ajdelange
Well-known member
- First Name
- A. J.
- Joined
- Dec 8, 2019
- Messages
- 2,173
- Reaction score
- 2,283
- Location
- Virginia/Quebec
- Vehicles
- Tesla X LR+, Lexus SUV, Toyota SR5, Toyota Landcruiser
- Occupation
- EE (Retired)
Let's begin by assuming that the trip is equivalent to EPA driving. The Dual has an EPA range of 300 miles (IIRC, if I don't just put in the right number). In such a case you would use 20/300 = 6.7% of the battery were you a better than average driver. Accumulated data on the other models indicate that most people achieve about 85% of EPA range so you might expect to use 20/(0.85*300) = 7.8% of the battery. But you are hardly under EPA conditions going up a mountain off road. Your actual consumption can vary all over the place. Being really pessimistic it could treble. In such a case your battery use would be 3*7.8 = 23.4% of the battery. Under less demanding conditions it might only double to 15.6%. And if the "trail" is a hard packed dirt road the increased demand could be a factor less than 2. In planning such a trip initially I would plan for as much as a quarter of the capacity being used and when I got to the trail head would set one of the trip odometers and record the actual consumption for a more accurate plan on subsequent visits.
It really is that simple and I expect you might be a little disappointed. So let's now burrow in a bit deeper. Let's assume the CT weighs 3000 kg. The elevation change is 2660' and there are (12*2.54/100) meters in a foot. The acceleration due to gravity is 1g = 9.8 m/sec/sec and there are 3600 seconds in an hour. To haul that mass up that high requires
3000*2660*(12*2.54/100)*9.8/3600 = 6621.27 Watt hours of energy which must come from the battery. Again, IIRC, the Dual CT is expected to have a 100 kWh battery and again, if you have another number in mind use that. Thus just the change in elevation will use 6.6% of the battery. But, in theory, you get that back when you go down the mountain. But you don't get it all back. Perhaps 75 % of it so of the 6.6 kWh (6.6%) you would only actually lose 6.6/4 = 1.65% to the elevation change. Unfortunately, the gravitational component of the energy requirement is the only one for which we can make good estimates. Most of the extra loss comes from the wheels. Experience is really your best guide with respect to those losses. You will gain that if you are observant. A tool like TeslaFi will do all your logging for you if you are willing to pay the fee (modest) and are not one of the nutters who is upset that some Swedish guy has a record of where you have driven and plans to sell it to the CIA.
Now I have a question. What is it with propane? I certainly wouldn't consider hauling propane bottles up a mountain in the bed of my truck and PLEASE don't ever even think about putting one of those in the cab. My sister had (note past tense) a friend that did that. I had a 30 lb CO2 siphon bottle valve fail on me in the bed of my pickup a block from Roberts. Were I to buy a portable generator for this purpose I might well buy a dual fuel (so I could hook it to my bulk tank at home) but would use a Jerry can and gasoline for any trips.
It really is that simple and I expect you might be a little disappointed. So let's now burrow in a bit deeper. Let's assume the CT weighs 3000 kg. The elevation change is 2660' and there are (12*2.54/100) meters in a foot. The acceleration due to gravity is 1g = 9.8 m/sec/sec and there are 3600 seconds in an hour. To haul that mass up that high requires
3000*2660*(12*2.54/100)*9.8/3600 = 6621.27 Watt hours of energy which must come from the battery. Again, IIRC, the Dual CT is expected to have a 100 kWh battery and again, if you have another number in mind use that. Thus just the change in elevation will use 6.6% of the battery. But, in theory, you get that back when you go down the mountain. But you don't get it all back. Perhaps 75 % of it so of the 6.6 kWh (6.6%) you would only actually lose 6.6/4 = 1.65% to the elevation change. Unfortunately, the gravitational component of the energy requirement is the only one for which we can make good estimates. Most of the extra loss comes from the wheels. Experience is really your best guide with respect to those losses. You will gain that if you are observant. A tool like TeslaFi will do all your logging for you if you are willing to pay the fee (modest) and are not one of the nutters who is upset that some Swedish guy has a record of where you have driven and plans to sell it to the CIA.
Now I have a question. What is it with propane? I certainly wouldn't consider hauling propane bottles up a mountain in the bed of my truck and PLEASE don't ever even think about putting one of those in the cab. My sister had (note past tense) a friend that did that. I had a 30 lb CO2 siphon bottle valve fail on me in the bed of my pickup a block from Roberts. Were I to buy a portable generator for this purpose I might well buy a dual fuel (so I could hook it to my bulk tank at home) but would use a Jerry can and gasoline for any trips.
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(This is based off of one of my local trails called Stony Pass in Silverton, CO) From these details, I will be able to put into perspective the CT's off-roading capabilities in some realistic environments. From here, we can maybe calculate what a full day of off-roading would look like and see at what point would we might consider carrying a generator and some propane tanks in a real-life situation