The load management controller on the charging system at work. This is a screenshot from the web page for the controller.
Interesting. It certainly does not do that with my 120 charger at home. Pretty much full blast until the last 15 minutes, then it drops to about 1/2 the full rate. Of course, it's charging at about 1/3 the 208 rate to begin with, so less taper would be required. I just bought a 240 cord but it's not hooked up yet. I'll be interested to see what happens.
