I've finished my 1,000 consecutive miles and here are the preliminary results: 1012.0 miles (91% EV) 231.33 kWh at 133.50 MPGe EV 1.88 gallons gasoline at 51 mpg HV 538 combined MPG 116 combined MPGe I've been assuming 12 kWh for a full overnight charge but I will now go back and plug in the actual OnStar numbers and will submit a final result by Monday.
I'm good to go. I checked the OnStar data. ChargePoint consistently reports 2.5% higher than OnStar for the same charging record. I averaged my overnight charge data from OnStar and adjusted it up by 2.5% to be consistent with the other ChargePoint records from daytime charging. The night charges average to 11.95 kWh (I assumed 12.0) so just go ahead with my existing numbers.
Uhm, yeah, so math and understanding all this is not my thing but there does seem to be large discrepancies between voltstats and myvolt etc. I pulled up energy consumption screen on myvolt for 12 months, since I've only owned it since march, and while it seems to not have all my miles updated for some reason, numbers are higher for MPGe. Is that because it can 'see' total electricity used and use that in the calculation while voltstats cannot? Can I just use this screen for more accurate numbers instead of voltstats, at least while it's still under 12 months?
BTW Volt owners (and Leaf and Tesla owners as well), you can now add these vehicles to your profile here on Priuschat if you so choose.
Voltstats incorrectly calculates all the EV miles at 93MPGe since they don't download the electric consumption. I have found some data problems at MyVolt as well. In November MyVolt erroneously added 32 gallons of fuel to my consumption.
Doh! Oh well, good thing I really don't care about numbers as much as I'm just happy with a car and it performing the way I'd like it to...
Since Top 10 efficiency list relies on the accuracy of the data, I will use the data you guys feel is the most accurate.
We can use MyVolt.com report if you feel it is more accurate. That is better than no data. The question I had was if the kWh includes charging loss or not. From my experience with PiP, vehicle cannot track charging loss since it is external to the car. We add 15% according to how EPA rated. For Volt, the loss is about 19% but I think that may be with 120v packed-in standard charger. If you only use L2 charger, we can use the loss % that Volt owners generally agree with.
I found that ChargePoint only reported about 2.5% higher than OnStar so it's clearly trying to account for charging overhead. I don't know if they adjust the numbers based on a table of average charging overhead at different voltages and amperages or if the car itself has extra hardware (like in a ChargePoint station) that measures the power conceptually at the J1772 socket before any of charging overhead happens.
I think what has been discovered is that there is a significant variance, driven mainly by ambient temperature and voltage. The Volt has an active temperature management system for the battery pack so charging during the heat of the day exposed to the summer sun can vary quite a bit from charging in the cool of the night. Including the energy consumed to heat and cool the battery and the cabin probably should be excluded from MPGe calculations. If someone charges their EV in a climate controlled garage, does the energy used by the garage go into the MPGe calculation?
Nah, it just doesn't matter much to me, that's all USB and I'd personally rather not have anything displayed knowing it has discrepancies, that's all. It's like fuelly which I tried for a while on both my 2010 and 2012 Prius and then gave up; I just don't care enough about numbers to track my own data for any vehicle whether it be mpg, mpge etc.
All these efficiency comments frankly confuse me... However, here are my VoltStats numbers: Last Updated:Last Updated:8/6/2013 10:45:38 AM CST EV Miles:16571.95 #220 / 86.3% Total Miles:19278.08 #305 / 81.0% EV %:86.0% #593 / 63.0% MPG:257.93 #528 / 67.1% MPGe:76.22 #490 / 69.5% MPGCS:36.21 #453 / 71.8% #453 / 71.8%
Is OnStar data the same as from MyVolt.com? If the difference is only 2.5%, we should use that data and deem as "good enough". How about the packed-in L1 charges? Does OnStar add the charging loss? I don't see how it can... I think EPA adds every kWh coming from the wall to the vehicle. Whether it was used to heat/cool the car or to charge the battery. The vehicle is consuming electricity afterall. Pre-heating the vehicle will result in higher efficiency later on but the energy spent needs to be counted. We should not include external factors such as the weather or the location we live or where we charge the car. EPA does not include it and we should follow EPA guideline for the purpose of valid comparison. Added you to the list. Do you have a report from MyVolt.com? It seems to be more accurate than VoltStats. This MPGe efficiency is basically a combination electricity and gasoline consumption. Per EPA, 33.7 kWh of electricity is equivalent to a gallon of gas. We add up the miles you have driven and divided by gallons (and the equivalent) consumed.
Here are the numbers from the last 12 months from MyVolt. The lifetime kWH/100mi has never worked for me on MyVolt. Thanks for collating this stuff, it's interesting. Energy Consumption Select Time Frame 12 months Electric Miles: 12,395 Gas Miles: 2,075 Total Miles: 14,470 Fuel Economy: 255 MPG Combined Economy: 80 MPGe Total Fuel Used: 57 gal Total Electricity Used: 4,223 kW-hr
My July report: Fuel Economy: 136 mpg Electric Consumption: 32 kW-hr/100 miles Electric Miles: 777 Gas Miles: 267 Total Miles: 1,044 Percentage on Electric: 74 % Estimated Gallons of Fuel Saved: Click here for important calculation details. 38 gal Estimated CO2 Avoided: Click here for important calculation details. 732 lbs
