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Just spoke to the Tesla tech, the heater is connected to the utility input via a relay. That's why they're a bit feeble on 110v.
So, mystery solved, the heaters don't come on during driving.
So, mystery solved, the heaters don't come on during driving.
If the battery is cold it will exhibit higher internal resistance. That will cause both increased internal heating and lower power output. The lost efficiency is self-limiting though, as it will warm up the pack.
Cold battery would explain miles to empty falling away faster but doesn't explain why we see higher power usage.
Still some mystery left to be solved.
Still some mystery left to be solved.
Okay, today I was finally able to obtain ideal range on a longer highway drive. Here are the numbers:
Miles ideal range used: 42
Miles driven: 47.0 (12% above ideal)
Energy: 219 Wh/mi
Outside temperature: 10C
Speed: between 45 and 50mph
I set out to try and use less than 225 Wh/mi and ended up doing a bit better than that. I was really poking along though most of the way. I had to stop 3x for toll gates, and a number of other times I came almost to halt because of traffic. Other than that is was just controlled, conservative driving.
That was about as slow as I could go without really getting in peoples' way. I think other drivers thought it a bit odd that such a fast looking car was just creeping along! The 12% above ideal range I suppose means that at the pace I travelled, I would have gone around 275 miles before completely draining the battery. Driving at 250 Wh/mi or less at whatever speed you need to stay under seems to be the way to obtain ideal range.
Miles ideal range used: 42
Miles driven: 47.0 (12% above ideal)
Energy: 219 Wh/mi
Outside temperature: 10C
Speed: between 45 and 50mph
I set out to try and use less than 225 Wh/mi and ended up doing a bit better than that. I was really poking along though most of the way. I had to stop 3x for toll gates, and a number of other times I came almost to halt because of traffic. Other than that is was just controlled, conservative driving.
That was about as slow as I could go without really getting in peoples' way. I think other drivers thought it a bit odd that such a fast looking car was just creeping along! The 12% above ideal range I suppose means that at the pace I travelled, I would have gone around 275 miles before completely draining the battery. Driving at 250 Wh/mi or less at whatever speed you need to stay under seems to be the way to obtain ideal range.
On Sundays I do a 50 mile run at around 35mph, I usually see the benefit the next morning; ideal miles 190, estimated 210.
Okay, finally today I was able to do city stop and go driving and break through ideal range. The difference? Today was warm, about 16C rather than 2C or so as on my previous in-town drives (also it was daytime, so no lights but I don't think that was too much of a factor).
Anyway, in stop and go traffic on a flat 10 mile course, I was able to drive 10 miles using up just 8 ideal miles, and energy used was just 200 Wh/mi. I started very slowly from stop lights and used no friction braking other than perhaps once or twice on the whole drive. I was generally driving about 30 miles per hour, but there were so many lights I could not get up to speed often. Basically it's always like that right in the middle of the city...
So anyway, as some people have mentioned on this thread, it really seems like a warm battery is crucial in obtaining ideal range -- possibly the battery warms up with use even on a cold day, but it does not seem to do so in the first 10 miles or so on my tests... since the weather is gettng warmer now, I might not have a chance to do a long drive in cold weather for about 10 more months!
Anyway, in stop and go traffic on a flat 10 mile course, I was able to drive 10 miles using up just 8 ideal miles, and energy used was just 200 Wh/mi. I started very slowly from stop lights and used no friction braking other than perhaps once or twice on the whole drive. I was generally driving about 30 miles per hour, but there were so many lights I could not get up to speed often. Basically it's always like that right in the middle of the city...
So anyway, as some people have mentioned on this thread, it really seems like a warm battery is crucial in obtaining ideal range -- possibly the battery warms up with use even on a cold day, but it does not seem to do so in the first 10 miles or so on my tests... since the weather is gettng warmer now, I might not have a chance to do a long drive in cold weather for about 10 more months!
Indeed
There was a "Tuned" Honda Civic at the traffic light last friday, it had a sticker below it's numberplate:
"If you can read this.... Wait till the VTEC kicks in!"
Well, I've been waiting for that VTEC to kick in, but I was still able to read it!
At the next traffic light we had to stop, but it went green when he arrived, so even while having a rolling start, he lost... Hehe
Yeah - it's almost like shooting fish in a barrel. The motorbikes get a bit annoyed when you do it to them :smile:
Apparently I also have the same traffic light problem. My estimated range isn't that bad, closer to 200, but my rear tires are nearly worn out after 6700 km.
Was it raining? I saw this morning that I was in the high 300's where I'd normally be in the mid 200's. It was sleeting and I think I could sense extra drag.
...and the F430's and the 911 Turbo's IME but not the very very sorted Nissan something that got a rolling head start on me that I couldn't catch; sorry to let the side down. One consolation was that the entire road reaked of half-burnt fuel and clutch insides whilst the Tesla just shrugged it off as daily life.
Battery Cooling
dpeilow,
Battery cooling turns on. Even if it is cold outside the battery will heat up on a long drive. Charging and driving in Range mode gives you the best chance of keeping cooling off but even then it will likely turn on toward the end of a long distance, full battery consumption, drive.
And regen is great but it charges the battery at high amperage and will heat the battery faster than not using regen.
Zak
dpeilow,
Battery cooling turns on. Even if it is cold outside the battery will heat up on a long drive. Charging and driving in Range mode gives you the best chance of keeping cooling off but even then it will likely turn on toward the end of a long distance, full battery consumption, drive.
And regen is great but it charges the battery at high amperage and will heat the battery faster than not using regen.
Zak
I thought Performance mode would keep any battery cooling off as it allows the battery temp to climb higher no? Or, are you saying that the reduced consumption keeps the batteries cool?
...thanks for the input!
...thanks for the input!
It is a complicated equation that would require long discussion, debate, and modeling to come up with the correct answer given a specific situation. But there are a number of general principles that will help you improve your consumption if desired.
Performance mode does allow the battery temperature to climb higher (at least it used to but this may no longer be true with recent firmware updates. All modes may now reach the same temperature, or at least close to it). The difference between Performance and Range is that Range mode cools the battery further during charge time. At the end of a full Range charge cycle you will have a cooler battery than if you begin in Performance mode. This allows more miles to be driven before cooling kicks in.
While driving the power profiles are also different. Range mode will prevent you from pulling as much juice from the battery than you would in Standard or Performance mode. Slower energy release equals a cooler battery. You could probably equal Range energy usage in the other modes but it is difficult to not take advantage of the power at least a couple times on a long drive. The power is there after all so you want to use it.
Zak
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