symonray
Posts: 74
Joined: Thu Mar 07, 2019 8:52 am

Re: ISTA Install Help

Speaking from personal experience of performing the battery reinitialization on my i3 Rex about 10 months ago, I agree with Alohart that the process most likely frees up some of the buffer capacity that the BMS had removed from the usable battery capacity. Based on the reports of others and my own personal experience, the usable capacity initially goes back to the original "as new" usable capacity amount specs (approximately 18.8kwh of the 22kwh i3 battery) immediately after the reinitialization process is completed but then slowly shrinks over time until the battery capacity is back to where it was just prior to performing the battery reinitialization. That is why many of the owners who have performed the battery reinitialization end up doing it again every 12 months or so. That reality makes me think the reinitialization has more to do with adjusting the battery buffers than addressing actual battery degradation.
Timothy Simonds
2017 BMW i3 Rex
121gwats
Posts: 11
Joined: Wed Oct 09, 2019 3:02 am

Re: ISTA Install Help

symonray wrote: Sun Feb 02, 2020 9:24 pm Speaking from personal experience of performing the battery reinitialization on my i3 Rex about 10 months ago, I agree with Alohart that the process most likely frees up some of the buffer capacity that the BMS had removed from the usable battery capacity. Based on the reports of others and my own personal experience, the usable capacity initially goes back to the original "as new" usable capacity amount specs (approximately 18.8kwh of the 22kwh i3 battery) immediately after the reinitialization process is completed but then slowly shrinks over time until the battery capacity is back to where it was just prior to performing the battery reinitialization. That is why many of the owners who have performed the battery reinitialization end up doing it again every 12 months or so. That reality makes me think the reinitialization has more to do with adjusting the battery buffers than addressing actual battery degradation.

From your experience and other's, do many owners get stranded from the bottom end range being overestimated? It makes sense that the buffer is being opened up, but I wonder if some is opened up on the top end as well.

Before performing battery reset, it was charged to 100%. I left it plugged in to the charger the whole process. After ISTA battery reset, it gulped another .6 kwh. Thats not a lot, but it is for already being 100%. My charger never tops off if you unplug and replug, so this is very unusual.
johnnyz383
Posts: 10
Joined: Sat Jul 02, 2022 11:25 am

Re: ISTA Install Help

Hey there...ok..hopefully someone reads this post. I just bought an i3 and after BMW did the latest update, seems the car was losing battery capacity just sitting..and when turning it on and off 4 times, each time the capacity went down.5 of a percent. I have lots of experience in making battery packs so know something of how these work, so when I downloaded electrified app and used it, I had access the the actual battery voltages, including the highest and lowest cells in the pack.I monitored this as I was driving and closely coorelated the percentage the BMW was giving vs the voltage. What I found out was fairly startling...NOTHING wrong with the pack, in fact when the BMW reported 20% the battery voltage was only 360 volts or 3.73 volts per cell at 96 kms going 90 KPH steady. I also saw that DESPITE the battery voltage not moving at all, I lost 5 percent throughout a period of about 4 hours simply turning the car on, moving it 2 feet and turning it off a couple of times. !!! So, I am going to see about resetting the BMS as it appears the BMW is reducing artificially the pack capacity in line with time regardless of how the pack is doing in real life. This is just absurd.Also, when fully charged the voltage per cell was 4.1, so only charging a prismatic cell to 4.1 and only discharging to 3.75 volts would at least increase the usuable cycle life by 30% before experiencing the same degradation as charging to 4.25 volts and discharging down to 3.4 volts.The 96 ah pack is 7000 cycle capable and so in all probability the 60ah has at least a 2500 life cycle. SInce my car has 72000 kms and the rex has 5100 kms of run time, you can extrapolate 66900/90 (assuming 90 kms per charge) is 743 cycles..so that would mean you have only cycled 30% of the available cycles, but since BMW denies you at least 15%, and if you add 30% to 2500 you get 3200 cycles. ..and based on my observations and doing some math this battery has very little degredation..but not according to KAPPA and the BMS.
MagicCarpet
Posts: 62
Joined: Fri Mar 08, 2019 1:17 pm

Re: ISTA Install Help

Interesting, I'm about to put my i3 on a top up AC charge session as I mostly DC rapid charge which stops at 95% and I should occasionally do the full 100% to allow BMS balance to occur. Havent done this for a while as normally dont do long trips - just recharging from low-ish to near full in one session rather than continually putting small charges in


Besides, for now DC rapid charge is free, may as well use it and Japan i3 have the larger Chademo connector at the rear and the AC socket hidden in the frunk, making home charging slightly less convenient.


Rex runs the mtce cycle roughly every 60 days, please advise how you know your Rex has run 5100 km?
I dont know where to look for this data. I assume my Rex has done 6 mtce cycles per year plus the few times I used it or around 2 hours per year.

On the ISTA subject, I'm having another attempt at downloading this, thanks Alohart for the new link - see the posts in regional threads
johnnyz383
Posts: 10
Joined: Sat Jul 02, 2022 11:25 am

Re: ISTA Install Help

Hey there...When I got the dealer to to a diagnosis, I wanted to know how much time the rex has been run (the computer keeps a log time of this), and thats what they told me, however they wouldnt tell me anything else as they said they dont share error codes or anything like that with customers. Such bullshit. Really bad experience with this dealership so far. I run the rex when I need it to extend the battery charge ( I have coded the car to allow me to turn it on when the battery is below 75%). So many rumors and not enough facts. The little rex can be run as often as you like with no ill effects. The generator is actually an electric motor attached to the driveshaft of the gas motor and when activated starts the engine and then polarity is reversed and the motor acts as a generator. This will never wear out, and at only 5100 kms the motor has PLENTY of life left. Also, running the rex will prolong the life of the main battery pack.
MagicCarpet
Posts: 62
Joined: Fri Mar 08, 2019 1:17 pm

Re: ISTA Install Help

Thanks for the info about Rex runtime, I'm guessing the dealer used ISTA to read it out - I havent quite got there yet.

Finally downloaded Aloharts 4.10 link to ISTA+
The diagnostic part opens and runs however I'm not certain of this ISTA+ being inluding the ISTA-P files and I dont see any ability to select programming.
The downloads I attempted 2 years ago were in one smaller file about 15 GB and on larger of about 50GB - the one I was never able to download. Those old links no longer work so cannot trace back to see what they were.

After carefully re-reading the instructions there is a section which states ISTA+ will work with i3 and Mini etc. without requiring ICOM interface, just Enet adaptor but in the same article a heading states that to do programming on i3 / mini Enet wont work and ICOM is required.

So a lot of confusion whether ISTA+ is truly both parts (ISTA-D and ISTA-P) or the GUI is ISTA+ but only does programming if all the -P files are present in the downloads.

I cannot help much at the moment because I cannot see what ISTA-P can do and even if I could, I may need the ICOM interface to actually use it.
johnnyz383
Posts: 10
Joined: Sat Jul 02, 2022 11:25 am

Re: ISTA Install Help

The other thing I noticed and confirmed was when using the electrified app, the BMS is artificially deflating the percentage without any doubt, as I can see now the voltages and state of balance (and in my case its within a 10th of a volt from highest to lowest), and when charging to less than 100%, lets say 95%, and hardly doing anything, the percentage will drop on the car during the course of the day WITHOUT the battery voltage dropping at all. In fact there is no direct correlation between the percentage reported by the car and the ACTUAL battery voltage untill about 50% then it becomes more linear.

I suspect that by resetting the BMS you would get what the battery's real available energy is, but I do not know how to do this, and if I did if it would be safe to do so.

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