Hyundai i10 "Blue" model in the UK has an "Alternator Management System" which seems to monitor when the engine is under load (e.g. climbing hills, accelerating hard) and reduces the demand from the Alternator from the engine. It also increases it when it can such as in gear downhill coasting etc.
Linky
Here is a pic from the brochure
The "Blue" (named after the VW/Merc "Blue" eco technology - well they don't want to give the Green Party any credit do they ?) failed for me because it's too expensive for what it is.