[EdH]

Hopefully to build up a set of data for real life driving range and efficiency, I thought it might be interesting for EV drivers to submit data for journeys or groups of journeys they have made. The idea is to record the miles driven for a 100% charged battery down to 20% with a little extra information such as temperature, weather conditions and driving style. The reason for chosing this approach is that many users will charge overnight to 100% but are unlikely to want to let the charge run down to below 20%.

For example, a recent set of journeys I made in a 40kWh Leaf with 4 trips of 20 miles on A roads and the rest in short journeys on a day when it was around 8 deg gave 97 miles going from fully charged down to 20%. That's probably all the detail needed but it might help collate data if it was presented in a comma separated format so it can be imported into a preadsheet. So for my journeys it would look something like this.

Leaf,40,8,2,97 - where 2 = mixed driving

For other driving situatons 1 = motorway 3 = city 4 = sporty

So, if you think it would be interesting please start adding your 100% to 20% info.

Thanks

Ed

 

[kcrane]

Are you going to use the size of the battery and the distance to work out miles per kwh?

If so, could you avoid worrying about it being 100% to 20% and ask for car type, conditions, driving style and average m/kwh? I know the e-Golf records each journey as distance, average speed and m/kwh.

Conditions can be a tricky one, e.g 8c could be on a calm sunny day, or it could be a wet dark night with a strong wind on the nose

 

[EdH]

This is more about range than efficiency and I wanted to keep it as simple as possible. You are right that wind, rain and other weather conditions will have an effect, but the problem with collating data like this is that it will never be easy to cover all the different journey types and road and weather conditions. By all means put in as much descriptive info into posts as you like, but for the CSV info please keep it simple in the format suggested.

 

[kcrane]

Ah, OK, you specifically want data for a particular charge/use cycle.
SoC has to start at 100% and it has to go down to 20%.
I can't think when I have had those particular parameters in the 3 months I have had the car, but if enough people do, good luck with the analysis

 

[EdH]

That is how I see it at the moment. Charge up to 100% and then note the mileage when down to 20%. This is for consistency. There could be additional data collected but initially it would be most useful to collect the info suggested in the OP. One of the outcomes is to try and get real comparative data for the range of different vehicles.

It is noticeable that when we get into a car at full charge, the GOM presents a predicted "range". It seems to me that this is unreliable.

 

[kcrane]

Hence guess'o'meter!

 

[EdH]

I have a couple of my recent journeys too add.

First one was many short runs with some very fast driving and acceleration to show off to my brother, and one trip of 20 miles. Ave temp 9 deg and fair weather, so

Leaf,40,9,4,92

Next trip was two 50 mile journeys in poor weaher ( wind and rain) and average 9 deg on mainly A roads and motorway at speeds around 50 - 70

Leaf,40,9,1,100

I will have a go at producing some sort of data summary when I've got more journey data - even if it is all mine.

Would like to see something from other makes and models though

 

[MikeProcter]

Very few of my almost 15,000 miles over the last year would fit your criteria.

At the moment I’m charging at Todhills Services on the M6. I started to charge at 25% having covered 90.8 miles on damp roads in temperatures around 7-9c in breezy conditions.

On Tuesday I covered 114 miles during Storm Gareth having passed 1% 6 miles away from the service station.

In my opinion 20% is too prescriptive. It is quite hard with my usage to start charging at 20%.

I charge when I need the range.

I didn’t need to charge today, but arriving back at the holiday cottage with under 10% would mean 18 plus hours to top the battery back up and as I want to tour around the Lakes tomorrow I want a full battery so we can leave early.

 

[kcrane]

In my opinion 20% is too prescriptive.

Agreed, see earlier discussion

 

[EdH]

Yes agreed, I will continue collecting as much data as I can in the format I proposed but if people want to post other similar info but mainly going from 100% to as low a percentage as possible it might be possible to also make use of that data.

The aim though is to collate as much real life info as possible, from hopefully a range of vehicles.

 

[MikeProcter]

What speed do you define motorway driving as? Many EV drivers drive on the motorway st speeds between 55-70mph indicated. This will have a huge difference to how far you can drive.

For instance I drove M25/A3/A3M and back last summer in 32c. 170 miles on one charge. Arrived home with 2%. My speed was 55mph while using ProPilot. Air conditioning was on.

 

[EdH]

If you want to put in additional info into the trip data that is fine. Given I hope to collect plenty of data, it is easier to keep the data simple. So for your trip I would start by writing down the trip as


Leaf,40,32,1,170,100-2

where 100-2 represents the battery start and finish percentages

 

[donald]

The use of the heater is all powerful here, and the number of trips constituting the distance quoted.

If you do one trip of 100 miles and don't use the heater, if you then did exactly the same thing in a series of 10 short hops and running the heater you might not even get 50 miles.

It is a very surprising thing to ex-FFV drivers that heating the cabin takes up so much energy, because they got it for 'free' before, but it's actually a comparable amount of energy to driving the car!

ICE are better heat generators than they are traction power generators!

 

[AnotherJoe]

I used to log mileage, temperature and kWh consumed and for my Soul and then i realised that all this is pointless, once we get to cars with range above 200 miles it doesn't matter, the same as it doesn't matter with ICE cars, you just fill up when you are low and dont obsess over whether the estimated range on your ICE car is super accurate or not.
In your case the "data" collected would be so "dirty" as to be meaningless. There are so many variables you are not capturing that have a major bearing - the speed, whether its wet and how wet, whether the heater is on and to what temperature and for how long, the different efficiencies of different EVs, driving style of individuals, at very best all you'd end up with is showing that range declines as temperature declines and speed increases, and vice versa.
We already know that.

 

[EdH]

Still of the view that this log will provide useful results in terms of real life driving range. If all EV drivers on here added a couple of trips then we could all benefit in terms of seeing what all makes and models can do for real world journeys.

So my latest log entry spread over 4 days last week is - Leaf,40,11,2,102

No need to enter the start and end percentages as this data is for the default 100% to 20%.

 

[EdH]

In case anyone is interested I have a new trip (a no of journeys of varying lengths ranging from 2 to 30 miles) to add. Its warming up generally but I have estimated the average temperature to be 12 deg so this is how the latest log entry looks. - Leaf,40,12,2,111

 

[Astolat]

I agree that it’s a useful project; it seems it is safer to have an idea of how many miles, under different conditions, you can do for each 10% of battery and do a quick bit of mental arithmetic rather than pay any attention to the GOM.

I might have a result to add from time to time, but normally I’m very unlikely to get down to anywhere near 20% - I mostly have local driving and as a Chargemaster subscriber I get free parking at Waitrose in Guildford while charging, so consequently my real difficulty is keeping the SOC from being too high too much of the time.

 

[Hilltop Dave]

For my 24kWh Leaf, I have kept a daily spreadsheet of miles driven and start and finish %SOC (plus any daytime charging).

From this I have calculated monthly averages for %SOC per mile (and fractions of mile per %SOC), which gives me a pessimistic figure for the available single journey range (as most of my driving is multiple 7.5 mile journeys) and highlights a significant seasonal variation.

Having acquired the leaf as a 1 year old ex-demo in Sept 2014, my January 2015 100-20% figures were: Leaf,24,5,2,53
and for July 2015 were: Leaf,24,20,2,71

Now that the Leaf is older and the battery capacity is nearer 20kWh, my July 2018 figures were: Leaf,20,20,2,67 and for January 2019: Leaf,20,5,2,47

As @Astolat says, the easiest calculation is to note the miles achieved that day for each 10% SOC used, and use this to calculate how far the remaining battery capacity will take me - more realistic than the GOM!! I find I need to allow an extra 3%SOC for each 100m of climb, but (providing I do not have to use the friction brakes) I get this back on any subsequent equal descent.

@EdH, if you want the full monthly summary spreadsheet, please let me know.

 

[AnotherJoe]

I find the Soul GoM is pretty good and does what you folks appears to be having to do mental gymnastics to work out. If anything it underestimates.
Plus in any case if you get close to the wire let's say you've got 50 miles to go andbthe GoM says 48 woudl you not slow down until it's showing 51 ? ( If no place to charge enroute. )

 

[AnotherJoe]

Still of the view that this log will provide useful results in terms of real life driving range. If all EV drivers on here added a couple of trips then we could all benefit in terms of seeing what all makes and models can do for real world journeys.
.

Hmmm ... use Donald's results and you'll end up stranded 50 miles from home.