[289fia_cobra]

I took my FFR to work and to my nephews 'car show' at EA today.
On the way home from work, I noticed my volt meter was under 12V. Normally on any given time, it's between 12 and 14 so call it 13V.

No matter how high I revved, it remained below 12V. I made it home but now to figure out if it's the alternator/regulator or battery.

The alternator is a 100A Power Master single wire so the voltage reg. is built inside.

The batter is a red Otima I've had since early 2006 so it's over 7 years old now.

What's a good way to check the alternator and should I just replace the Optima due to it's age or keep it longer???

TIA