4.8 might need new alternator

[Chris mac]

So was driving to work Friday and got the Christmas tree on the dash. Trans malfunction, 4x4, ABS, ETC... Radio goes out but drives ok. Then goes into limp mode, so I pulled over and parked in a parking lot.
First thought is battery. So, replaced with identical one from Napa(AGM) and made it to work late, and got home ok. All lights and warning went off after new battery and I started driving.
At home I hooked up the Foxwell scanner and registered new battery and checked voltage. Took it for a drive while live scanning and voltage is around 11.5-12.0 the whole time. I have been reading up a lot on this and everything says it should be around 14 volts.
Does anyone have any input on this. Is it a new alternator I need? Maybe a voltage reg.?
Any help would be appreciated
08 X5 4.8 57k miles