idle stop is older model , ene-charge is newer model, ... they are not hybrid. the latest model which is S-ene-charge is only a little bit hybrid.
both idle stop / ene-charge has same functions i.e. idle-stop and battery charging on deceleration. both have extra lithium ion battery (2012+ models) below passenger seat.
the later model labelled 'ene-charge' they have 'improved' the fuel economy and the battery charging functionality as in it charges the battery more efficiently and battery used in idle-stop mode is also better.
you can go throught this link to read more : http://www.globalsuzuki.com/corporate/environmental/green_technology/