If the brain of the hybrid is its network of computers, sensors and software, the heart must consist of electric power and engine (two chambers of the heart, if you will). The batteries, especially the main propulsion one, fascinate me but are beyond my depth, as an amateur auto mechanic. So I was pleased to find an internet site sponsored by a Canadian company, CADEX, that shares technical information for all of us. Its copywrite rules prevent direct quotations, but I recommend it for many of us who are interested in such subjects as battery design, maintenance, capacity, recharge, renewal after failure, etc. Here's the link: http://www.cadex.com If anyone is highly qualified to critique its validity, opinions would be appreciated.