Well I tested the alternator output with the PC on, music at full blast, GPS signal booster engaged, OBDII reader active, rear and side mirror defrosters on, cruise on, A/C on, fan on high, and 35W bi-xenon brights on and it says 13.8/13.9V and 73%, but that percentage may or not mean anything because the manual says that's "relative output compared to 'normal' alternators." Of course the manual doesn't tell you the number it's using as normal, hence why it's more or less useless.

So maybe my alternator is on the way out?