Using the P4400 KILL A WATT P3 I did some more research. Furthermore, I disengaged the doors from the equation all together running the door openers up and down while unscrewing any related light bulbs.
Single door / Manufacture Date 2000 / 1/2 H.P. / Chamberlain
5W Always on
480W max going up
510W max going down
Reconnecting the single door, which freely opened by hand, added approx. 20 watts more in either direction
Double door (same manufacturer as the single door) / Manufacture Date 2007 / 3/4 H.P. (assumed) / Chamberlain
6W Always on
63W max going up
34W max going down
Reconnecting the double door, it too moves freely when opening by hand, maxed around 150W when going up.
Nothing on the opener itself or 2 page owner’s manual would indicate H.P.
I will indicate that this opener is considered a Whisper Drive and is belt driven vs the older opener that is chain driven.
*All max readings last for a brief period of time. I was dong this test by myself and thus was pressing the button on the wall and quickly running over and looking up at the Kill A Watt for all readings. I did not have handheld remotes for this test and missed the first couple seconds of each reading.
Both doors travel at similar speeds. But to be completely honest, the newer one on the double door is slightly faster. The double door is also the one that is used daily for our two vehicles. The single door maybe a few times a week for lawn mowing or to remove a bicycle.