# Losing charge



## rovun (6 mo ago)

I’ve noticed in the past week I am losing significantly more “miles” on my battery than I’m actually driving. For example, I drove 45 miles to a conference but upon arriving, the miles to “empty” on my battery read that I had lost 77 miles. It was cold that day but I understand cold can take an extra 30% not 50%. Also my daily commute is 16 miles one way but upon arriving at work today I had “burned” 31 miles.

Any thoughts?


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## DocScott (Mar 6, 2019)

Several questions: How cold? Are the routes hilly? Are you leaving with a full charge? Is this a change from what used to happen on the same routes?

There are several combinations that can produce the kind of results you're seeing. For example, if the route is hilly, then in cold weather regen can be limited. Thus, when you go down a hill you don't recover as much energy as when it's warmer. Combine that with the general lower efficiencies in cold weather, and it can indeed amount to 50% decreases in efficiency.


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## Bigriver (Jan 26, 2018)

rovun said:


> I drove 45 miles to a conference but upon arriving, the miles to “empty” on my battery read that I had lost 77 miles.


Welcome to the forum. This is definitely a FAQ among newer Tesla owners.

The first clarification I would make is that the number of miles listed next to the battery icon is not the distance to empty. It is the “rated miles” the car could go under certain EPA conditions. It is better thought of as the equivalent of the gas gauge and thus many of us recommend that you change it to % (Display option). Distance to empty is provided at the far right in the energy graph (consumption tab), andcan both increase and decrease, reflecting your current driving conditions, with you being able to select seeing it based on last 5, 15 or 30 miles.









It is common that it takes more rated miles from the battery to equal an actual mile driven. Outside temperature and speed are usually the biggest factors, but there are many reasons, as @DocScott mentioned above.

My next question to you would be whether the rated miles used that you quoted were noted immediately after the drive, or whether that includes any energy used while the car was not being driven. Unlike a gas car, a Tesla does use some energy when it is just sitting, particularly if Sentry mode is on.


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## Jim H (Feb 11, 2017)

rovun said:


> I’ve noticed in the past week I am losing significantly more “miles” on my battery than I’m actually driving. For example, I drove 45 miles to a conference but upon arriving, the miles to “empty” on my battery read that I had lost 77 miles. It was cold that day but I understand cold can take an extra 30% not 50%. Also my daily commute is 16 miles one way but upon arriving at work today I had “burned” 31 miles.
> 
> Any thoughts?


How long have you owned your car? Seen any similar drain before? You indicate it was cold. Heater on cold? Seat warmers on cold?
Cold weather we all know is bad for range. Hills, rough roads, weather, same. 
Your post says drove 45 miles, but 77 miles was indicated loss. Need to look at your energy usage to have an idea on what's going on, but given the right conditions, yes your sited battery drain is possible. 
When I do a common trip that is 600 miles, the going part has a lot of downhills. When I return I spend $5 more on charging going back up those same hills.


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## Ed Woodrick (May 26, 2018)

What speeds are you driving. If you are in a cold are and driving 75 mph, 50% loss is easy.


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## SyncTwogether (12 mo ago)

I don't know if this might help, but wanted to say that range on mine sometimes changes based on the weather, things I do the following to get more range : 

-throttle percentage
-accelerate during downward slopes
-considered swapping the performance wheels but these are the most beautiful wheels I've ever seen
-less ac use
-take more efficient routes (less stops along the way)
-avoid McDonalds hehe


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## Ed Woodrick (May 26, 2018)

rovun said:


> I’ve noticed in the past week I am losing significantly more “miles” on my battery than I’m actually driving. For example, I drove 45 miles to a conference but upon arriving, the miles to “empty” on my battery read that I had lost 77 miles. It was cold that day but I understand cold can take an extra 30% not 50%. Also my daily commute is 16 miles one way but upon arriving at work today I had “burned” 31 miles.
> 
> Any thoughts?


And as I reread your question, don't assume that miles driven equal the range on the main page of the car. About the only thing that you can assume about the miles remaining gauge is that it is wrong. Look at the energy graphs for what reality is. While it doesn't seem like your situation lots of short trips will take more power than the same length long trip, 

When you look at the energy graphs, you can see what your actual utilization is and see what increases the utilization and what decreases it. Don't take my numbers as gospel, I'm tryinf to remember the actual numbers, but if you are doing as good as 250W/mi, then you are doing pretty good. If you are up to 400W/mi, then there are room for improvement. Most other vehicles tend to list this as miles per kWh, the reciprocal so 250W/mi (1000/250) is 4 mi/kWh. And if you are looking at a 72 kWh battery back then 250W/mi would be 284 miles range.

Now, with the said, the energy graph can go negative. What would that mean. I've had mine fully negative (green) for 15 minutes worth of driving, what was I doing?


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## DocScott (Mar 6, 2019)

Ed Woodrick said:


> When you look at the energy graphs, you can see what your actual utilization is and see what increases the utilization and what decreases it. Don't take my numbers as gospel, I'm tryinf to remember the actual numbers, but if you are doing as good as 250W/mi, then you are doing pretty good. If you are up to 400W/mi, then there are room for improvement. Most other vehicles tend to list this as miles per kWh, the reciprocal so 250W/mi (1000/250) is 4 mi/kWh. And if you are looking at a 72 kWh battery back then 250W/mi would be 284 miles range.


I agree with this idea, but the specific values depend pretty strongly on which trim you have.

For those of us who managed to snag a LR RWD before they were discontinued, 220 Wh/mi is pretty good; I'd say at 270 Wh/mi there's room for improvement. Of course, in winter those get bumped up quite a bit.

If you have AWD those numbers will be a bit higher (meaning the efficiency is lower).


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## DocScott (Mar 6, 2019)

Ed Woodrick said:


> Now, with the said, the energy graph can go negative. What would that mean. I've had mine fully negative (green) for 15 minutes worth of driving, what was I doing?


You were going downhill, and recharging the battery through regen while driving.

If it's just a minute or so, it can mean you're slowing down. But long periods of time always, in my experience, mean driving downhill.


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## Ed Woodrick (May 26, 2018)

DocScott said:


> You were going downhill, and recharging the battery through regen while driving.
> 
> If it's just a minute or so, it can mean you're slowing down. But long periods of time always, in my experience, mean driving downhill.


Yeah, but it's the original poster that I was talking to.


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