Have had my i3 Rex for just over a week now and while its a great car I've been hugely disappointed with the range I can achieve. I drive 18 miles each way to work, a mix of country lanes, B roads and a few miles on the M3 motorway, largely in light to no traffic. I drive in ecoplus mode, cap my speed at 70mph and have been accelerating gently for the last few days. I run my heater fan on the lowest speed with aircon off. Despite this my best range so far is 59 miles from a full charge and my average is 54 miles! I genuinely thought with 36 miles a day I would be charging every other day maximum yet here I am having to mess about with my 6 metre cable out on my driveway every single night (no garage, untethered heavy cable due to distance from drive to house). I really didn't expect this and I'm wondering what on earth I am doing wrong. All tips gratefully received as I don't think I will be bothered to keep the i3 if it continues like this. I knew it had limitations but 54 miles per full charge is a joke.
Disappointed with range
- Thread starter PipPip
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Dee123
Well-known member
Do you precondition before each trip? It's been cold for the past week and that affects range especially since ReX has no heat pump
Dunkster
Member
Check your tyre pressures too.
noakey
Well-known member
PipPip said:
Hmm you should get a comfortable 80 miles driving how you describe. My only note is that 70mph on the motorway is battery zapping. Stick to 60mph and it makes a huge difference. My commute is 56 mile round trip about 40 is motorway... i reliably get home with 30 miles left on the clock...
Make sure you set departure times and preheat. Make sure your heating is set to ecopro... drive in ecopro. Accelerate gently and anticipate as much as possible.
Hope this helps...
HomelessDude
Member
I would be thinking battery or battery charging problem. I'm getting 84-87 miles per charge in a fully loaded REX with a/c running the whole time.
Does this include motorway? Mines a company car so it wont be a problem getting it looked at and having a loan car. I am suspecting I might have a battery issue.HomelessDude said:
Edit. Should have said the app is scoring me 60 to 70 driving efficiency and normally 4 stars for anticipation plus high recuperation scores so I know my driving style has been conservative. Despite this, still only 59 miles of range max.
BrianStanier
Well-known member
A score of 60-70 is hardly conservative. I would consider 80-90 to be so. I'm not sure what a high regeneration score suggests.
SDCAi3
Active member
Are these numbers actuals (you've run the battery down from a full charge and drove those miles) or based on the range meter? The range meter, otherwise known as the "guess-o-meter" or GOM, is often reported to be very inaccurate. Mine rarely shows more than ~65 miles at a full charge, even after several charges and driving in EcoPro+ mode and driving very conservatively. The longest distance I've gotten out of a charge is now 104 miles and still had 4% state of charge (SOC) according to the mobile app. After charging to 100% that day, the GOM only said 68 miles. I've learned to ignore it and just assume each of the four charge indicator bars will give me 25 miles if I drive like my mom, 20 miles with normal-ish driving, and 15 with fast accelerations and/or high freeway speeds.PipPip said:
SDCAi3 said:
Hmm, I based this on miles driven since last charge plus range the car says I have left (the guessometer I suppose). I've generally been recharging when the guessometer says I have under 35 miles as I need 36 to get to work and back. Your post is extremely interesting and helpful. I will try ignoring the guessometer and see what I get.
ultraturtle
Well-known member
Running the climate control at all could well be the problem.PipPip said:
I'll assume you live and drive in the UK (please update your location in the User Control Panel) and that it has been a bit chilly of late. If you have seat heaters use them, turn off the climate control completely (fan off), and wear gloves if necessary. Seat heat is far more efficient than trying to heat the ambient air of the entire vehicle using the climate control's resistive heating element.
Note that the lowest temperature setting available with the climate control engaged is 60 degrees F, so if you are setting out on a sunny 40 degree day, if the fan is on, the climate control is using gobs of electricity to provide initial resistive heating that you probably do not want, as the sun will quickly heat the car beyond a comfortable level
Just so you know, this thread is about to be inundated with posts from BEV owners gloating over the efficiency of their heat pumps. We REx owners did not have that option, as the gas tank takes up the volume uses for guts of their heat pump systems.
As it gets colder out, (breakeven being about 40 degrees F) heat pumps loose efficiency to the point that both BEVs and RExs are reduced to pretty much the same energy draw to heat not only the cabin, but the battery pack. At this point, crank up the climate control, and accept the inevitable loss of range.
HomelessDude
Member
PipPip said:
About half of the miles are driven at speeds of 55mph-65mph, the rest are a mix of city and secondary roads. My average speed per charge is a bit over 45mph according to my trip computer. Driving conditions are very consistent, temperatures are normally 75 to 85° Degrees and clear dry roads always in Eco-pro. My app shows I'm averaging 4.5 miles per kilowatt over the last 1,000 miles.
jadnashuanh
Well-known member
No idea of the efficiency of the BEV's heat pump, but the advances in heat pump technology in just even the last 5-years is quite impressive, with some home units working quite well at below zero F levels, some producing decent heat at -10 to -15 F. I'd guess that the i3's is designed to work quite well at colder temperatures as BMW did test the vehicle in northern Scandinavia, Canada, and elsewhere where it gets quite cold. The EPA in the USA testing on cold did show a decrease in range at cold, but it was still not all that bad. Resistive heating gives you one watt of heat for one watt...the heat pump on the i3 is still probably at least 2-3x as efficient at low temperatures than that, can could be even better when it is warmer out. Drive with passengers...they put out lots of extra heat!
It's time for those in Sweden and Finland to pop in, even though there weren't that many sales last winter, to chime in with their results. There will be lots of people in the US that will have results over the next few months. It may be premature to make assumptions. The i3 is the first, all-electric from the ground up design that is highly focused on efficiency. One would hope, BMW did their research.
It's time for those in Sweden and Finland to pop in, even though there weren't that many sales last winter, to chime in with their results. There will be lots of people in the US that will have results over the next few months. It may be premature to make assumptions. The i3 is the first, all-electric from the ground up design that is highly focused on efficiency. One would hope, BMW did their research.
ultraturtle
Well-known member
There are in fact advanced technology home units that do quite well even somewhat below freezing. From http://energy.gov/energysaver/articles/air-source-heat-pumpsjadnashuanh said:
Problem is the weight and volume to accommodate the complexity of variable speed, multiple cylinder primary and back up booster compressors and large surface heat exchangers. Not likely for a unit the size of a 2.4 gallon gas tank. The BMW i3 heat pump option is basically an enhanced version of the refrigerant system included on all i3s with a bit more capacity.
From page 43 of BMW's Heating and AC Systems training document:
When I got in the car this morning it was fully charged and the guessometer indicated 55 miles of electric range. This morning I decided to try to do everything I could to optimise performance as a test:
- I preconditioned before departure (which was very nice given it was -1c and our other cover had a thick layer of ice!)
- I took a slower B road route to work which meant typical speed range of 20 to 40mph
- I switched off the fan and put the car in ecopro+ mode so that I drove with ice cold feet
- lights and radio were off. Basically I had no auxiliary power use
- I drove like a grandma, extremely gentle acceleration to the point that a car nearly went into the back of me at a roundabout!
- I kept to the speed limits or below! anticipated and didn't use the actual brake once.
I arrived at the office with 78% charge after the 16 miles suggesting a range of just under 73 miles driving in this extreme manner. Surely there is something wrong guys, this cannot be right?!
- I preconditioned before departure (which was very nice given it was -1c and our other cover had a thick layer of ice!)
- I took a slower B road route to work which meant typical speed range of 20 to 40mph
- I switched off the fan and put the car in ecopro+ mode so that I drove with ice cold feet
- lights and radio were off. Basically I had no auxiliary power use
- I drove like a grandma, extremely gentle acceleration to the point that a car nearly went into the back of me at a roundabout!
- I kept to the speed limits or below! anticipated and didn't use the actual brake once.
I arrived at the office with 78% charge after the 16 miles suggesting a range of just under 73 miles driving in this extreme manner. Surely there is something wrong guys, this cannot be right?!
Boxbrownie
Well-known member
Seems a drop into the local dealer is in order, maybe the Genius chap can shed some light or fob you off? :?
noakey
Well-known member
PipPip said:
Hi... i did an experiment with your query in mind and did everything you describe above...
I left home with 100% charge and 71 miles range indicated with ecopro+. .. i drove 26 miles and arrived with 75% charge left with a range of 62 miless estimated.
This suggests 88 miles range (62+26) or 104 mlies range (26 miles per 25% charge used).
Hooe this helps.
noakey said:
Thanks, your 104 mile range is directly comparable with my 73 mile range for similar set up and driving. That is a massive gap. I think I will have to send my car back for assessment.
Edit. Just looked at my app and driving in extreme economy mode as described above my consumption is still only 3.7 miles/KW, which is the best figure I've achieved for my car, yet still very poor.
BrianStanier
Well-known member
The indicated range is only an estimate. There are two ways of getting a better figure. Either start with 100% and drive until the car stops. Or use the trip m/kWh figure for a reasonable length of typical journey and multiply by the usable battery capacity of 18.8 kWh.
Until the cold weather arrived our overall consumption from taking delivery of the Rex in April was 4.6 m/kWh indicating a range of 86 miles. This we achieved easily. Now the cold weather has arrived consumption has increased and we are only getting 3.7 m/kWh which is 70 miles.
This range reduction of about 20% is close to that we experienced with the Leaf. It is to be expected.
Your figure of 50 is low. But the guessometer may be biased by the last few miles you did. Try either of the above methods to find the real range.
For comparison the app says that the average consumption of all i3s is 3.6 m/kWh - a range of 67 miles.
Until the cold weather arrived our overall consumption from taking delivery of the Rex in April was 4.6 m/kWh indicating a range of 86 miles. This we achieved easily. Now the cold weather has arrived consumption has increased and we are only getting 3.7 m/kWh which is 70 miles.
This range reduction of about 20% is close to that we experienced with the Leaf. It is to be expected.
Your figure of 50 is low. But the guessometer may be biased by the last few miles you did. Try either of the above methods to find the real range.
For comparison the app says that the average consumption of all i3s is 3.6 m/kWh - a range of 67 miles.
Firebird23
Member
- Joined
- Jun 27, 2014
- Messages
- 13
Hi There,
the range algorithm is not supposed to be understood by customers
It in fact uses
- data from last drives
- actual driving behaviour
- navigation data (if routing is active)
- environmental conditions
- ...?
into considerationg to give you a number you don't understand, but that still is quite precise if none of the above parameters is changing while drive...
the range algorithm is not supposed to be understood by customers
It in fact uses
- data from last drives
- actual driving behaviour
- navigation data (if routing is active)
- environmental conditions
- ...?
into considerationg to give you a number you don't understand, but that still is quite precise if none of the above parameters is changing while drive...
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