bmw i3 important question

[Deutsch100]

I’m still a bit astounded that there can be such a difference between the range we seem to get from our i3 120Ah - and what others in places that would appear to be more suited to EV driving - do from theirs.
Clearly we’re very fortunate, but I still don’t think we are that unusual in getting that sort of performance from ours...
Here is a an article from a UK EV website that tested the i3 in the real world:

https://www.nextgreencar.com/review/8741/bmw-i3-120ah-review/

Here is what they said in “MPG and running costs” about the i3 (120Ah) and it’s pretty much what we get too...

“ Here we return to the statement at the top of the review, where I said that 'this latest update is perhaps the most significant yet'. The reason for this is because BMW has always previously offered a range-extended version of the i3 - the i3 REX - alongside a pure-electric model. With this latest battery update, it has removed the REX, reckoning that the real-world range is enough for drivers to rely on now.
Considering REX models outsold the pure-i3 two to one in the UK, it's a brave move. With an official range of 192 miles WLTP on a single charge, it looks like it may be a sound one however.

In real-world driving, I found that official figure to be pretty reliable too. With longer stretches of motorway driving, the average range dropped to a little over 180 miles on a charge, and the average by the end of my time with it was 4.5 miles/kWh. That equates to 170 miles on a charge, though routes with a greater mixture of open and urban roads saw the range increase to 193 miles. That's in Comfort mode too, with Eco taking that to 206 miles, and Eco+ to 210 miles.

It says much about the increased range available from the new i3 that I just left the BMW in Comfort the whole time, enjoying the performance on offer and not worrying about charge.”

After some issues with uploading images..
Here's our i3, the range (yesterday in Comfort mode after switch on) and the battery Kapa from a few weeks ago:

VERY impressive!! WOW!!!!

 

[Deutsch100]

I’m still a bit astounded that there can be such a difference between the range we seem to get from our i3 120Ah - and what others in places that would appear to be more suited to EV driving - do from theirs.

The bottom line seems to be low driving efficiency and why Deutsch100's 2.8 mi/kWh is so much lower than what seems to be typical for his situation. He's not a new EV drive still learning how to drive efficiently, so this remains a mystery to me.

Me too alohart. My 2020 i3S is my 4th EV, and I am the master at regen braking, feathering the go pedal, using EcoPro most of the time..... It is BIG mystery to me too!!!

 

[alohart]

My 2020 i3S is my 4th EV, and I am the master at regen braking, feathering the go pedal, using EcoPro most of the time..... It is BIG mystery to me too!!!

It might be time to drive a different i3 to compare efficiencies. Maybe there's another i3 owner in your area.

 

[Fordychap]

I’m still a bit astounded that there can be such a difference between the range we seem to get from our i3 120Ah - and what others in places that would appear to be more suited to EV driving - do from theirs.

The bottom line seems to be low driving efficiency and why Deutsch100's 2.8 mi/kWh is so much lower than what seems to be typical for his situation. He's not a new EV drive still learning how to drive efficiently, so this remains a mystery to me.

Me too alohart. My 2020 i3S is my 4th EV, and I am the master at regen braking, feathering the go pedal, using EcoPro most of the time..... It is BIG mystery to me too!!!

What a great suggestion by @Alohart..
I’m a complete newbie to the i3 so figured that something doesn’t sit right - when @Deutsch100 with a far stronger EV experience isn’t getting the mileage.. I can’t imagine exactly what’s wrong - I don’t know enough about the i3 systems - but for his peace of mind I really hope it works out well soon...

 

[Deutsch100]

Thanks Fordy and Art. I let my i3S "run out" of battery and the REX kick on yesterday afternoon. I plugged my car into my BMW Level II wall charger. Someone suggested this on the Facebook i3 Page. They said to charge on Level II, not the provided Level I and then allow the car to remain on the charger for at least 6 extra hours to allow the batteries to balance. I have no idea if this is a thing, LOL. But, already my range is up to 140 miles, instead of the normal 124-126 I have been getting and it is "cold" here, 47F!

 

[Fordychap]

But, already my range is up to 140 miles, instead of the normal 124-126 I have been getting and it is "cold" here, 47F!

That’s great news and SO glad it’s headed in the right direction... I’ve never used or experienced a REx fitted i3 so have no idea of the idiosyncrasies of this version - but clearly someone helpful in the i3 community does...
As for 47°F being cold - that’s recently been our warmest temperature all year - and it’s been almost shirtsleeve weather!!
Will be pleased when summer finally comes and we can bask in the heat of 66°F or maybe a bit more!!

 

[Deutsch100]

But, already my range is up to 140 miles, instead of the normal 124-126 I have been getting and it is "cold" here, 47F!

That’s great news and SO glad it’s headed in the right direction... I’ve never used or experienced a REx fitted i3 so have no idea of the idiosyncrasies of this version - but clearly someone helpful in the i3 community does...
As for 47°F being cold - that’s recently been our warmest temperature all year - and it’s been almost shirtsleeve weather!!
Will be pleased when summer finally comes and we can bask in the heat of 66°F or maybe a bit more!!

By the time I drove to work this morning, my car had 155 miles on pure electric and in EcoPro it showed 167 miles It seemed letting the battery deplete, run on REX, charge on Level II and leave it plugged in for at least 6 hours past complete charging for a battery balance did the trick!! YAY!

Bask in the heat of 66F, ha ha ha LOL. You would D I E in summer here in Southern California. 90F is considered cool, and many weeks (or months) see 100-110F!!!!

 

[CP361]

My new to me 2018 I3s BEV's GOM list 120 miles in comfort mode at 86% and it is around 48f (8.8c). I look forward to the summer and warmer weather.

 

[Fordychap]

By the time I drove to work this morning, my car had 155 miles on pure electric and in EcoPro it showed 167 miles It seemed letting the battery deplete, run on REX, charge on Level II and leave it plugged in for at least 6 hours past complete charging for a battery balance did the trick!! YAY!

Bask in the heat of 66F, ha ha ha LOL. You would D I E in summer here in Southern California. 90F is considered cool, and many weeks (or months) see 100-110F!!!!

That's fantastic news. Seems like the REx and Level 2 charge sorts that idiosyncrasy out - I can see you doing that a little more often from now on...

As for weather - I'm definitely a northern hemisphere, Viking descended, Westmorland (an old English county) man...
Not only do we still count sheep in the old base 20 way (Yan, tan, tethera) but at anything above 24 degrees Celsius (75 F) and I start to melt fast...
Shirt sleeve weather (when working) here on the farm is anything over 10 degrees C (50 F). I like it cool. I'm not one for cooking myself on a beach...

In the late 80's I spent quite a while in San Diego (about 5 months in total) and remember Mission Bay, the old wooden rollercoaster, OMBAC DTL competitions , cold Pacific Beach (PB) Blonde beer and the girls.... I do remember it was warm, and only seemed to rain at night... Happy memories.

 

[alohart]

By the time I drove to work this morning, my car had 155 miles on pure electric and in EcoPro it showed 167 miles It seemed letting the battery deplete, run on REX, charge on Level II and leave it plugged in for at least 6 hours past complete charging for a battery balance did the trick!! YAY!

The i3's passive battery cell charge level balancing is implemented using resistors that discharge those cells with the highest charge level. This occurs whenever the high-voltage system is off (e.g., when an i3 is off, not charging, not preconditioning). Leaving an EVSE plugged in would only increase the battery pack's charge level if the balance had been so bad that the charge level had dropped during balancing. The balance resistors have such a high resistance that balancing is very slow, so the balance shouldn't have improved noticeably in 6 hours.

The fact that the high-voltage system is typically off most of the time means that cell balancing is almost always occurring. As a result, few i3's likely have battery packs that are significantly unbalanced. Some Android smartphone apps as well as BMW's ISTA+ service software display the maximum and minimum voltages in the battery pack. When some i3 owners have posted screen shots showing maximum and minimum cell voltages, I've never seen much difference in these voltages which means that the cell charge levels have been well-balanced.

What is more likely to have occurred in your case is that the charge level calculation was calibrated when you allowed the charge level to drop to a low level followed by charging fully. This can occur with many rechargeable battery powered devices that calculate charge level using the current flow in and out of the battery. Due to unmeasurable internal self-discharge that occurs with all battery cells, the charge level calculation gradually loses accuracy. Discharging to a low charge level reveals this inaccuracy because the voltage at the low calculated charge level isn't what it should be. The calculated charge level is then reset to be consistent with the voltage. So as with any rechargeable battery powered devices, the charge level should be allowed to decrease to a low level periodically followed by a full charge.

 

[Deutsch100]

By the time I drove to work this morning, my car had 155 miles on pure electric and in EcoPro it showed 167 miles It seemed letting the battery deplete, run on REX, charge on Level II and leave it plugged in for at least 6 hours past complete charging for a battery balance did the trick!! YAY!

Bask in the heat of 66F, ha ha ha LOL. You would D I E in summer here in Southern California. 90F is considered cool, and many weeks (or months) see 100-110F!!!!

That's fantastic news. Seems like the REx and Level 2 charge sorts that idiosyncrasy out - I can see you doing that a little more often from now on...

As for weather - I'm definitely a northern hemisphere, Viking descended, Westmorland (an old English county) man...
Not only do we still count sheep in the old base 20 way (Yan, tan, tethera) but at anything above 24 degrees Celsius (75 F) and I start to melt fast...
Shirt sleeve weather (when working) here on the farm is anything over 10 degrees C (50 F). I like it cool. I'm not one for cooking myself on a beach...

In the late 80's I spent quite a while in San Diego (about 5 months in total) and remember Mission Bay, the old wooden rollercoaster, OMBAC DTL competitions , cold Pacific Beach (PB) Blonde beer and the girls.... I do remember it was warm, and only seemed to rain at night... Happy memories.

I am 100% the same. I am 100% Teutonic myself. Anything above 20-24C and I think it is hot, LOL. San Diego is beautiful, but for So. California standards....very cool and tempered. I am in Calabasas, CA and our June-Oct is usually 33-45C!!! Last August we had several days of 49.5C!!! I thought I would D I E

 

[Deutsch100]

By the time I drove to work this morning, my car had 155 miles on pure electric and in EcoPro it showed 167 miles It seemed letting the battery deplete, run on REX, charge on Level II and leave it plugged in for at least 6 hours past complete charging for a battery balance did the trick!! YAY!

The i3's passive battery cell charge level balancing is implemented using resistors that discharge those cells with the highest charge level. This occurs whenever the high-voltage system is off (e.g., when an i3 is off, not charging, not preconditioning). Leaving an EVSE plugged in would only increase the battery pack's charge level if the balance had been so bad that the charge level had dropped during balancing. The balance resistors have such a high resistance that balancing is very slow, so the balance shouldn't have improved noticeably in 6 hours.

The fact that the high-voltage system is typically off most of the time means that cell balancing is almost always occurring. As a result, few i3's likely have battery packs that are significantly unbalanced. Some Android smartphone apps as well as BMW's ISTA+ service software display the maximum and minimum voltages in the battery pack. When some i3 owners have posted screen shots showing maximum and minimum cell voltages, I've never seen much difference in these voltages which means that the cell charge levels have been well-balanced.

What is more likely to have occurred in your case is that the charge level calculation was calibrated when you allowed the charge level to drop to a low level followed by charging fully. This can occur with many rechargeable battery powered devices that calculate charge level using the current flow in and out of the battery. Due to unmeasurable internal self-discharge that occurs with all battery cells, the charge level calculation gradually loses accuracy. Discharging to a low charge level reveals this inaccuracy because the voltage at the low calculated charge level isn't what it should be. The calculated charge level is then reset to be consistent with the voltage. So as with any rechargeable battery powered devices, the charge level should be allowed to decrease to a low level periodically followed by a full charge.

A-ha. Once again Art knows best and explains it clearly and perfectly. Thank you!!! You are such a valued Member on this page!