Range

[Bedders]

Apologies if this has been covered previously, but I cannot find reference to it.
Under 400 miles driven so far, but I am experiencing repetitive behaviour on the range indication -
The range drops by around 2 miles for every mile driven, regardless of driving style. Anyone else experiencing this?
Granted I have had a few occasions of demonstrating the acceleration.
But in the main, I drive like the old man I am.
I endeavour to get to my destination without use of the brakes.
Range aside, my only other criticism, is that on the motorway, it can be a tad twitchy. presumably caused by the low turning circle and narrow tyres.

 

[TomMoloughney]

Apologies if this has been covered previously, but I cannot find reference to it.
Under 400 miles driven so far, but I am experiencing repetitive behaviour on the range indication -
The range drops by around 2 miles for every mile driven, regardless of driving style. Anyone else experiencing this?
Granted I have had a few occasions of demonstrating the acceleration.
But in the main, I drive like the old man I am.
I endeavour to get to my destination without use of the brakes.
Range aside, my only other criticism, is that on the motorway, it can be a tad twitchy. presumably caused by the low turning circle and narrow tyres.

Please understand the range indication is a 'GUESS' the car makes based on previous driving data it has. It isn't actually the range the car can accomplish because it cannot possibly predict things like the speed you'll be driving, whether or not you'll be driving up long inclines, will you use HVAC system, how well you are at using the regenerative braking system for most of your slowing down and stopping needs, How much weight you'll be carrying, if you'll be driving into a strong headwind, the ambient temperature, etc. All of these factors can drastically manipulate your real range.

You've only driven the car for 400 miles. You are getting to know it and it is getting to know your driving style which is why the guess meter is dropping. I suppose you aren't driving as efficiently as it hoped you would be!

In any event, give it a few weeks and a couple thousand miles and you'll have a good grip on how far it will take you based on how you drive it. Remember whit an EV, speed kills (range that is) and you'll go much further if you can keep your speed under 70mph than you will if you drive 75 to 80mph. Also, be prepared for a significant range drop in the winter. Even with the heat pump you can expect anywhere from a 15% to 25% loss of range when it's below 30 degrees.

EV range is a moving target

 

[amateurish]

So are you starting with a range of about 70-80 miles, but finding that you can only travel 35-40? If so, that doesn't sound good.

 

[TomMoloughney]

So are you starting with a range of about 70-80 miles, but finding that you can only travel 35-40? If so, that doesn't sound good.

How do you come to that? The reports we were getting from the early i3 owners last winter was they were getting about 60 to 65 miles per charge in the dead of winter. That's about what I would expect.

 

[MichiganI3]

I have driven my I3 REX now exactly for 600 mostly electric miles. In mixed suburban driving here in the Metro Detroit area (on and off interstates and express ways) I got so far 70-90 miles on one charge. Speed has indeed an influence on the range, in addition to heavier AC use and transported weight.

 

[RJSATLBA]

I have a recollection of a much earlier post with a similar issue that turned out to be a fault. Might be worth searching or trawling.

 

[amateurish]

So are you starting with a range of about 70-80 miles, but finding that you can only travel 35-40? If so, that doesn't sound good.

How do you come to that? The reports we were getting from the early i3 owners last winter was they were getting about 60 to 65 miles per charge in the dead of winter. That's about what I would expect.

Assuming the range starts at 70-80 on the GOM (that's what I get) if the range dropped by 2 miles for every mile driven, then the OP's actual range would be 35-40?

 

[surfingslovak]

So are you starting with a range of about 70-80 miles, but finding that you can only travel 35-40? If so, that doesn't sound good.

How do you come to that? The reports we were getting from the early i3 owners last winter was they were getting about 60 to 65 miles per charge in the dead of winter. That's about what I would expect.

Assuming the range starts at 70-80 on the GOM (that's what I get) if the range dropped by 2 miles for every mile driven, then the OP's actual range would be 35-40?

I would not automatically assume that. I would ask the OP to consume 25% or 50% of usable battery capacity, as measured by the four large bars on the dash, and record the distance driven since last full charge via the trip meter. It should be easier to extrapolate the total range of the vehicle from that than from the opaque guessometer algorithm.

 

[roperld]

I think BMW has much to worry about with the Mercedes B-Class Electric Drive having 87-miles and 104-miles ranges: http://insideevs.com/mercedes-benz-b-class-ed-battery-larger-expected-36-kwh/#comment-478705

 

[noakey]

How do you come to that? The reports we were getting from the early i3 owners last winter was they were getting about 60 to 65 miles per charge in the dead of winter. That's about what I would expect.[/quote]

Assuming the range starts at 70-80 on the GOM (that's what I get) if the range dropped by 2 miles for every mile driven, then the OP's actual range would be 35-40?[/quote]
I would not automatically assume that. I would ask the OP to consume 25% or 50% of usable battery capacity, as measured by the four large bars on the dash, and record the distance driven since last full charge via the trip meter. It should be easier to extrapolate the total range of the vehicle from that than from the opaque guessometer algorithm.[/quote]

I think extrapolating from a short drive is misleading.. sometimes m y BEV starts at reading 91 miles full, then plumets to 60 as a move off from cold... then recovers back to 85 ish during the journey (then of coarse drops away pretty accurately).

I suggest starting from full with departure time (so batteries are pre-conditioned), then drive and drive and drive until you get to say 20%. The extrapolate the reminder. My 74 mile run to work often extrapolates out to a total range of 99 miles.

 

[Surge]

So are you starting with a range of about 70-80 miles, but finding that you can only travel 35-40? If so, that doesn't sound good.

That's about the same as I predicted, and I posted a spreadsheet on the topic in an earlier post. This very low range would occur if you combined 75mph driving in cold temperature! and with a deteriorated battery. Note that we don't don't how long the battery will take to deteriorate. It shouldn't be an issue, but no one knows. I factored a 30-% reduction because below that BMW will replace it under warranty.

 

[surfingslovak]

It shouldn't be an issue, but no one knows. I factored a 30-% reduction because below that BMW will replace it under warranty.

It won't be an issue in Toronto due to the cold climate. I would budget about 5% a year with average annual kilometers. More if driven excessively. Degradation will slow a little bit over time.

 

[Surge]

Thanks, but I meant combining the factors:

- highway (~75mph) range is about 60 miles
- cold range -25%, so now you're at 45 miles
- battery degradation -5% - -30%, so you're now at 32-43 miles

It's all a moving target, as Tom said. Eg, there's no regen included above, and you're probably not going to drive at 75 mph constantly. And if you knew you would push the range, you would adjust your driving to maximize it.

 

[jadnashuanh]

Battery temperature conditioning and the initial cabin conditioning can put a fairly big dent in the available charge and resulting maximum range. For maximum range, do that before you leave while still plugged into prime power. Lots of short trips with long rests that could allow the vehicle to either heat up or cool down significantly, will shorten the range since you'd be doing that much more often. Ideally, you'd precondition before leaving each time, or not make long stops so things won't need a full drain to get ready again.

There are huge differences in how people drive and where they drive, so until the car has a chance to learn your typical patterns, the range estimate will be only representative of an average...not customized for you. My guess is that this will take more than a couple of miles.

 

[surfingslovak]

- highway (~75mph) range is about 60 miles
- cold range -25%, so now you're at 45 miles
- battery degradation -5% - -30%, so you're now at 32-43 miles

Yes, certainly, but these are best guesses and estimates. It's tough to get reliable data. For me, this means even more reason to get the REx.

There are huge differences in how people drive and where they drive, so until the car has a chance to learn your typical patterns, the range estimate will be only representative of an average...not customized for you. My guess is that this will take more than a couple of miles.

Interesting, that's a fair point. I'm not sure how much I would trust an opaque algorithm, such as the guessometer.

 

[Gonville]

I don't think it is so "opaque".

On the ICE car the range estimate alters in a similar manner. It purely uses tank capacity, SOC in this case, divided by the average consumption so far. As far as I can see it extends that as soon as you start driving more economically than your previous average. If you rag it the range drops as your current journey consumption exceeds your average. So the only factors it is using are the ones that it has. Capacity, average life consumption and current trip consumption. I don't believe it's using anything else such as temperature or as in ICE case altitude or temperature for example.

 

[surfingslovak]

I don't think it is so "opaque".

On the ICE car the range estimate alters in a similar manner. It purely uses tank capacity, SOC in this case, divided by the average consumption so far. As far as I can see it extends that as soon as you start driving more economically than your previous average. If you rag it the range drops as your current journey consumption exceeds your average. So the only factors it is using are the ones that it has. Capacity, average life consumption and current trip consumption. I don't believe it's using anything else such as temperature or as in ICE case altitude or temperature for example.

If the algorithm was indeed this simple, and it only multiplied the remaining battery charge with the average energy economy, I would be very happy. This is unfortunately not the case. Virtually every automaker includes some type of "heuristics", or secret sauce, to determine the magic number of miles of range remaining. I spent months agonizing over the far simpler algorithm in the LEAF before giving up. While the estimated range figure could be made bullet-proof, there is presently no such solution on the market.

None of the heuristics consider things like changing air density (aerodynamics plays a big role in freeway commuting) or instantaneous temperature (both of the air and the battery). Virtually none consider the effect of elevation change. While some might find the guessometer comforting, and reassuring, I do not, and would prefer a much simpler percentage display of state of charge.

Even Apple offers that on their products, as a user-configurable option, and they arguably agonize over such things, and try to make technology as accessible and easy as possible. I'm sure that the guessometer will improve in the future, but in the meantime, every OEM will be well-advised to include a state of charge indicator in percent. It's easily done, and unobtrusive. Given the current state of technology, the is no excuse for not including it.

 

[Gonville]

If the algorithm was indeed this simple......

Even Apple offers that on their products........

I don't disagree. Just that it uses what it has......and none of that clever stuff like temperature and density of air as you say. It is not solely SOC divided by average. But previous average and current consumption. It's as reliable as the SOC guess meter.

As for Apple. It's absolutely true that I can rely 100% on the SOC in my Apple product to know how long it is before it goes flat. LMAO. It's a variable. Depends on rate of consumption - same. Only thing I know is the 'range' is short on my iPhone. I know it won't last a day if I have everything turned on. A SOC doesn't help me as it shuts off at 10%. Then the last 1% on call can last 20 minutes or more if you turn it on after it powered off at 10%. Doh.

I think both methods give you a "false" illusion of being in control. Some people prefer one some the other.

 

[surfingslovak]

Just that it uses what it has.

I will watch it more closely then. I was under the impression that it was factoring in a bit more than just previous average energy economy.

and none of that clever stuff like temperature and density of air as you say. It is not solely SOC divided by average. But previous average and current consumption.

Many consumers new to EVs have the expectation that the range estimate is going to be accurate. Down to the last mile. The clever stuff will be unfortunately needed, if we don't want to fall short of that expectation.

It's as reliable as the SOC guess meter.

It very well might, even though my initial expression was different. The point of an SOC is that it can be used for purposes other than range prediction. There is no need to dumb down in-car instrumentation this much. Particularly not when an SOC indicator is considered perfectly adequate in consumer electronics, and even product designers at Apple don't dare to completely dispose of it.

As for Apple. It's absolutely true that I can rely 100% on the SOC in my Apple product to know how long it is before it goes flat. LMAO. It's a variable. Depends on rate of consumption - same. Only thing I know is the 'range' is short on my iPhone. I know it won't last a day if I have everything turned on. A SOC doesn't help me as it shuts off at 10%. Then the last 1% on call can last 20 minutes or more if you turn it on after it powered off at 10%. Doh.

With all due respect, how long have you owned an EV?

While this might apply to you, many others found an SOC indicator quite useful. With an EV, you can trade range for speed, and even though a simple percentage indicator is not the best way to approach this, it allows for better planing than some amorphous estimated mile number.

I think both methods give you a "false" illusion of being in control. Some people prefer one some the other.

While you might not be completely aware of how to effectively save energy and extended the useful remaining capacity of the battery on a smartphone, your EV readily allows that. Slowing down has a profound impact on energy consumption, and it puts the driver very much in control.

Here is a related discussion we had on the topic on the Tesla forum:

I want to see a numeric representation on on EV's. Not bars, faux fuel gauges, batteries, etc. A simple numeric value of the state of charge percentage is so much better.

Agreed. I would love to see a kWh estimate somewhere as well, if possible, much like what GM does in the Volt. Nissan has already confirmed that the 2013 model year LEAF will contain an SOC gauge in percent. Kadota-san directly attributed this change to a meeting held at Google last December. You can see nearly all LEAF owners in attendance voting in favor of adding an SOC gauge, which was dutifully implemented by Nissan in 2013 model year (and later) vehicles.

 

[DerfSdrawd]

The phone app shows % SOC.

On a recent trip to London in my i3 BEV I started with a full charge range indicated on the car of 85 miles, then did 36 miles 75% of which was on motorway, keeping to 65mph and using Eco pro+. The app showed SOC of 65% after I reached my destination, suggesting that driving that way produced a range of c102 miles (36/0.35). At this point the car showed a range of 55 miles.

I suppose I used that data to work out that I could get home without recharging. Plus the car did 36 miles but only used 30 miles of the initially indicated range. So I did 70-75 mph on the way back, had to do a 6 mile detour and arrived home with 8 miles indicated range, app showing 10% SOC and a trip of 80 miles since the last charge.

Temperature was c20 Celcius. I got the car in April and have done c4k miles now. Haven't experienced very low temperatures (yet), but clearly driving at higher speeds chews up battery capacity.

I find that the combination of increasing experience, the car info and the app info is making me more confident in the range indicated and I guess most importantly, how my driving style will affect the remaining range. So I'll enjoy the blast on short trips and unleash my inner pensioner on longer ones.