My Black Beauty, i3 94Ahr Rex

[Clanduncan]

I've owned a '66 plate 2017, 94Ahr Rex for three years now. In this time I've seen the seasonal variance in range, from 100 to 135 miles electric, and 70 to 100miles on the Rex. My personal record for distance, without the Rex cutting in, is 132 miles with 9% battery still left. I drive evenly, and get an average 4.5miles / kwhr. In three years I've not seen any noticeable degradation in range, despite passing 88,000 miles, with the battery still reporting a kappa max of 27.6-28.2kwhr. I only charge to 100% when I need to, via Intelligent Octopus, usually setting a charge limit of 90%, which generally finishes at 85-95%. With the Rex option I have no range anxiety, but the option of travelling up to 220 miles without a recharge if I want to.

My improvement(s) have been;- (1) a larger 10.25" screen to replace the smaller 6.6" unit, sourced via AliExpress, fitted and coded myself for under £370, (2) all front lights (dip, high, side, indicator) are now LED as opposed to tungsten, with no additional electronics needed.
I considered (a) lowering springs, and wheel spacers to enhance handling, but it drives so well that I decided not to fit the springs, but kept the 15mm spacers, (b) sequential flasher lights for the wing mirrors, but was advised by an independent specialist that the electric mirrors can be fragile and break when changing bulbs, so haven't fitted those, (c) I looked at Havrla’s upgrades to a 120Ahr battery in the Czech Republic, which paired with a Rex should give a range of over 250 miles in summer. The guy is fantastic at what he does, but the costs are understandably so high, that if I ever had to replace my i3 battery it would probably be cheaper to get another 2nd hand i3 instead. What an adventure that would be though, upgrade and holiday all in one!

The wheels are original 'pizza' alloys, which I don't plan to change. I reckon the flatness of design is probably more aero efficient. Maybe I'll get them cleaned and refurbished at some future point, perhaps changing the colour to black, to match the rest of the car.

The only disappointment for me has been the poor radio reception on both FM and DAB. So, now I just use the usb socket for my own music, and rarely listen to the radio.

Three years after buying it, I'm still finding out features I didn't know about. Overall I wouldn't change this car for the world, and I certainly wouldn't go back to an ICE car.

 

[Clanduncan]

Upgraded 10.25" screen. Coded with my VeePeak ODB2 Bluetooth adapter, and a licensed copy of the Bimmercode app.

 

[Clanduncan]

Approaching 8 years old, and this is my HV battery health status after the most recent full charge. If you look at the figures, the SOC and SOH figures are very close to each other. Does that suggest that the battery is in near full health? Or does dividing battery capacity by rated capacity 87/94 seems to suggest over 92% available. Either seems like a very good figure to me at this point.

 

[JamesInLondon]

Also have a 66 plate 2017 Rex and am very interested in learning what is involved in changing the lights from tungsten to LED.

I've owned a '66 plate 2017, 94Ahr Rex for three years now. In this time I've seen the seasonal variance in range, from 100 to 135 miles electric, and 70 to 100miles on the Rex. My personal record for distance, without the Rex cutting in, is 132 miles with 9% battery still left. I drive evenly, and get an average 4.5miles / kwhr. In three years I've not seen any noticeable degradation in range, despite passing 88,000 miles, with the battery still reporting a kappa max of 27.6-28.2kwhr. I only charge to 100% when I need to, via Intelligent Octopus, usually setting a charge limit of 90%, which generally finishes at 85-95%. With the Rex option I have no range anxiety, but the option of travelling up to 220 miles without a recharge if I want to.

My improvement(s) have been;- (1) a larger 10.25" screen to replace the smaller 6.6" unit, sourced via AliExpress, fitted and coded myself for under £370, (2) all front lights (dip, high, side, indicator) are now LED as opposed to tungsten, with no additional electronics needed.
I considered (a) lowering springs, and wheel spacers to enhance handling, but it drives so well that I decided not to fit the springs, but kept the 15mm spacers, (b) sequential flasher lights for the wing mirrors, but was advised by an independent specialist that the electric mirrors can be fragile and break when changing bulbs, so haven't fitted those, (c) I looked at Havrla’s upgrades to a 120Ahr battery in the Czech Republic, which paired with a Rex should give a range of over 250 miles in summer. The guy is fantastic at what he does, but the costs are understandably so high, that if I ever had to replace my i3 battery it would probably be cheaper to get another 2nd hand i3 instead. What an adventure that would be though, upgrade and holiday all in one!

The wheels are original 'pizza' alloys, which I don't plan to change. I reckon the flatness of design is probably more aero efficient. Maybe I'll get them cleaned and refurbished at some future point, perhaps changing the colour to black, to match the rest of the car.

The only disappointment for me has been the poor radio reception on both FM and DAB. So, now I just use the usb socket for my own music, and rarely listen to the radio.

Three years after buying it, I'm still finding out features I didn't know about. Overall I wouldn't change this car for the world, and I certainly wouldn't go back to an ICE car.

 

[Clanduncan]

If your rear lights are LED already, then you should be able to swap front lamps over without any problems whatsoever. It was a straight swap for me, without any flasher problems. Headlamps too, and two out of three front lamps accessed behind a cover in the front wheel wells.

 

[alohart]

If you look at the figures, the SOC and SOH figures are very close to each other. Does that suggest that the battery is in near full health? Or does dividing battery capacity by rated capacity 87/94 seems to suggest over 92% available.

It seems pretty straightforward that 87.3% SOH indicates that your battery pack has lost 12.7% of its new nominal usable capacity. However, I don't understand the reported maximum actual SOC, 85.3% in your case, because your cell voltage at a full charge, 4.13 V, is what it would have been when your battery cells were new. The actual SOC is likely the same as it would have been when your battery pack was new with the BMS assuming that the energy corresponding to 1% SOC has remained constant over time which isn't true. Adding the 12.7% capacity loss to the reported current actual SOC, 85.2%, would approximate the current actual SOC, 97.9%. That seems a bit high, but all of these values except for voltage are calculated estimates, so there is almost certainly some error in these values.

 

[Clanduncan]

Alohart;- I had been assuming the BMS buffers which lock away 15% of the battery (assumed 7.5% at top and bottom) was a factor. The figures seemed too coincidental otherwise. The battery was at 100% as reported by the car.
I'm more than happy with the battery health, and not particularly worried about the future capacity. If I was, I'd take it to Havlra in the Czech Republic to have an upgrade!
Thanks for your input, it's been informative to have this discussion, as it's increased my knowledge on the car.

 

[Clanduncan]

An up to date look at how effective (efficient?) such a unique car can be. This is mine after the last three months of usage. The trip computer is reset every 3 months or so, with these figures being the spring ones. Mostly urban driving, with a handful of longer trips, and/or motorway (60mph) journeys included.

 

[Clanduncan]

So, a note here to help other users who might have this issue, or who might get it.

I recently lost all remote connectivity with my car. As a consequence I was unable to use intelligent charging, and had to rely on a manual timer. I also could not send remote commands, and the app did not get updated by the car. After downloading and installing updates, forcing the car itself to look for updates, nothing had changed. I still couldn't communicate with the car.

After some searching around on the web I came across the solution on a Reddit site, and it works by rebooting the car's telecoms module. All credit goes to Reddit user Agentimi for posting this solution. It's pretty simple, only takes 15-20 minutes and worked like a charm. So, the link below is for anybody else who comes across this issue.

 

[Clanduncan]

A minor amount of vinyl wrapping here. I was lucky enough to get an extra set of these dash panels off eBay for less than £12 delivered. Practised on them with some vinyl wrap, just to give the interior dash some extra understated interest.

 

[Clanduncan]

Finally got the wheels refurbished, and I think it just gives the car that extra appeal. You know the saying 'less is more', this I reckon gives an impression of so much more, without explicitly saying it. See what you think from before (silver) to new (gloss black) on the wheels.

 

[Dutchi3]

Nice, works very well on a black i3. On a white i3 I prefer the silver ones.

 

[Candece]

How much does it cost to get done?

 

[mfogarty]

I'm thinking of going black on my 20" 430 wheels. Car looks fantastic, good job!

 

[Clanduncan]

Thankyou everyone. The work was done by 'The Wheel Specialist' in Nottingham, and took just two days from delivery of car to picking it up again (link below). They have several branches round the country, including Leeds. A full strip, refurbish, and recoat in gloss black, was just £564, including new valve stems (the TPMS sensors didn't need replacing). It goes without saying that they rebalance the wheels after refitting the tyres.

https://www.thewheelspecialist.co.uk/

 

[Clanduncan]

A reset trip computer showing data from my recent 520 mile road trip. Majority at 60mph, but the average is dragged down by some urban driving. Overall quite pleased with the efficiency, which is only just less than my usual urban average of 5.0-5.2 m/kwhr.

 

[mfogarty]

5.2 is simply stunning. I wonder if 6 is possible in this car? I should think that would be near to a miracle!

 

[Clanduncan]

That would be nice!
I think my roadtrip figure would have been higher, and closer to my usual average, if it hadn't been for a significant portion of the trip with rain/spray. This last I know affects range downwards.

 

[Michael Otto]

A reset trip computer showing data from my recent 520 mile road trip. Majority at 60mph, but the average is dragged down by some urban driving. Overall quite pleased with the efficiency, which is only just less than my usual urban average of 5.0-5.2 m/kwhr.

Nice job. What settings do you use (comfort, EcoPro, etc?) was the a/c in operation? Where do you live and what was the outside temp?

I live in Florida and my 2018 BMW i3s Rex struggles to stay at 4.0 mi/kwh in the summer.

 

[mojo]

I wonder if 6 is possible in this car?

Yes, easily - the catch is that you have to drive slowly! There was someone on the UK FB group showing an average of 6.1mi/kwh - his average speed was just 16.1 MPH during the 18 mile journey. There was no trickery involved - he was simply driving as you would normally expect during the day in the suburbs of London...