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Re: Level 3 (public quick charge stations)

Posted: Thu Mar 03, 2011 1:40 am
by lonndoggie
drees wrote:
planet4ever wrote:
Vincent wrote:There's no need for an inverter as our systems produce pure AC from the get-go.
But ... but ... L3 is DC, not AC.
Yep. A truly integrated mobile quick charge station would integrate that huge L3 DC quick charge station into the area under the flatbed and get rid of the AC/DC conversion which saps an extra 5-10% efficiency out of the system.
Yeah, but, they don't need an inverter because they start with AC (must be an alternator, not a generator)...so they need a rectifier instead!

Re: Level 3 (public quick charge stations)

Posted: Thu Mar 03, 2011 8:08 am
by TomT
I don't think that would buy you anything since the charger still needs to control the charging current and that is actually easier to do on the AC side of the equation.

>>> A truly integrated mobile quick charge station would integrate that huge L3 DC quick charge station into the area under the flatbed and get rid of the AC/DC conversion which saps an extra 5-10% efficiency out of the system.

Re: Level 3 (public quick charge stations)

Posted: Thu Mar 03, 2011 8:54 am
by evnow
Vincent wrote:i-MiEV has a 16kW battery pack typical charge is around 12.8kWh (80% charge)

Assume the duramax is 40% efficient, our generator is 90% efficient and the charger is 95% efficient.

38.2 kWh * .4 = 15.28 kWh * .9 = 13.75kWh * .95 = 13.1 kWh or approximately 12.8 kWh
Interesting. So, you think charging is 95% efficient ? This would include ac-dc conversion at the charger + battery charging losses ...

Re: Level 3 (public quick charge stations)

Posted: Thu Mar 03, 2011 9:19 am
by DaveinOlyWA
mine isnt. it would appear to be the low to mid 80's for me at 120 volts. quick charges tend to generate more heat.

Re: Level 3 (public quick charge stations)

Posted: Thu Mar 03, 2011 9:21 am
by evnow
DaveinOlyWA wrote:mine isnt. it would appear to be the low to mid 80's for me at 120 volts
How can you tell ?

Re: Level 3 (public quick charge stations)

Posted: Thu Mar 03, 2011 9:28 am
by DaveinOlyWA
evnow wrote:
DaveinOlyWA wrote:mine isnt. it would appear to be the low to mid 80's for me at 120 volts
How can you tell ?

that is a good question and that is why i dont have a specific #. but what i do have is an exact figure for what i have taken out of the wall.

and i have what the car says i have averaged as far as miles per KWH. the lifetime figure from the car is 4.1 and its not resettable. at least i have not figured out that.

then i take carwings data (with a grain of salt) and provide guess work. my efficiency could easily be as low as 75%

Re: Level 3 (public quick charge stations)

Posted: Thu Mar 03, 2011 9:54 am
by Vincent
lonndoggie wrote:
drees wrote:
Vincent wrote:There's no need for an inverter as our systems produce pure AC from the get-go.
But ... but ... L3 is DC, not AC.
Yep. A truly integrated mobile quick charge station would integrate that huge L3 DC quick charge station into the area under the flatbed and get rid of the AC/DC conversion which saps an extra 5-10% efficiency out of the system.
Yeah, but, they don't need an inverter because they start with AC (must be an alternator, not a generator)...so they need a rectifier instead![/quote]

The generator used for this application generates 60kW of 3-phase AC power at 60hz. We do not require an inverter on our system as the L3 charger has an inverter integrated into it. The L3 is a commercial grade system designed for permanent mounting to be tied to the grid (AC) at a gas station or shopping mall.

Regarding the comment about "truly integrated mobile quick charge station", the truck you saw in the pictures and video is a "proof of concept" vehicle which was assembled just to prove that we could do it. We used an existing, off the shelf L3 charger and mounted it to a truck equipped with our generator system. It was never designed or built to be sold with the equipment configured in such a way.

Now that we know that the system works, we are designing a production unit of an EV Rescue/Recovery truck which will be commercially available. The design of the production unit includes reconfiguration of the L3 unit for mobile application so that it fits in a much smaller space (think of a highway box or a service body truck). We're hoping to have a true production unit ready by June.

Thanks for the great feedback. Keep it coming!

Vincent

Re: Level 3 (public quick charge stations)

Posted: Thu Mar 03, 2011 10:31 am
by wsbca
DaveinOlyWA wrote: the lifetime figure from the car is 4.1 and its not resettable. at least i have not figured out that.
The average energy economy on the dash can be reset, if you want to do so, by holding down the upper right button of the square array of 4 buttons to the left of the steering column (similar to reseting the trip odometers by holding down the lower left button) - see page 2-27 of the main manual.

On the center console "energy" screens, you can save and reset that version of energy economy - the current average adds a new column to the history histogram and it starts over. To do that, use the "reset" button on the Energy Economy screen (Nav manual pages 2-7,2-8). Then when you drill down to History, you'll see an additional column.

I agree that if the car's own average economy figure has any validity at all (the 4.1 figure in your example above, which is pretty much what we are getting), the recharge efficiency (all aspects from wall to when the car starts measuring it) is on the order of 75-80%.

Re: Level 3 (public quick charge stations)

Posted: Thu Mar 03, 2011 11:17 am
by DaveinOlyWA
wsbca wrote:
DaveinOlyWA wrote: the lifetime figure from the car is 4.1 and its not resettable. at least i have not figured out that.
The average energy economy on the dash can be reset, if you want to do so, by holding down the upper right button of the square array of 4 buttons to the left of the steering column (similar to reseting the trip odometers by holding down the lower left button) - see page 2-27 of the main manual.

On the center console "energy" screens, you can save and reset that version of energy economy - the current average adds a new column to the history histogram and it starts over. To do that, use the "reset" button on the Energy Economy screen (Nav manual pages 2-7,2-8). Then when you drill down to History, you'll see an additional column.

I agree that if the car's own average economy figure has any validity at all (the 4.1 figure in your example above, which is pretty much what we are getting), the recharge overhead (all aspects from wall to when the car starts measuring it) is on the order of 75-80%.

thanks for info on LT reset... i never read manual. maybe i should.

as far as the trip meter on energy screen, i reset set that daily and use it for a guideline of energy efficiency as well and that is giving me around 70-75% but that is penalized on climate controls which has to be factored out of the equation thus the carwings data on accessories reference

Re: Level 3 (public quick charge stations)

Posted: Fri Mar 04, 2011 9:39 am
by mwalsh
L3 charger at West Way Nissan, Oxford, UK:

Image