which it did on their machine. Is 15V going to harm the car and or battery? Don't want to blow up the battery.
[addsig]

Doesn't sound like a problem to me. It is definately charging well. It shouldn't hurt the car, and I dont think it will hurt the battery.
[addsig]

I called Mark Hamilton at MAD Electrical he thought the problem was the alternator had not warmed up (the regulator should have temperature compensation).

I ran the engine with all electrical accessories on except the wipers, the voltage went down to 13.2 at idle when the A/C compressor kicked in.

I assume the standard load of the 5.0 Mustang was not enough to drop the voltage on these high power alternators. I plan to fix that by adding an electric cooling fan.
[addsig]