Long time no post!

Long story short: My original alternator started smoking up so I replaced it with an eBay special alt. After a week of driving, the battery light starts pops up intermittently on the dash, usually when I come to a complete stop at the lights and goes away when I accelerate.

A quick test with the multimeter shows the battery at 12.8 volts (car off) and the alternator charging at 13.36 volts car on idle, lights on, at operating temp. Is this normal? or should it be towards 14 volts?

I checked all the connections and everything is tight. I didn't use dielectric grease on the connector or anything if that mattered?

 

Your numbers sound about right, but maybe a little low on the 13.36 at idle. I'd drive your local autozone/advance/auto parts chain store and let them do a charging system check. Could be one of the diodes in the regulator is bad. They can tell you if and what's wrong. For the record, I bought a new aftermarket alternator for my 2007 Ridgeline once and it was bad. A second replacement is still trucking after 3 years. Lesson: Don't always trust a new aftermarket alternator is infallible.

 

That voltage is at the very end of the acceptable level of volts at idle. I'd replace both the battery and alternator to be safe. A bad alternator can cause a good battery to become bad.