I finally got some info direct from the horse's mouth: an Iota engineer
He confirmed that, indeed, Iota
chargers use Pulse Width Modulation (PWM). PWM is a technique which has generated a lot of excitement in the field of battery charging
and other electronic applications in the past five years or so.
You can read about it here:
This explains (to my satisfaction, at least) why Iota chargers don't need to have either battery
temperature sensors or battery type settings for flooded, AGM
, or gelled batteries.
And, I know for a fact that they work very well in keeping batteries charged, and don't cause objectionable RFI.
I've asked Iota for anything they might have in writing -- a white paper or such -- but I don't really expect anything more.