Kia Rio Starter Trouble?

I think my friends car needs a new starter.

Scotty,2009 Kia Rio,Recent cold snap in Ohio,down to 0 degrees F at night.Friend tells me his car seem like it needs a new battery.I checked it in the afternoon at 15 degrees F.It cranked over at a slow.steady speed and fired up with no trouble ( in my opinion normal slow cranking due to the cold ) Looked like original battery ( said Kia on it ).My friend bought a new battery.He then tells me it still seems to be starting funny.I used my multimeter,12.3 volts in the battery with engine off,right around 14 volts with engine running and electrical accesories on.I told him I think he's just interpreting normal slow-cold weather cranking as a problem.I went over there early in the morning to start the car after it sat overnight.It was 3 degrees F. and that is when I saw an issue.For about one second the car cranked normally,then all of a sudden the cranking speed dropped dramatically very briefly then sped up to normal again and the engine fired up normally.At that point I told him I think he needs to replace the starter.I tried to capture it on video,but only a half a second got filmed because of insufficient memory on my sd card.I'm glad you like what you're doing,people need you! Thanks.

it's charging up right, but to load test a battery it's more than just voltage, see this video. either battery is weak or starter is weak for slow cranking at cold.