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I've been looking for a way of getting diagnostic data from the i3 for a while, and just couldn't find anything that worked. Finally today I managed to get a setup working. I'd thought I'd share how as when I was looking there was very little information out there.

The key bit of software is an Android App called Deep OBD for BMW and VAG. You need an OBD adaptor. I went with a bluetooth one that looks very much like the one on this page. It's a bit slow, but it works.

Setup is mainly a case of following the on screen instructions. I paired my bluetooth dongle before hand, but not sure that was necessary. You need to "Generate" a configuration. You'll be taken to a largely blank screen with a "Read" button at the top. You press that and it will ask you which device you're using. Then it will read data from the car, and give a list of modules. It's then a case of going through each one and enabling the items you want to see. The interesting modules on the i3 are:
  • SME - The battery management system
  • KLE - The battery charging logic
  • EME - The drive chain
A couple of screen-shots off my tablet to show the sort of thing I'm now able to view. It's rather similar to ScanMyTesla which Bjorn Nyland uses in his videos, if you ever watch him.

https://dl3.pushbulletusercontent.com/2PypAFFukRNw5aMbs8qjdMloMS4pcxfV/Screenshot_20200216-212031.png



https://dl3.pushbulletusercontent.com/zAYpePqqoTx869kz3TZOIMB5sgmifOgV/Screenshot_20200216-212136.png


A couple of gotchas:
  • You need around 3GB of spare space on your device to download and decompress the data files for this program.
  • Locking the car from outside whilst it is working trips the Alarm. Apparently the alarm is set off by "improper use of the on-board diagnostics port". It's in the manual.
  • Enabling lots and lots of things to read seems to cause problems. You're best keeping the number of values you want to a reasonable number.
A few things I've learnt so far:
  • The SoC displayed on the dash is different to the SoC tracked internally. There appears to be 11% at the bottom and 10% at the top of my battery held in reserve.
  • The two on-board chargers are differnt to each other. One can take a single phase up to 16A, and the other can take two phases of 16A. If you're 32A single phase charging both chargers take 16A off one phase.
  • The motor runs at about 1000rpm per 10mph.
You can log data to a file which I've managed to load up in a spreadsheet afterwards although the sample rate is quite low, so probably best used for looking at trends over minutes and hours rather than seconds. I expect I'll log some charging sessions and some long drives and see if anything interesting comes out. My end goal is trying to get better modeling data into ABRP for planning journeys.

Obviously stuff like this isn't for everyone, but it looks like a useful tool if you want to learn more about how your car works.
 

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This is great, have you found anything that is Apple IOS compatible?
The most interesting bit of information is the 10% buffers at the top and bottom end. Explains why the car is always charged to 100% where as Tesla effectively allows you to adjust the maximum charge level and most people set this to 90% to prolong the battery.
The other thing I am interested in is the battery temperature after a pre-heat. Is it 11C ? or does it get higher?
 

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The most interesting bit of information is the 10% buffers at the top and bottom end.
You seem surprised. The fact that there is bottom and top protection on the i3 battery has been well documented since the first i3 arrived in the UK. For example, the i3 120Ah model has a battery capacity of 42.2kWhs and a usable capacity of 37.9kWhs. An important thing to note is that the battery warranty is based on the usable capacity. It follows that in the case above, the total battery capacity has to fall to below 70% of 37.9 or to 26.53kWs: a reduction in battery capacity of 37.1%. Clearly, BMW has every confidence in the fact that this will not happen.

An important point worth considering is whether repeated charging to 100% SOC is doing the battery any long-term damage? Clearly, it is or there wouldn't be any need for a battery warranty. The bit that most people never see is the fall in total battery capacity over time, and for owners that keep the car for 3 years and then ditch and switch it probably doesn't matter.
 

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You seem surprised. The fact that there is bottom and top protection on the i3 battery has been well documented since the first i3 arrived in the UK. For example, the i3 120Ah model has a battery capacity of 42.2kWhs and a usable capacity of 37.9kWhs. An important thing to note is that the battery warranty is based on the usable capacity. It follows that in the case above, the total battery capacity has to fall to below 70% of 37.9 or to 26.53kWs: a reduction in battery capacity of 37.1%. Clearly, BMW has every confidence in the fact that this will not happen.

An important point worth considering is whether repeated charging to 100% SOC is doing the battery any long-term damage? Clearly, it is or there wouldn't be any need for a battery warranty. The bit that most people never see is the fall in total battery capacity over time, and for owners that keep the car for 3 years and then ditch and switch it probably doesn't matter.
My surprise was more that it was 10% bottom and top. Wondered if there was less at the bottom than the top.
I wonder if battery damage may be more associated with Rapid Charging. It seems that Tesla are now using a further software limit on charging speed over time. So perhaps the warranty assumes continual rapid charging - who knows ?!!

I have bought my vehicle as my intention is to keep it for a few years. What does concern me is that my friends with 3 year lease vehicles just don’t care. With Tesla’s they just charge to 100% all the time and rapid charge all the time no thought about battery care. There will be a lot of suboptimal lease vehicles on the market eventually.
 

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Do these SOC margins reduce as the battery pack degrades in order to maintain the usable value or are they fixed?
 

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Discussion Starter #7
The other thing I am interested in is the battery temperature after a pre-heat. Is it 11C ? or does it get higher?
No idea as yet. I've literally spent a couple of hours with it so far. The battery was at ambient, and I went for a 10 mile drive before snapping that screenshot.

@Weebull My questions include Battery Temp after a long journey.
Battery temperature after pre heat cycle
Indeed. I have similar questions. Not being able to log with the car locked (because it sets off the alarm) is a bit of a pain for the pre-heat question, but I could certainly look at the end result.

Do these SOC margins reduce as the battery pack degrades in order to maintain the usable value or are they fixed?
No idea. It needs some other people to look at what their cars are reporting. Then we can build a picture.
 

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What does concern me is that my friends with 3 year lease vehicles just don’t care. With Tesla’s they just charge to 100% all the time and rapid charge all the time no thought about battery care. There will be a lot of suboptimal lease vehicles on the market eventually.
I think there's going to be a real issue with nerfed Teslas on the used market that can't supercharge at the high rates. There seems to be a software controlled limit to the 150+kW charging speeds which kicks in after a while. A significant number of Model 3's are hitting it.

Not something the i3 has to worry about down at 50kW I think.
 

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Discussion Starter #9
The bit that most people never see is the fall in total battery capacity over time
That's why I was careful to say "my car" has those buffers. It's coming up to 3 years old, so would be interesting to compare against a new car.
 

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What does concern me is that my friends with 3 year lease vehicles just don’t care. With Tesla’s they just charge to 100% all the time and rapid charge all the time no thought about battery care. There will be a lot of suboptimal lease vehicles on the market eventually.
I agree: aided and abetted by the manufacturers whose sole interest is getting the car to the end of its battery warranty period of 8 years. That said, with a predicted life of 250,000 miles for the i3 electric engine we may see i3s on the road for many years to come. It is only a question of time before someone offers an affordable battery retrofit.
 

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hi,
you can code off alarm function when something connected on obd. But after car is locked i can't read any data through deepobd.
I can probably read temperature readings over long journey this weekend.
 

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Discussion Starter #12
hi,
you can code off alarm function when something connected on obd. But after car is locked i can't read any data through deepobd.
I can probably read temperature readings over long journey this weekend.
Yep, I've noticed the same. The car seems to need to be in, at least, "On, but not Ready" state for things to work.

I did a bit of a longer drive on Monday, maybe 60 miles. The battery temperature was very slow to increase. It seems to be there's no active battery heating going on. Just the heat that the cells generate themselves through use. The cooling system is just that.... a cooling system. What really seems to drive up their temp is regen, or dumping energy into the battery in general.

I started the drive at about 10℃ and headed on the motorway at a cruise controlled 70MPH. Battery temps rose 1 degree, but when I hit an average 50MPH zone and knocked 20MPH off the cruise control, the regen seemed to raise part of the pack up by 1-1.5 degrees in a couple of seconds. I say part of the pack, because only the maximum temp rose immediately, and then the heat evened out over the next few minutes.

I stopped for a quick 10 minute 50kW charge adding about 10-15%. That pumped the batteries up from around 13℃ to 18℃, but I didn't need any more than that, so I didn't bother hanging around for no reason.

Nothing very surprising here.
 

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Are you using a phone to view the results?
I went to download the app onto a Sony Xperia tablet, simply because I prefer a larger screen, and Google Play Store warned me that the app was not optimised for my device. I didn't download, but instead went searching for information about the warning message.
In general the same message applies for many apps and many devices, but I could gain no clear picture about how much effect the 'non-optimisation' would have on the performance of any particular app.

Regards.
 

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Interesting,
Raises questions like how much does a 4 hour 7kw charge raise the battery temp? As this may mean if you time it right you don’t need the battery pre condition ? Or if the system is cooling only how does it heat? I notice the pre condition does suck about 6.5kw for about 15 minutes on my charger.
 

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Are you using a phone to view the results?
I went to download the app onto a Sony Xperia tablet, simply because I prefer a larger screen, and Google Play Store warned me that the app was not optimised for my device. I didn't download, but instead went searching for information about the warning message.
In general the same message applies for many apps and many devices, but I could gain no clear picture about how much effect the 'non-optimisation' would have on the performance of any particular app.

Regards.
I think that warning is about the screen size/shape, but I'm using a Nexus 9 tablet and it's fine.
 

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... It needs some other people to look at what their cars are reporting. Then we can build a picture.
Just to say that I'm following your lead down the same path.
Apart from that statement, primarily made to encourage others, this post is simply to capture my route through the obstacles I feel I have encountered just to reach the point where I can start recording data.
Ulrich, the writer of the Deep OBD app, frequently reminds people that it's for 'Expert Users', qualifying this by saying he doesn't have time to hand-hold novices. Against that, he has responded to a fair number of feedback comments at the Google Play Store.

I will start by saying I don't feel I fall into the Expert User category when it comes to computing software, but I thought I'd exercise the little grey cells and give it a go.
You will see I already raised a query about the app 'not being optimised for my device', but encouraged by the response I downloaded the app onto my Sony Xperia. I also visited, and read several times, the page referenced by Weebull in his second paragraph. This page is important.

I then installed the application and was asked if I wanted to install Yanex translate.
I wasn't quite sure whether this was to translate technical gobbledygook into simpler phrasing, or to translate German to English (or even German technical gobbledygook into simpler English), but as both the car and the software developer are German, and I neither speak nor read German, I thought I'd accept the offer.
It turns out this is a free service / program, but as is often the case nowadays, the user has to Register.

My first real test came when, as part of the registration process, I needed to offer my phone number. My entry was rejected as being in an Invalid Format. Googling the error message generated enough clues for me to realise the number had to be in International format, starting with the country code. (See, I'm not an Expert User!!).

Creating the API key, and copying it, tested my skills in using the Tablet, but I managed in the end. I prefer a Windows based Laptop or Desktop, but Deep OBD only works on the Android Operating System, so the less preferred Tablet had to be used.

Next, the OBD Bluetooth adaptor.
Following the page referenced by Weebull in his second paragraph, the pre-programmed version wasn't available, as predicted. I thus followed the suggestion to shop via AliExpress, another first for me. AliExpress seems to be a front end for multiple retailers (similar to, but definately not the same as, Amazon). I used the recommended search terms 'PIC18F25K80 ELM327 '. I could not find references to the chips mentioned (CSR BC417 or BK3231).
I also searched on eBay.co.uk but didn't find any home-grown results.
Just going by the picture, there were several retailers of this device on AliExpress, I went for the one who appeared to have sold the most. They also had a lot of complimentary feedback.

As a new user of AliExpress I was immediately granted some money off coupons (provided I registered!!). This time I remembered, and used the International format for the phone number!
So, £3.31p later, the adaptor is ordered.
Given Coronavirus, or Covid19 as it's now been termed, I have no idea when it will arrive.
I think I've done as much as I can, especially now I've capured this detail.
Programming the adaptor is a later adventure :)

Regards.
 

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Discussion Starter #18
Yeah, it's not a simple process, and thanks for putting your experience so far. Must admit, I might have been a bit blazé with the accesibility of it all. Hope you manage to get something working.

My first real test came when, as part of the registration process,
Was this for the translation service? I didn't bother with that. Didn't find it necessary.
 

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This is an update of where I am now, and a little bit of how I got here.
I didn't buy the preprogrammed OBD adaptor from Ulrich because he has clearly sold all his stock, and has yet to restock.
I bought a standard OBD adaptor from eBayUK. There are ten's if not hundreds to choose from, but the main requirements seem to be the right PIC chip, with Firmware at 1.5. On eBay UK I did not find the one pictured by Ulrich.
This is the one I chose, selecting the Bluetooth and Android options. After some advice from Weebull I decided to proceed without installing the DeepOBD upgrade.

I had already downloaded the app from Google Play onto my Sony Xperia, despite it 'not being optimised for my device'.
Plugged the adaptor into the OBD socket in the car, disconnected the charge lead so I could switch the car on, then ran the DeepOBD app on the Tablet. The app recognised no adaptor was found or paired, so took me through the process of finding and pairing, including giving me the 'slow' warning because I was using a standard adaptor.

The app then proceeded to read the units on the car, including feeding back the correct VIN.
I haven't specified which units I want to monitor, so obviously haven't collected any data.

I closed down the app and the tablet, and that's almost where I left it, except that because I found the OBD socket difficult to plug the adaptor into, I have left the adaptor in place. I have sucessfully driven the car a few feet backwards and forwards, just to prove it will drive, then locked it and left it on charge, without any alarm sounding or showing.

Next steps are:
To collect some data, just not sure when, possibly mimicking the selections by Weebull, just for comparison.
I will probably order an OBD extension lead just so the adaptor can be placed where I can see the lights. At the moment I am hoping the OBD socket is powered down either when the car is switched off, or locked, or after 5 minutes when the 12 volt accessory sockets are powered off.

The conclusion so far is that, if you restrict yourself to a standard OBD Bluetooth adaptor such as I have bought, you do not need a significant degree of computing expertise.
In other words, ignore the Yanex translation service, and ignore the DeepOBD upgrade to the Bluetooth OBD adaptor.

Regards.
 
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