Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > BMW i3 / i8 / ActiveE

BMW i3 / i8 / ActiveE
Are you excited about the upcoming BMW i3 or i8? Interested in learning more about the BMW ActiveE? This is the place for you!

Reply
 
Thread Tools Display Modes
  #1  
Old 08-21-2014, 07:55 PM
mattycb mattycb is offline
i3 Driver
Location: Naperville, IL
 
Join Date: Apr 2014
Posts: 25
Mein Auto: BMW i3
DC charging at home?

Did a quick search and didn't see this question answered elsewhere. If I missed it, my apologies.

Is there any option to install a DC charger at home? There are no public DC charging stations in my general vicinity (outside Chicago). I know the level 2 charging stations can be installed at home but I don't see anything about DC from a cursory Google search.

Any ideas?
__________________
Matt
Vroom vroom
Reply With Quote
Advertisement
  #2  
Old 08-22-2014, 03:58 PM
Boatguy54 Boatguy54 is offline
Registered User
Location: San Francisco
 
Join Date: Aug 2014
Posts: 28
Mein Auto: i3 on order, Mercedes E
I suspect it would be fairly expensive as you'd need to have the rectifiers that convert AC to DC in your home charger and those generate some heat which must be dissipated. A regular EVSE is just a glorified switch with some logic to manage the control signals between the car and the EVSE. A DC charger is actually transforming the electricity.

For an i3 I think the advantages would be minimal, but maybe I don't understand your need.

What prompts the interest in a DC charger?
Reply With Quote
  #3  
Old 08-22-2014, 04:53 PM
Boatguy54 Boatguy54 is offline
Registered User
Location: San Francisco
 
Join Date: Aug 2014
Posts: 28
Mein Auto: i3 on order, Mercedes E
Here is a DC charger for home use: Electric Motor Werks
Reply With Quote
  #4  
Old 08-23-2014, 12:06 AM
mattycb mattycb is offline
i3 Driver
Location: Naperville, IL
 
Join Date: Apr 2014
Posts: 25
Mein Auto: BMW i3
Quote:
Originally Posted by Boatguy54 View Post
Here is a DC charger for home use: Electric Motor Werks
Thanks Boatguy.

The reason I asked is that the i3 charges to about 80% from empty in 30 mins on a DC charge (provided the i3 is equipped with the DC fast charge feature which mine is).

Thanks again for the link. I'll check it out.

P.S. You're blessed because I believe California is one of the only states in which BMW is rolling out DC charging stations.
__________________
Matt
Vroom vroom

Last edited by mattycb; 08-23-2014 at 12:08 AM. Reason: I forgot to say something
Reply With Quote
  #5  
Old 08-23-2014, 08:13 AM
ktagly2 ktagly2 is offline
Registered User
Location: Worthington, OH
 
Join Date: Mar 2014
Posts: 21
Mein Auto: 2014 BMW 328i xDrive
Be careful, BMW has hinted to the fact that regularly charging on a DC Fast Charge could damage the battery. Although I'm sure if you're leasing that won't matter...
Reply With Quote
  #6  
Old 08-23-2014, 09:20 AM
Boatguy54 Boatguy54 is offline
Registered User
Location: San Francisco
 
Join Date: Aug 2014
Posts: 28
Mein Auto: i3 on order, Mercedes E
Quote:
Originally Posted by ktagly2 View Post
Be careful, BMW has hinted to the fact that regularly charging on a DC Fast Charge could damage the battery. Although I'm sure if you're leasing that won't matter...
Could you please direct us to where/when they've made those comments?
Reply With Quote
  #7  
Old 08-27-2014, 10:27 AM
jimmsters jimmsters is offline
Registered User
 
Join Date: Aug 2014
Posts: 1
Mein Auto:
When BMW gets more in North America, it will be a $6,500 option not including installation.


Sent from BimmerApp mobile app
Reply With Quote
  #8  
Old 08-27-2014, 01:21 PM
Boatguy54 Boatguy54 is offline
Registered User
Location: San Francisco
 
Join Date: Aug 2014
Posts: 28
Mein Auto: i3 on order, Mercedes E
Quote:
Originally Posted by jimmsters View Post
When BMW gets more in North America, it will be a $6,500 option not including installation.
Sorry I'm missing the context on this. What will be a $6,500 option?
Reply With Quote
  #9  
Old 09-01-2014, 05:34 PM
bimmer_fam's Avatar
bimmer_fam bimmer_fam is offline
Officially Welcomed to the 'Fest
Location: San Francisco
 
Join Date: Apr 2007
Posts: 2,023
Mein Auto: '13 328i, '13 Chevy Volt
Just curious, why would you need DC fast charging at home? It's just not practical from infrastructure cost perspective IMO (besides the cost of the actual station, you most likely would need new service to your residence to provide the Amps necessary to use the DC fast charger). L2 home/work charger should do the trick in 90% of scenarios, plus you can cover another good percentage with public stations, and don't you get a "rental" ICE powered car use from BMW with i3 deal?
__________________
Chevy Volt (600+ MPG to date)
MY2013 328i (wife's new ride)
Retired:
ED2010 - MY11 328i SpaceGray/ChestnutBrwn, Premium, 6MT 05/06/10, re-delivered 07/24/2010
2010 Audi A4 Quattro
ED2007 - MY07 328i SparklingGraphite/Blk, ZSP, 6MT, 6FL 06/01/07, re-delivered 07/23/07
2007 X3si
2004 325i
Reply With Quote
  #10  
Old 09-21-2014, 01:27 PM
bayarea2007 bayarea2007 is offline
Registered User
Location: CA
 
Join Date: May 2010
Posts: 27
Mein Auto: 2009 335d; 2014 i3
anyone knows the power efficiency comparison between DC, L2, and L1 charging methods?
Reply With Quote
  #11  
Old 09-21-2014, 01:35 PM
Boatguy54 Boatguy54 is offline
Registered User
Location: San Francisco
 
Join Date: Aug 2014
Posts: 28
Mein Auto: i3 on order, Mercedes E
What do you mean by efficiency?

Converting from AC to DC is not 100% efficient whether it's done inside the car (i.e., L1 or L2) or outside the car (DC Fast). Really specific efficiency is going to be a function of the design of the converter. They aren't too sophisticated, really just a big solid state rectifier.

In terms of how much total energy is taken from the power grid to charge the battery I doubt there is a material difference between the three methods and all will be in the range of 80-90% efficient.
Reply With Quote
  #12  
Old 09-21-2014, 02:02 PM
bayarea2007 bayarea2007 is offline
Registered User
Location: CA
 
Join Date: May 2010
Posts: 27
Mein Auto: 2009 335d; 2014 i3
I think you answered my question, 80-90%. I was more interested in L1 and L2 comparison simply because you would need to pay extra to set up L2 station at home. Assuming charging time is not a big issue at home, I would choose the system that has better power conversion efficiency.

My commute is 35 miles round trip so overnight with L1 is sufficient to cover that range. Sounds like there is no advantage for me to get L2 for my house.

thanks!
Reply With Quote
  #13  
Old 09-22-2014, 08:28 AM
ultraturtle ultraturtle is offline
****
Location: Peachtree City, GA
 
Join Date: Sep 2013
Posts: 19
Mein Auto: 2002 325iT, 2007 325i
Quote:
Originally Posted by bayarea2007 View Post
anyone knows the power efficiency comparison between DC, L2, and L1 charging methods?
The most efficient DC to DC converters on the market can reach efficiencies in to the mid 90% range, but for a wall to battery comparison with AC EVSEs, you have to factor in the typical 85% efficiency of the AC to DC conversion, for 81% efficiency at best.

The EPA measures wall to battery efficiency for the i3 at 85%, but we do not definitively know whether they use an L1 or L2 EVSE in their testing. 85% is a widespread observation for L2 EVSEs, however.

Some folks have measured 81% efficiency from their L1 EVSEs.

From an efficiency perspective, L2 EVSEs are probably your best bet.
Reply With Quote
  #14  
Old 09-22-2014, 10:30 AM
Boatguy54 Boatguy54 is offline
Registered User
Location: San Francisco
 
Join Date: Aug 2014
Posts: 28
Mein Auto: i3 on order, Mercedes E
So I guess the question is how long would it take to recoup the cost of an L2 charger if the savings is 4%? At a nominal PG&E (Northern California) rate of $.20 / kWh, I calculate it would take more than 15yrs to recoup $1,000 for an L2 charger and installation.

If an L1 charger will do the job, no reason to spend on an L2 charger.
Reply With Quote
  #15  
Old 09-22-2014, 11:23 PM
bayarea2007 bayarea2007 is offline
Registered User
Location: CA
 
Join Date: May 2010
Posts: 27
Mein Auto: 2009 335d; 2014 i3
Agree, not worth it for me to install L2. Fortunately the only fast DC station offered by ChargePoint in NorCal is 5min away from me. I think I'm covered in case of emergency
Reply With Quote
  #16  
Old 09-24-2014, 09:59 PM
bimmer_fam's Avatar
bimmer_fam bimmer_fam is offline
Officially Welcomed to the 'Fest
Location: San Francisco
 
Join Date: Apr 2007
Posts: 2,023
Mein Auto: '13 328i, '13 Chevy Volt
Quote:
Originally Posted by Boatguy54 View Post
So I guess the question is how long would it take to recoup the cost of an L2 charger if the savings is 4%? At a nominal PG&E (Northern California) rate of $.20 / kWh, I calculate it would take more than 15yrs to recoup $1,000 for an L2 charger and installation.

If an L1 charger will do the job, no reason to spend on an L2 charger.
There is (or at least was) a CA state rebate that essentially covers cost of most (reasonable) L2 EVSEs as well as most installations.

But yeah, if you are able to recharge with L1 overnight, it covers probably 90%+ scenarios of EV ownership. Savings are obviously not in efficiency of L2 over L1, but in faster charge times and ability to schedule charging during grid "slower" hours with lower costs where applicable.
__________________
Chevy Volt (600+ MPG to date)
MY2013 328i (wife's new ride)
Retired:
ED2010 - MY11 328i SpaceGray/ChestnutBrwn, Premium, 6MT 05/06/10, re-delivered 07/24/2010
2010 Audi A4 Quattro
ED2007 - MY07 328i SparklingGraphite/Blk, ZSP, 6MT, 6FL 06/01/07, re-delivered 07/23/07
2007 X3si
2004 325i
Reply With Quote
Reply

Bookmarks

Tags
dc charging


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > BMW i3 / i8 / ActiveE
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



Forum Jump


All times are GMT -7. The time now is 11:49 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms