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Chevy Volt Home Charging & Grants

Chevy Volt 240V Charging Station

Back in July I went to Plug in 2010, a techonology conference for plug in vehicle manufacturers, parts suppliers and of course plug in station providers.  While the Volt will come with a 120 v Charging Cord, (also known a level 1 charging connection)  Volt buyers can optionally install a level 2 charging station at home.  There are many companies out there that provide both home and public charging stations, and it is worthy to note that there are significant subsidies in place for the prospective Volt buyer depending on where you live.

Before we mention the subsidies, it is worthwhile to note the wiring requirements needed for both Level 1 and Level 2 charging at home.  As I’ve already placed an order for a Volt, I’ve had one call from Chevrolet mentioning that in a month or so a Volt specialist will contact me to educate about the ordering process, and also walk through home charging – so level 2 charging is something they are taking seriously. 

The difference between Level 1 and Level 2 charging is very straightforward, it designates the amount of power that will be available to charge you batteries.  With a level 1 charger it can take 8-9 hours to charge a fully depleted Volt batter, with a level 2 charger it will only take 3 hours. 

So level 2 charging makes a lot of sense for people who make multiple trips in the day and have an opportunity to charge at home. 

Below is an image of the charge equipment available for the Volt

GM is First Automaker to Reveal New Charging Equipment

Typical Level 1 chargers are rated to draw 16 amps at 120v – at perfect efficiency this is a maximum power rate of 1.9Kw.  See  http://www.coulombtech.com/products-charging-stations.php  Of course, there are charging inefficiencies and also the Volt will siphon off some of this power to condition the battery.  Additionally, the 16 amp rating is what the cables should be rated for, which doesn’t neccesarily mean it’ll take all 16 amps continously. clarification: The Volt’s Level 1 charging package comes with software / controls to draw either 8 or 12 amps depends on the type of circuit it detects, meaning you can use a 15 amp 120v circuit – Thanks Jeff! Since we know that the Volt has 8 Kw*h available and it takes roughly 8-9 hours to charge, we’d expect 1Kw to be used on average for actual charging.

Compare this to a level 2 charger which requires a permanent hookup per electrical code requirements (you can’t just use your dryer plug)  Which is designed to use a 240v circuit at 30 amps.  This means a maximum power draw of 7.2 Kw.  Knowing of course that they’ve mentioned it will take about 3 hours to charge a 8 Kw*h pack, we can see that the charge circuit is designed to draw on average 2.6 Kw

If you are in the market for a Volt or new plug in vehicle, check for local subsidies for levl 2 charging installation.  For example – here in San Francisco, the Bay Area Air Quality Management board has apportioned $5 million to subsidize home charger installations (and public ones as well)  3000 home chargers are available. 

Of course, before you can put one of these in you’ll need to make sure that your home circuits can take the additional load.

9 Responses to “Chevy Volt Home Charging & Grants”

  1. Jeff N says:

    The Volt’s 120V charge rate is designed to be safe for circuits designed for 15A. Although the wall plug and circuit is rated for 15A or 1800 Watts, individual appliances are normally designed to draw not much more than 80% of that.

    According to autoblog.com, the Chevrolet 120V charge cord has a switch to select between 12A (1440 Watt) and 8A (960 Watt) in case you have other low power devices using another wall plug on the same circuit breaker.

    With the 240V charge cord, I believe the battery charging system built into the car is self-limited to roughly around half the usual 240V 30A home circuit rating.

    The Nissan Leaf on-board battery charging system has a similarly limited capability when charging from 240V AC. Nissan has said this is because a charge rate closer to 30A would raise the cost of the charger circuitry on the car.



  2. Jeff N says:

    Another good choice for J1772 charging equipment in the near future may be Leviton which is a major provider of traditional electric wiring components. They generally have good quality parts at good prices and they had an exhibit display at the recent Plugin 2010 conference in San Jose.

    They have a dedicated website at http://evrgreenchargers.com.

  3. ScottR says:

    I know that this article is a bit out of date, so a further clarification to Level 2 charging equipment (this page is coming up pretty high in Google when searching for this info):

    Although the amperage requirements for L2 charging stations differ between models and mfrs., the “standard” Chevy Volt L2 charging station, the Voltec from SPX, requires a 20A 240V circuit, and will draw a maximum of 15A. (Per the specs on the mfr.’s site: https://www.homecharging.spx.com/volt/pdf/GM10-463.pdf ).

    I’ve seen a spec of 30A @ 240V being thrown around a lot regarding the Volt, but that’s simply not true of all charging stations.

  4. Mel Presswood, P.E. says:

    Most regulatory agency inspectors are allowing 20-ampere circuit breakers instead of 15-ampere circuit protection, and they are plugging cord sets rated at no more than 15-amperes (as evidenced by the NEMA 5-15 plug) into branch circuit protection of 20-amperes (i.e. a little over 70% more power capability for a purely resistive circuit). Appears to me everybody is ignoring the significance of NEMA Article 110.3(B), 240.5(B)(1), and 240.5(B)(3)?

  5. William Neal says:

    Why can’t the Chevy Volt charge it’s own batterys as it is rolling on the road ?

  6. Rchi says:

    @willie neal: because that was never the inteded function of the backup generator and kind of wasteful all things considered

  7. kny says:

    I am building a new home and want to wire the garage for a Level 2 charger.

    Am I correct in that I need a 240V, 20A dedicated circuit? And 12/2 wire?

    Thank you.

    • jefro says:

      If you have to ask then you should not attempt to install a circuit.

      “Am I correct in that I need a 240V, 20A dedicated circuit? And 12/2 wire?”

      No, you need to use tools to determine load, length and other factors such as the local ordinances that may affect the installation. A licensed master electrician working with your building department would offer the most safe installation.

      Not to mention you would usually require /3 or /4 wire.

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