Home DC charger

[acdcvw]

I've done some rudimentary searching and didn't see any reference to a home DC charger. I'm no electrician nor do I play one on T.V. so can someone explain to me why there doesn't seem to be a home DC charging option? I'm aware the home system is ac but converting ac to dc is easy enough, doesn't take any type of fancy equipment to do so.

Thanks!

 

[RonDawg]

Are you talking about DC Fast Charging? If so cost is the biggest reason, both for the chargers themselves ($15k is an often-quoted figure at MyNissanLeaf) plus the demand charges your utility will likely impose as a residential customer.

If you're talking about simple DC into the car but at regular amperage (under 40 amps), EVs were designed to take advantage of existing AC infrastructure available to homeowners, whether existing (120 volt) or relatively easy to add (240 volt).

 

[acdcvw]

Are you talking about DC Fast Charging? If so cost is the biggest reason, both for the chargers themselves ($15k is an often-quoted figure at MyNissanLeaf) plus the demand charges your utility will likely impose as a residential customer.

If you're talking about simple DC into the car but at regular amperage (under 40 amps), EVs were designed to take advantage of existing AC infrastructure available to homeowners, whether existing (120 volt) or relatively easy to add (240 volt).

Thanks for the reply

 

[miimura]

It is also easier and more efficient to rectify 3-phase AC power to DC than single phase. The commercial DC chargers are all at least 3-phase, usually 480Y277V, but there are some that are 208Y120V (120VAC above ground). My utility will not provide 3-phase to a residence.

In theory, there is no reason a commercial 240VAC DC charger could not be made. However, there is probably no consumer demand at the price point that would be required for a properly developed, tested, and listed residential DC charger.

 

[acdcvw]

It is also easier and more efficient to rectify 3-phase AC power to DC than single phase. The commercial DC chargers are all at least 3-phase, usually 480Y277V, but there are some that are 208Y120V (120VAC above ground). My utility will not provide 3-phase to a residence.

In theory, there is no reason a commercial 240VAC DC charger could not be made. However, there is probably no consumer demand at the price point that would be required for a properly developed, tested, and listed residential DC charger.

Appreciate the response.

 

[GadgetGav]

Also, why would you need it? The Tesla superchargers add about 170 miles range in 30 min and our cars only have a 90 mile pack. It would be charged in no time. That might be a neat trick, but it's a but unnecessary..!
The car already contains circuitry to rectify 240V AC into DC, so why pay for it again on your wall?

Solar PV on the other hand... That already produces DC so in theory it could be stored (Powerwall) and / or sent to the car as DC, but as it's designed to supplement / replace the utility supply it's converted into AC either with micro inverters at the panel or one big one at the breaker box. I don't know any Solar PV supplier who's selling residential DC charging.

 

[miimura]

I don't know any Solar PV supplier who's selling residential DC charging.

That's right. It's a great idea and it has been demonstrated, but it's not commercially available.

 

[acdcvw]

Electric Motor Werks, Inc the makes of the JuiceBox evse offer a residential DC charging system: http://www.emotorwerks.com/products/online-store/category/listing/17-dc-charging-systems
The price isn't all that surprising what's unfortunate is that it appears to be offered only with a CHAdeMO plug.

 

[GetOffYourGas]

Technically you have a DC Charger - in your car. All EVs have an onboard charger which converts AC to DC, and then charges the battery. Your DC inlet simply circumvents that charger, and allows for an external one. You carry one on board so that you can access the ubiquitous AC electricity. The primary reason for an external charger is speed, which was covered above.

There are people who advocate for removing the onboard charger and replacing all AC EVSEs with DC chargers. In theory, one could then get much better use out of each charger (by sharing amongst multiple cars) while simultaneously removing $2k from the cost of the car. I don't think that we are anywhere near critical mass for this approach, but you could imagine it happening in the future. I would still prefer to have at least a small onboard charger for charging on the go.