A month ago I've received my Chevy Volt components (battery, charger, inverter). I'm going to slowly start a thread on each one of those components, to show how they can be reused for DIY (I've posted some info how to use the battery relays and control in the Chevy Volt battery thread already)
Chevy Volt charger:
According to this study http://www1.eere.energy.gov/vehicles...rd_charger.pdf
You can expect 3.3kW power from 240V socket and 1.2kW from 120V socket.
Strangely enough, this module also charges 12V battery (0.4kW), but only during the charging period. For alternator replacement, Chevy uses a dedicated DC/DC converter located in the rear trunk.
Charger is composed of three modules:
- Main control board (AC->DC, capacitors, two processors, one mainly for data transfer and high-level planning, other one is for low level DC/DC switching and control)
- PFC section (the board with less magnetic cores)
- DC/DC converter (mounted on the bottom)
From external, there are very few "wires" to control this thing. You will find out that except for the usual (ignition start, 12V, HV cabling), everything is CAN controlled, so there is no way how anyone could reverse engineer the protocol on this thing without having an access to working Chevy Volt and its CAN bus.
Very unusual thing about this device is the use of embedded coils and magnetics - PCB acts as a coil, with ferrite cores clamped through from both sides. Also extensive use of heat-conductive glue/silicon. The whole thing is basically glued on a cold plate (watercooling). This explains how can they get away with such compact cores - a lot of thinking went into the thermal design of this thing.
After playing with this charger for a weekend, I'm pretty sure about how switching elements are controlled and which lines have to be controlled in which order. Protective PCB coating layer is making this rather annoying process.
It is definitely possible to reverse engineer enough of it to replace all control systems with a simple microcontroller. I'm not sure if making this work as open source is worth the time, so that's when you guys come in. Do you thing this is worth the effort?
If someone could capture data on the CAN bus - car standing still, charging cable inserted and then later charging terminated), I might be able to come up with a simple way how to use this thing stand alone without HW modifications. Otherwise we are looking on board-level changes/hacks.