my battery light flickers on and off under acceleration and when the light starts flickering it seems like the truck starts to miss a little.
I put a new alternator and two new batteries in it this year.
light started flickering so I got out and put my meter on the battery and I have 13.8 volts engine warm and running with the headlights on.
any ideas appreciated

 

also my terminals all look like they are in good shape

 

That light is pretty much right, something's up. Have alt tested (or consider a replacement/upgrade) and triple check the plug on the back and the harness connector very closely. Battery test also, be sure to disconnect a cable so they are tested independently, a good one will cover up for the bad on if they're connected together. Don't let it go too long, charging issues can damage the fuel injection control module.

 

The voltage regulator/diodes are acting up. Pull the Alternator and have it tested at O'Reilly's. Did you buy rebuilt or new? Ford or Aftermarket?

 

Alternator, had exact same issue, intermittent, left me stranded. Get a scangauge so you can constantly see the voltage, amoung other things.