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Discussion Starter #1
Hello everybody

I have had a Model 3 Performance for two months. I’m new to EVs, and just getting used to everything.

My most frequent journey is about 110 miles round trip. I start at about 07:00 with 80% battery and get back 17:00–19:00.

Even if I drive the car on Chill acceleration mode like a sainted aunt, I’m lucky to get home with 20% charge left, and it has got worse in the last couple of days with sub-zero temperatures in the morning. The new scheduled departure charging mode is nice for a toasty, defrosted car in the morning, but doesn’t seem to help much on range.

is this what I should expect, the car seems nowhere near capable of doing about 300 miles as advertised.
 

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So you're using about 45kwh (60% of the battery) in a 110 mile round trip, which would be about 380Wh/mi which is somewhat high for a model 3 (the ranges are calculated on 250 in summer, winter will be somewhat higher but you're at the high end of even that).

OTOH we don't know your journey.. lots of hills will kill it - regen down a hill never gets back as much as it costs gettting up the hill. Driving >70mph (wind resistance increase with the square of speed), that kind of thing.

Scheduled departure should help as you're heating the car on charge which means it's not affecting range trying to warm the car from cold.
 

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I guess doesn't really matter if your longest journey is within range?

You may find table at link below useful - with 20" sticky tyres the only way to get 300 real miles is to charge fully and drive at 65 in warm, dry weather.

 

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380Wh/m is about what I'm returning on a short daily journey to work which is pretty hilly with a bit of stop/start traffic (on a stone cold battery).
 

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Discussion Starter #6
Wow, thank you all for such prompt and helpful replies!

The energy graph shows an average for the last 30 miles of 366Wh/mi, but today was not my normal trip – much flatter. My usual daily trip is pretty hilly. I was always puzzled by the ‘typical’ dashed line on the consumption graph. I can’t see any of my real-world usage getting down to that level.

I already worked out that driving it like it was stolen had an adverse effect on range, but I expected that. :ROFLMAO:

Forgive my ignorance, but why does the battery need to be warm? Is it just that the chemistry is more efficient at a particular temperature? Does the scheduled departure feature warm it up?

Also, why 6AM? My cheap power goes until 07:00.

@proddick, thanks for that link. I shall peruse later. The issue for me is returning home and not really be able to use the car in the evening. I understood that one was supposed to strive to keep the battery between 80% and 20%. Is that wrong?

Is there anything else that I might be unwittingly doing that might affect range? For example, I cant plug it in at work, so is there stuff I should switch off?
 

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Why 6AM?

Tesla decided in all their wisdom to hardcode the time to 6AM which is where the tariff change happens in their area.
 

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understood that one was supposed to strive to keep the battery between 80% and 20%. Is that wrong?
There is a lot of paranoia about batteries here with no real world, car battery data to substantiate it. A few will point to random tests of cells in a lab, but at this point little is really known what is best. Hopefully over time Tesla will release data - they certainly will have it. Also every car will be different - for example, problems with a Leaf (no proper thermal management) are not relevant to a Tesla.

If you need range to go out in the evening, just charge to (even) 100% overnight. Providing you do not leave it at that state for long (or do it too often) is fine IMO. Also, you can always plug in when you get home and top up a bit (which I do occasionally) but obviously costs more if you have cheap overnight rate.

The 6am is hard coded to the Tesla scheduled departure feature at present. Hopefully be changeable in future.

Unless your work car park is dodgy, you could switch off Sentry as that does use quite a bit of power.
 

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I'm in a similar situation for my commuting distance but recently I have started to stop off on the way home at a rapid for 30 minutes or so. What I find is that cabin heating eats into it quite a bit too. What have you got the heating set at?
 

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Discussion Starter #11
... recently I have started to stop off on the way home at a rapid for 30 minutes or so …
I wish that were an option for me.

20.5°C

In general, I find the cabin heating rubbish compared to the BMW. It seems to be difficult to keep a constant temperature.
 

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Hang on a sec, Tesla’s scheduled departure feature has a hardcoded time of 6am, that you can’t change??
 

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My usage as follows:-

Departure set to 08:00am with SoC of 80%
I actually leave at around 08:30am to do the school run, about 1.6 miles.
Then from there I do around 48 miles to work, arrive at the office around 1000am with around 55-60% SoC.
Leave work around 1800pm with about 50-55% SoC and get home around 1900pm with 25-30% SoC.
If I stick to chilled out driving I am around 300m/KWh.
Lowest I’ve got it to is 264m/KWh over 47 miles driving 52 mins.
 

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I have a M3P in which I commute 30 miles each way for work. This morning, when the temp was -1C, I got 348 Wh/m in Sport mode driving at speeds of between 20 mph and 60 mph, with one overtake on a country road, and averaging ~30 mph. I charge at home to 80% between 12.30 am and 4.30 am when my electrons only cost 5p per KWh, and then preheat the car for 20 min prior to departure around 6.40 am, which seems to prevent restricted regen. Yesterday evening my journey home used ~333 Wh/m, without any preheating, and restricted regen initially, which was better than this morning probably because of the higher ambient temperatures.

I have my cabin temp set for 20C, with air con off, and one bar of seat heating. Using the seat heaters is supposed to be more efficient than heating using the ventilation system. I have tried turning off the ventilation system and just using the seat heater, but this leads to the windows misting up and cold hands and feet!

There has been quite a bit of analysis of how quickly batteries degrade depending on the charging regime, which I have come across on the web. Basically lots of supercharging, like everyday, is bad, i.e. speeds up the decline in battery capacity. Routinely charging to 100% increases the deterioration in battery capacity but is not as bad as routinely supercharging. Charging slowly between 30% to 70% is very good for reducing battery deg, but the differences between this and say 50% to 90% are very small. From memory such charging regimes would lead to 15% to 20% loss of range over around 5000 charge cycles (e.g. charging 250 times per year over 20 years) - I will try to find the article and graphs that show this later today and post a link.
 

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So in essence 100 miles of driving in cold weather uses 50% of the battery?
For me works out about 44% approx for 100 miles of driving. Mostly all at motorway speeds set to 70mph, aircon on all the way at 20.5.
 

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On a typical cold day in my SR+ it would not be unreasonable to see 320 wh/mi and with a lot of that up to 70 mph. So yeah an M3P can be up to 20% less efficient on a similar journey.

Batteries have internal resistance which reduces with increasing temperature so Tesla target mid 20s C for driving and up to 50 C for the fastest supercharging speed. You also have ~50% more battery mass to heat up so that can also add to the initial extra consumption in cold weather.
 

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So in essence 100 miles of driving in cold weather uses 50% of the battery?
That's about right. A couple of weeks ago when the ambient temperatures were higher (~12 C) I did a round trip of around 210 to 220 miles with an overnight stop mostly on motorway at an average speed of 40 to 45 mph due to roadworks/traffic. The car (M3P) indicated on my way home that if I didn't stop for a charge I would get home with minus 6% range. This was when driving in Chill mode and losing around 5% SOC overnight due to Sentry Mode. I must admit I was somewhat disappointed in the low range, but assume it was due to the drizzle that was falling for most of the journey.
 
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