Reduced Battery Life

[Kevin Ali]

Hi folks,

I am new to this forum but have had my Model S since September.

I am noticing, however, reduced battery range from actual kilometres driven to what the Tesla predicts I should have left.

Yesterday I began my trip with 314 km from the Supercharger and drove 98 km to my destination. On my arrival, my remaining kilometres was 168. This works out to be 48 km of less range than Tesla predicted I would have.

I am in Toronto and it is winter time, so for most of my trip I had heat on. That said, a 48 km discrepancy is not insignificant.

I have noticed reduced kilometres remaining than I should have on quite a few previous trips, but have not been formally tracking... which I will now begin to do.

I am wondering if this is par for the course? If so, it makes me a bit nervous as I would like to have confidence I will not run out of power on longer trips (or shorter round trips).

Would love to hear people's experiences if possible.

Thanks,

Kevin

 

[rxlawdude]

Let me guess: first time taking a road trip after cold temperatures have set in?

 

[Kevin Ali]

Let me guess: first time taking a road trip after cold temperatures have set in?

Not quite the first... I would say maybe had been out ten times before (one very long trip ... other short ones).

 

[Zextraterrestrial]

do you look at the 'trip' graph at all?
what speed do you drive? is there rain or snow? wind? what is the ambient temperature?

 

[Kevin Ali]

do you look at the 'trip' graph at all?
what speed do you drive? is there rain or snow? wind? what is the ambient temperature?

I was driving highway speeds for the most part, around 100 km/h. That said there were areas of slow moving traffic. Yes, there was snow, don't know wind speeds, and ambient temperature was maybe minus 10 degrees celsius.

I haven't looked at the trip graph. But would that actually help me get a better estimate before I commence a trip?

 

[animorph]

If you're looking at the battery charge for your range estimates, that's like looking at your gas gauge in an ICE car and multiplying by the official MPG to figure out miles remaining. It will depend on driving conditions, which are not accounted for in the battery charge reading.

If you use the navigation it will tell you the expected percent of battery remaining at your destination, and does include at least elevation changes and your driving habits to some extent. That's what you need to be looking at during long trips. If it looks tight, just slow down a bit and you should be fine.

If you want to know if a trip is feasible before entering the destination into the nav, try EVTripPlanner (web), ABetterRoutePlanner (web), or EVTO (phone app).

Canada may have a different "ideal" mileage readout, but I haven't heard any of the possibilities being very accurate.

 

[Gen3]

I just did a road trip from toronto to ottawa last week in a rented S 75. the cold temps make a huge difference. i agree with animorph, and would add that you can look at the energy usage page, and it will tell you expected range remaining based on last 10, 25 or 50 km, whatever you select. i found the navigation battery remaining at destination to be within a couple percent, as long as car is warm starting the trip and you keep speed within 10km/hr of speed limit. you can keep an eye on the percent at destination and adjust speed if it starts to drop.

 

[TexasEV]

Cold, snow, and your heat was on.

These posts come every winter from new owners. The battery meter rated range is the range on the EPA test cycle. If you’re not driving the EPA test cycle, all bets are off.

 

[tnt1971]

-10 Celcius is really going to decrease range. If you ran with no heat, you would still probably use 10% more battery than the rated range. With heat, depending on speed, it could be 30% or more at those temperatures.

I drove upstate NY one time when it was between 5 and 10 degrees Fahrenheit. I kept the heat off, used a blanket and just ran the seat heaters. Even with that I could not get it below 120% of rated range usage at 65MPH (a little more than 100 km/hr).

I will tell you that after driving about 120 miles at those temperatures, I got normal supercharging speeds when I stopped. I was even surprised to hear the cooling system come on as I was finishing charging. That shocked me at that ambient temperature.

 

[Rocky_H]

People who are used to driving gas cars are used to all of the heat being "free" because the engine wastes two thirds of the energy of the gasoline as heat and has to get rid of it every way it can (tailpipe, radiator, etc.). An electric car is so efficient it doesn't generate much waste heat, so heating the interior of the car is going to be using a resistive heating element which really sucks range. This is a new surprise to people. You are looking at 314km and thinking that is 314km for driving. Well, that would be, if it were just for driving. But that amount in the battery is all one pool of energy that provides everything, so it is X amount of driving + Y amount of heat. The heat is significant, so you're not going to get 314km of actual driving from that. In those really cold temperatures below freezing, you may see about 20-30% reduction in range, worst case.

It's not bad or wrong; it's just the way electric cars operate. You get the benefit of great efficiency most of the year, but in winter, you just need to be aware to budget more energy for heating.

 

[gavine]

People who are used to driving gas cars are used to all of the heat being "free" because the engine wastes two thirds of the energy of the gasoline as heat and has to get rid of it every way it can (tailpipe, radiator, etc.). An electric car is so efficient it doesn't generate much waste heat, so heating the interior of the car is going to be using a resistive heating element which really sucks range. This is a new surprise to people. You are looking at 314km and thinking that is 314km for driving. Well, that would be, if it were just for driving. But that amount in the battery is all one pool of energy that provides everything, so it is X amount of driving + Y amount of heat. The heat is significant, so you're not going to get 314km of actual driving from that. In those really cold temperatures below freezing, you may see about 20-30% reduction in range, worst case.

It's not bad or wrong; it's just the way electric cars operate. You get the benefit of great efficiency most of the year, but in winter, you just need to be aware to budget more energy for heating.

The seat heaters use much less energy than the cabin heater so, if you feel like you might be light on energy, use the seat heaters instead of the cabin heater. It makes a big difference on energy, but they still keep you mostly warm. Or, if you fell like you must use the cabin heater, don't go overboard with the temperature setting. Just set it high enough to take the chill-out but you don't need to make it super-hot like you might in a gas car where it's waste heat anyway.

 

[Kevin Ali]

Great feedback, learned a lot that is new to me here. My big concern was that I had a defective battery in some way. Happy to at least hear that my experience is what should be expected in the conditions that I am in. Thank you everybody.

 

[Gen3]

The seat heaters use much less energy than the cabin heater so, if you feel like you might be light on energy, use the seat heaters instead of the cabin heater. It makes a big difference on energy, but they still keep you mostly warm. Or, if you fell like you must use the cabin heater, don't go overboard with the temperature setting. Just set it high enough to take the chill-out but you don't need to make it super-hot like you might in a gas car where it's waste heat anyway.

Once you plug into a supercharger you can turn up the heat. I like to go full hot for a bit , especially with the footwell heat, before departure when it's really cold.

 

[Dax279]

Conditions must not have been too bad and your speed was pretty good as well to help with range. My add hoc estimate that I would have used for those conditions would have you seeing about 130 Kms left over and so the conditions were likely not as bad as you describe. In the worst conditions, I will estimate that I have only 55% of what the car is telling me and will watch the graph in the car as I drive.

The 55% is based off of other things I have read on here by other members that have spent a lot of effort measuring their car carefully over the winter.

 

[x4er0]

Hi folks,

I am new to this forum but have had my Model S since September.

I am noticing, however, reduced battery range from actual kilometres driven to what the Tesla predicts I should have left.

Yesterday I began my trip with 314 km from the Supercharger and drove 98 km to my destination. On my arrival, my remaining kilometres was 168. This works out to be 48 km of less range than Tesla predicted I would have.

I am in Toronto and it is winter time, so for most of my trip I had heat on. That said, a 48 km discrepancy is not insignificant.

I have noticed reduced kilometres remaining than I should have on quite a few previous trips, but have not been formally tracking... which I will now begin to do.

I am wondering if this is par for the course? If so, it makes me a bit nervous as I would like to have confidence I will not run out of power on longer trips (or shorter round trips).

Would love to hear people's experiences if possible.

Thanks,

Kevin

Like you i got my Tesla 100d in december (netherlands so cold), what i noticed is when i use a super charger my 100% is 509KM but when i use my homeplug 3 phase 16A i get 521 at 100%, so the car likes slow charging instead of being forced, try that.

I'm going to try the 13A socket charger, maybe i get 600KM at 100% and after that i charge with 5A single phase and get 670KM at 100% hehehehehe

 

[gavine]

Like you i got my Tesla 100d in december (netherlands so cold), what i noticed is when i use a super charger my 100% is 509KM but when i use my homeplug 3 phase 16A i get 521 at 100%, so the car likes slow charging instead of being forced, try that.

I'm going to try the 13A socket charger, maybe i get 600KM at 100% and after that i charge with 5A single phase and get 670KM at 100% hehehehehe

How often do you charge to 100%? It's not advisable to charge to 100% often. If you do, best practice it so drive shortly after. Lithium Ion batteries don't like sitting at 100% charge for extended periods of time. It causes degradation.

 

[x4er0]

How often do you charge to 100%? It's not advisable to charge to 100% often. If you do, best practice it so drive shortly after. Lithium Ion batteries don't like sitting at 100% charge for extended periods of time. It causes degradation.

I know, they get bloated, not for real as if we can see it with our eyes but don't you think the programmers made a "fool"proof design so that the batteries will never go to 100% for real. And yes after 100% i use the car within 15 minutes so they can discharge.

But like i said; they liked to get charged slow instead of forced/ raped/ give it a name

 

[Rocky_H]

but don't you think the programmers made a "fool"proof design so that the batteries will never go to 100% for real.

They did--it's called recommending to people to not do that often.

 

[David29]

My impression is that most Tesla veterans change the battery gauge to read in percentage, not km or miles, and that is what I do, because the % is accurate and meaningful and the distance is only a proxy for battery state of charge (SOC). As others said above, use the Energy app to show your current rate of energy use and your expected range based upon your most recent average driving (you can set the distance used for the average at 5 miles, 15, or 30, whichever best suits your situation). Use one of the side panels in the instrument cluster to show the miniature version of the Energy app so you can see your average Wh/mi figure all the time
Once you get a working feel for your Wh/mi (or Wh/km) figures, you will get better at estimating your range.

 

[x4er0]

They did--it's called recommending to people to not do that often.

Not everbody knows this because not everybody reads a manual or are on this forum so my guess is they made it saver than we think.

Ofcourse keeping it charged at 100% without using it isn't healthy for the batteries, i don't do it either but when i charge to 100% that's when i'm going to use it within 30 minutes.

I park my car and go shopping or going for dinner at put it on 90%, when we are almost done then i slide it to 100% and most chargers here in the netherlands are triple phase 16A.