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Rated vs Ideal vs Projected and how to use them
- Thread starter Al Sherman
- Start date
Floating color coded range arcs right on the map would be very cool. Don't know how feasible it is though.
strider
Active Member
Think of Ideal as your "battery meter". Each "mile" is .33% of your battery or conversely, every 3 miles is 1% of your battery. This is the only way to know how much battery your truly have left. As others have said, projected is based on how you've been driving so if your trip is all downhill in one direction and uphill in the other then projected is hard to understand. For an example, read about how the Leaf battery gauge works.
On the Roadster I have it display Ideal on the touchscreen and Projected on the instrument panel and find that works well for me. I can glance down to the touchscreen to see my absolute battery remaining and look on the IP to see if I'm being a leadfoot. On the Model S I leave it in Ideal on the IC and if I'm taking a trip where I need to watch my consumption I have the Energy app up on the touchscreen and have it display the 5-mile average (lots of hills around me - if you live in flatter terrain you could use 15 or 30 miles)
On the Roadster I have it display Ideal on the touchscreen and Projected on the instrument panel and find that works well for me. I can glance down to the touchscreen to see my absolute battery remaining and look on the IP to see if I'm being a leadfoot. On the Model S I leave it in Ideal on the IC and if I'm taking a trip where I need to watch my consumption I have the Energy app up on the touchscreen and have it display the 5-mile average (lots of hills around me - if you live in flatter terrain you could use 15 or 30 miles)
I like that graphic to the left of the speedometer. I've left it at 'last 30 miles'. I have NO TECH so does that mean TM can't alter/remove anything remotely?? I.e. for me to get an upgrade I'll have to have TM email a file & I can then apply it using the USB port?? Not that I'm in any rush, just asking.
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strider
Active Member
But that is exactly what the Ideal readout is giving you, just with more granularity. If you set the dash display to read out Ideal, you can quickly see what 300 miles = 100%, 200 miles = 66%, 150 miles = 50%, etc. Rated works the same but I like round numbers :biggrin: It becomes second nature very soon to use the miles remaining instead of a %.
Hmm. There is no need for the algorithms to be so limited. tesla will start having driving data for vehicles, vehicle config, running settings (windows, climate),SOC, exact roads driven, their altitude profiles, driving patterns (accel & braking) weather conditions, etc.
if they are smart -and I think they are- they should be collecting all this data (in an anonymized/de-identified way, with final trip endpoints deleted yadda yadda). For everyone.
Then take good statistical approaches to weigh live car range estimates based on how your particular car/conditions/style/itinerary clusters.
As someone said- it can't know how you WILL be driving. But given how you are driving and are likely to be driving a lot can be done for you. Especially in those few situations when one cares. Early model S adopters I feel will need this less than latter adopters and Gen3.
X1188. Sorry if this is terse, sent from my phone.
if they are smart -and I think they are- they should be collecting all this data (in an anonymized/de-identified way, with final trip endpoints deleted yadda yadda). For everyone.
Then take good statistical approaches to weigh live car range estimates based on how your particular car/conditions/style/itinerary clusters.
As someone said- it can't know how you WILL be driving. But given how you are driving and are likely to be driving a lot can be done for you. Especially in those few situations when one cares. Early model S adopters I feel will need this less than latter adopters and Gen3.
X1188. Sorry if this is terse, sent from my phone.
Agreed. When some of us have said "we miss Projected", some have chimed in with "but it's not accurate" (or something like that). I believe they are missing the point. For many of us it's far more accurate than Rated or Ideal. If you're worried about even Projected "overestimating", then fine - add a customer knob in the settings that says "assume 25% worse than Projected used to show" where the 25 is adjustable. This isn't rocket science.
You're lucky that's an even number for you. But what about other battery packs? Or like me when you're in km?
If we really want a %, lets put a %.
Putting ideal miles is a fake sense of security and dangerous.
For example, right now my true range for a standard charge in the cold winter is more 135 miles.
Seemed as close a match for a thread as I could find for this questions.
After 1200 miles, I'm nowhere even close to the 300 wh/mile energy usage. I'm averaging 430 wh/mile. It's Oregon and a bit chilly, but nothing crazy cold. My driving is mostly 30-50mph city streets, about 35 miles a day, so I wouldn't expect that should be too far off the EPA "city mileage". I'm starting to wonder if the car has an issue or if real city usage isn't even close to the rated range.
After 1200 miles, I'm nowhere even close to the 300 wh/mile energy usage. I'm averaging 430 wh/mile. It's Oregon and a bit chilly, but nothing crazy cold. My driving is mostly 30-50mph city streets, about 35 miles a day, so I wouldn't expect that should be too far off the EPA "city mileage". I'm starting to wonder if the car has an issue or if real city usage isn't even close to the rated range.
Do you have climate control on? It's been COLD in Portland! Even if it's not 'crazy cold', having the heat on is having the heat on. My Leaf (Model S arrives in the spring) doesn't like the cold, and there is a huge difference in energy usage when the heat is on. Gloves, coat and scarf are always on in the Leaf.
Yep, I've got climate control on, but Tesla's webpage says such things have about a 10% impact. I'm seeing closer to 40% (430/300 ~= 143%).
Tesla's quote from their "Facts" page on accessory usage:
I just got my car and am getting between 450 Wh/mile and 400 Wh/mile on my normal driving trips. This is much more than I expected also. I have noticed that hills are much rougher on energy usage than I imagined, and I do not have the hang of gauging my regen properly yet.
I don't know how hilly your part of Oregon is but Atlanta is VERY hilly (and my part especially so). And I think heat power usage is understated by Tesla. Heat is going to take a good amount of power.
And apparently driving 85 sucks down 400+wH/mile even on flat stretches.
ChadS
Last tank of gas: March 2009
I just got back from a 3,000-mile trip where temps were below freezing every night, and usually only 40's or 50's during the day (although it did hit 70 one day). I've played with Tesla's calculator and compared it to my notes on energy usage, and here's my conclusions FOR LONG TRIPS:
The Model S HVAC, at full blast takes about 7.5kW. What % hit that is depends on how fast you are going. And of course you may not have it on full blast. AC takes less than heat (at 90 degrees Tesla says the range is the same as 70; Model S batteries must like it a little warmer than Roadster batteries). But at 60 – 70mph freeway speeds, it appears to take off 7% at 50 degrees (or 100 if you're driving in heat, although I didn't get to measure that), 13% for 32 or 120, 25% for 15. It appears about 1/3 of this hit happens even with HVAC off, so that’s the portion to manage the batteries vs 2/3 to keep the cabin comfortable.
So for a long highway trip at 32 degrees, expect a 13% hit for HVAC. That would change the nominal 60mph 308Wh/mi consumption to 348. Of course there are lots of other hits too, like faster speed, generous acceleration, heavier or sticker tires and wheels, wet roads, wind, hills, etc. I'm trying to tease the numbers all out and hope to post something soon.
Note that the "average" energy usage is much worse for short city trips for two reasons. One is that a constant draw is a larger percentage hit at slower speeds (see graph below to get a feel for the relative hit). Another is that a lot of the energy to get the car bits warm comes at the very beginning. It's the same reason why my old Honda Insight only got 46mpg in the winter until I put on a block heater, even though I averaged 60mpg overall and could get over 80 in the summer.
The Model S HVAC, at full blast takes about 7.5kW. What % hit that is depends on how fast you are going. And of course you may not have it on full blast. AC takes less than heat (at 90 degrees Tesla says the range is the same as 70; Model S batteries must like it a little warmer than Roadster batteries). But at 60 – 70mph freeway speeds, it appears to take off 7% at 50 degrees (or 100 if you're driving in heat, although I didn't get to measure that), 13% for 32 or 120, 25% for 15. It appears about 1/3 of this hit happens even with HVAC off, so that’s the portion to manage the batteries vs 2/3 to keep the cabin comfortable.
So for a long highway trip at 32 degrees, expect a 13% hit for HVAC. That would change the nominal 60mph 308Wh/mi consumption to 348. Of course there are lots of other hits too, like faster speed, generous acceleration, heavier or sticker tires and wheels, wet roads, wind, hills, etc. I'm trying to tease the numbers all out and hope to post something soon.
Note that the "average" energy usage is much worse for short city trips for two reasons. One is that a constant draw is a larger percentage hit at slower speeds (see graph below to get a feel for the relative hit). Another is that a lot of the energy to get the car bits warm comes at the very beginning. It's the same reason why my old Honda Insight only got 46mpg in the winter until I put on a block heater, even though I averaged 60mpg overall and could get over 80 in the summer.
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