How to measure your BMW i3 battery state of health using the Electrified app
2024 ж. 15 Мам.
13 372 Рет қаралды
In this video I have a quick look at how you can best measure the battery state of health in a BMW i3 using the new Electrified app. This currently only works on Android phones and of course you need a suitable bluetooth ODB2 dongle. I'm using an Konnwei donngle.
For EVs for sale, see www.gogreenautos.co.uk/for-sale
To look at the back catalogue of EV videos on this channel, see / gogreenautos
Why not follow Go Green Autos on Facebook at / gogreenautos ?
So glad I came apon this video...I was getting really strange voltage drops after a NEW software upgrade from BMW. It became quite disconcerting until I used this app and found out that in fact the actual battery voltage was NOT dropping but the indicated % certainly was!!. When I finally decided to do a test, I had already "lost" about 7 % artificially...I came back with 20% and went 96 kms at a steady 90 kph. Thats an indicated range of around 120 kms. However the voltage was 361 volts. Thats 3.76 volts per cell. Its no wonder these batteries last so long. If this battery (and I cant find any information on it but can make an educated guess) has 3500 cycle life compared to 7000 for the 96 ah battery, then at 72000 kms-5100 kms on the rex thats 66900 kms. So if averaging 90 kms on a full charge that would be (66900/90)=743 cycles. 21% of the rated cycles and thats assuming the battery was cycled all the time with 100% and down to 6%. Also, on the app its says exactly what yours says..48.5Ah capacity and then dividing this by 60ah gives 80% SOH...however...since we know that BMW limits the battery to only 88% then 60ah-12% is 53ah available.So new we know the battery has a useable KW of 18.8 . so now 53ah x 355=18.8. If you take 48.5 AH x (3.7 volts x 96 cells) x 355 you get 17.2AH. 18.8ah when new divided into 17.2 give you about 9% degredation. However if the stated 48.5ah is again limited to 48.5-12% then you get 42.6ah x 355 which would only be 15.15 KW. thats not nearly enough as I calculated that I was getting about 16.5kw (range driven divided by % used x kwh/km) which again is closer to the 17.2 ah figure. My KAPPA has been as high as 16.2 and as low as 14.9 all in the space of 1500 kms.
What are the chances that the time on your phone is nearly the same as the available capacity? 15.4 kwh and the time was 15.42
SOH is innaccurate but what about SOC max and min? How can we reset the max value? In my i3 (94Ah) i see that this value is decreasing
At a BMW service centre, their pro tablet is able to read battery maximum capacity in KWh. I’ve seen that figure for my own car but I wonder if it’s reliable coz it was pretty spectacular
I highly suspect it is just reading the same figure as that is all the BMS reports.
Is it true that frquent CCS DC charging degrades batteries faster? I assume the car's computer doesn't record charging sessions and one needs to keep a notebook (as one records petrol filling with an ICE car?)
In theory yes - but in reality no. Many repeat the same old rumours about EV batteries but in reality (and speaking generally here) DC rapid charging doesn't effect batteries. Heat does though, so if a battery is repeatedly DC rapid charged in succession and driven fast between each charge, then a battery can get hot. But in reality, a battery is rarely charged more than one or twice in a day. And of course, all EVs except Nissans have active cooling to protect the pack. I've seen ex-Taxi Leafs that have done thousands of DC rapid charges and their batteries are not any worse than other Leafs of the same age. Yes, EVs generally do record the DC charges. i3s do. However, the user can't see this information without a diagnostic scanner or a dongle and software.
@@GoGreenAutos Thanks
I think the electrified app uses the Batt. Kappa. Max figure to provide the SOH percentage which most i3 owners / enthusiasts know is a very poor guide to SOH. If you’re range of 65 miles is at 80% of the original capacity then it would suggest the range at 100% at this time of year is 80 miles which is just not possible at it would suggest an efficiency of 4.2 miles / kWh. After owning an i3 through 2 fairly mild winters I can assure you that 4.2 mi/kWh just isn’t possible. The most I got from my 60Ah i3 with the REx was around 75-80 miles (69 miles out of 85%) but that was in Eco Pro + during the summer driving at very sedate speeds.
Mel has been getting 80 miles out of this i3 in the summer and 65-70 in the winter. Due to this, I was expecting the battery SoH to be considerably higher than 80%.
@@GoGreenAutos I think this just goes to show how inaccurate the Batt. Kappa. Max figure really is.
Hello Go Green Autos. I bought the same OBD as you but it doesn't work on the Electrified app. It works on Car Sanner. I use Android on Xiaomi. Should I change something in the phone settings? After connecting, it does not show any parameters and after a while a message pops up : "Not able to communicate with the car! Switch Ignition On and try again". And so it connects all the time, does not show any parameters and after a while a message.
Sorry I can't help you with this one. I filmed this video over 3 years ago and haven't used the app since.
What do you do with one of these when the battery has degraded to a point where its range is useless? I dont see any upgrade kits out there to replace it.
No market yet for that.
Doesn't the 2015 i3 have a 22kwh battery? so 15.4 divided by 22 is 0.7. 70% capacity? isn't that bad? You should be able to claim warranty? Is my math wrong?
Yes they have a 60Ah battery which is 21.6kWh, with a usable capacity of 18.8kWh when new. The current kappa-max figure of 15.4kWh is about 80%. But battery state of health does fluctuate and goes up as well as down. When looking at this data, you're only getting a snapshot of the capacity at that time. At the time of filming this, the i3 had been sat in the unit unused for well over a month and it was also very cold (sub zero from memory), so while it was 15.4 at the time, I would expect it to rise quite a bit when the battery was warmer and being cycled. It fluctuate a lot in an i3 and isn't a reliable measure of average battery health. In reality, we've been getting the same range out of this i3 as it when it was new and I would say the battery was nearer 90% SoH (on average)
@@GoGreenAutos Thank you. In my case, if I went to a dealer and showed them my computation, will they warranty the battery? If this is not a reliable way to find out the SOC then what is?
@@johnj2803 I guess the only way would be by taking multiple recordings over time and different temperatures. Of course no one is going to do this, so the SoH is always just a snapshot at the time you are looking. I'm guessing you're worried about the condition of the battery. Unless you live in a hot climate, the battery would typically last the life of the vehicle and wouldn't drop to a level where a warranty claim would be valid.
I wish Renault had more informative apps!
canze.fisch.lu/about/ ?
@@GoGreenAutos I am an IOS user, thanks for the link!
Android auto i3s