Battery capacity issue

[errante]

Hello,

I have an issue with my 2014 BMW i3. Battery capacity shows about 40-45 miles when charged at 100%. At 70% charge it shows 27-29 miles range. To my understanding this is way under the 70% capacity to be considered excessive under warranty.

These numbers are in the summer and gets worst in winter.

I have taken it in for service to 2 different BMW dealers about 6 times and they always say they follow all tests BMW tells them to do and find the battery under normal capacity. I feel like they are pushing back to not honor the warranty and I’m not sure what else to do.


https://imgur.com/a/Zbdk1L9

https://imgur.com/a/7Lv9jCK

 

[i3Houston]

Try a different dealership.
Send results to BMW directly.
Check Battery Kappa under service menu.

I have 2015 i3, the lowest range guesso-meter has shown is ~50 miles and that was due to driving to fast/hard. So if you dont live up on hill top and dont drive too fast up there, then the battery is definitely appears to be at half of its original capacity.

 

[gt1]

Ask the dealer for the detailed test results and post them here.

 

[Anonymous]

Is the range shown in the "guess-o-meter" accurate to actual driving? - If you are fully charged, set your trip-counter, and compare it to the guess-o-meter range - a difference would point to a software issue. If actual and guess'd range are spot-on, then a hardware issue.

Since you have already tried several times through BMW Dealers, do a search for "BMW Customer Service", and contact them directly with this - certainly not normal at all, unless you are driving the car like you are running the Indy 500 - if you drive it like it's a race-car, the guess-o-meter will show that, and drop your range accordingly. You can easily knock 30% or more off of your range by "spirited" driving, just like doing so in an ICE car will reduce gas mileage significantly.

My car made a 50 mile trip from the Auto Auction lot to the Dealership, before I picked it up. When I started driving it, the guess-o-meter range increased over 20 miles - likely because the Dealership driver "drove it like he stole it" on the way back from the auction lot and that was what the guess-o-meter was calculating range from.

 

[errante]

I constantly get this low range in the guess o meter with normal driving and it matches the miles in the trip meter. I definitely think it’s a hardware issue.

I will post the dealership test results here once I get them.

Thank you for the replies!

 

[Atv]

Hi,

Any update? I noticed a similar thing on my 2016 with about 22k miles, showing about 50 miles on battery and 41 on gas, nearly a full tank of gas.

Thanks

 

[Atv]

Just checked the battery capacity in the hidden menu and looks like my batteries are holding up pretty well, 17.5kwh, 2016 with 20k miles.

 

[jadnashuanh]

You don't mention where geographically you're located and the ambient temperature. The temperature of the batteries will have a huge impact, more so on the REx verses the BEV when it's cold out. If you set a departure time while plugged in, you'll warm the batteries and should probably precondition the cabin to maximize your ultimate range. But, when it's particularly cold out, you can be spending a significant portion of your available energy heating things up versus actually moving the vehicle. Worst case would probably be a bunch of short trips where the car has an opportunity to cool to ambient each time. It will then be using lots of energy rewarming the cabin and this can be worse if you need to use the defrosters for both the front and rear. The REx relies entirely on resistance heating, so one watt of heat uses one watt of battery. The BEV's heat pump multiplies that by maybe in the order of 1W of battery transfers 3W of heat, so can be much more efficient, but only when the temperature isn't truly frigid, then it reverts to the resistance heaters. Those may get activated initially when it's really cold in both vehicles.

Last, keep in mind that the estimated range is based on about the last 18-miles of travel. IF that was a cold start and lots of heating, your mileage to empty could be quite short. That estimate could easily be wrong if the next trip was done with setting a departure time with preconditioning of the cabin and it was one continuous trip verses lots of shorter ones. All in all, that is similar to an ICE...lots of cold starts where the vehicle uses more fuel so the engine will run smooth during warmup will wreck havoc on your ultimate mileage versus a longer trip after fully warming up. At least on an ICE, the heating is a waste product so that's not an issue.

 

[CharonPDX]

Just checked the battery capacity in the hidden menu and looks like my batteries are holding up pretty well, 17.5kwh, 2016 with 20k miles.

2015 REx with ~16k miles, 17.9 kWh through the hidden menu for me.

And for those who don't know how to get to the hidden menu: https://www.youtube.com/watch?v=tw5i1Ki-RpY

Note that when it's colder out, it will read lower (because the battery's capacity is lower when it's cold.) It was 5°C when I did my reading. So if it's currently cold where you are (below ~10°C / 50°F) don't trust that the reading you take right now is "the definitive reading." Take readings every couple months, in different temperatures.

 

[JLB2]

Does anyone know if BMW has actually replaced an i3 battery under warranty because capacity degraded below 70%? If so, can you share any links to this information?

My 2014 i3 indicates a range of about 61 miles at 100%. Kappa Max indicates about 15kwh. Car is driven about 48 miles/day in N. California. I'm hoping to have the battery replaced under warranty at some point.

 

[bwilson4web]

Does anyone know if BMW has actually replaced an i3 battery under warranty because capacity degraded below 70%? If so, can you share any links to this information?

My 2014 i3 indicates a range of about 61 miles at 100%. Kappa Max indicates about 15kwh. Car is driven about 48 miles/day in N. California. I'm hoping to have the battery replaced under warranty at some point.

15/18.6 ~= 80.6%

You are going to have to abuse the battery a lot more to get to a credible, 70%.

Bob Wilson

 

[Anonymous]

My 2014 i3 indicates a range of about 61 miles at 100%. Kappa Max indicates about 15kwh. Car is driven about 48 miles/day in N. California. I'm hoping to have the battery replaced under warranty at some point.

You need to remember that number is a computer guesstimate, not an actual hard range number. When you are fully charged, set your trip-counter to zero, and use that to get a more accurate idea of your range. Be aware also, that temperature affects range. Between 60 and 70 degrees, I get my full 71 miles, which is the advertised battery range for a 2015 Rex.. Between 40 and 50 degrees, I can knock almost 10 miles off that.

 

[JLB2]

Right, but I haven't seen a 71 mile range since 2017. My range at 100% charge has indicated between 52 miles and 65 miles since last Summer. Its been at about 52 and 61 miles this winter. Degradation seems to be accelerating. I'm wondering at what point I can take it to BMW to have the battery replaced under warranty.

 

[JLB2]

Bob - The capacity dropped to 95% from 2014 to 2017 then to 80% from 2017 to 2018. I figure it'll drop to 70% by the end of 2019 or early 2020.

I'm just wondering what I have to do to get BMW to honor the warranty. They seem to be fighting it. As more and more 2014's get older, I'm sure there will be more claims. It might be helpful to everyone if we could all share experiences of making a battery warranty claim.

 

[websterize]

I'm just wondering what I have to do to get BMW to honor the warranty. …

You have to find a dealership willing to go to bat for you with BMWNA.

 

[Anonymous]

I'm wondering at what point I can take it to BMW to have the battery replaced under warranty.

The stated usable capacity for the 2014 i3 is 18.8 kWh. So the battery would need to degrade to 13.15 kWh to trigger a 70% threshold warranty claim. According to BMW, if the battery capacity does fall below 70% the car's telecenter actually notifies BMW the battery has issues. I think that's why dealers aren't keen on going to bat if someone claims to them that the battery needs replacing. If the car hasn't "phoned home", the battery isn't at 70%.

 

[Oleksiy]

That's a very convenient position indeed! BMW learned well from Nissan's mistakes - those poor guys would replace a battery as soon as the dashboard bars go below 9. But in case of BMW only dealers can say if the battery is OK or not. And it's usually OK from what I read here and other forums. You should not rely on Batt.Kapa - it doesn't mean anything, varies too much, is affected by weather and stuff. You shouldn't rely on the GOM reported range either - it depends on your driving style, ambient temperature, humidity, gradient, etc. Please trust BMW, they know better when the battery is toast :roll:

Seriously, I've read several cases of people asking dealers to check their battery condition after the range dropped to 50 miles and lower, and Batt.Kapa to 12-13. The outcomes have been the same yet - the batteries were checked and brought back to 14ish kWh or higher via some magic or parts replacement (cell supervision circuit 6 and the SME module in the recent case described in FB group post). And the batteries were OK, according to the dealers. Following

 

[jlangham]

That's a very convenient position indeed! BMW learned well from Nissan's mistakes - those poor guys would replace a battery as soon as the dashboard bars go below 9. But in case of BMW only dealers can say if the battery is OK or not. And it's usually OK from what I read here and other forums. You should not rely on Batt.Kapa - it doesn't mean anything, varies too much, is affected by weather and stuff. You shouldn't rely on the GOM reported range either - it depends on your driving style, ambient temperature, humidity, gradient, etc. Please trust BMW, they know better when the battery is toast :roll:

Seriously, I've read several cases of people asking dealers to check their battery condition after the range dropped to 50 miles and lower, and Batt.Kapa to 12-13. The outcomes have been the same yet - the batteries were checked and brought back to 14ish kWh or higher via some magic or parts replacement (cell supervision circuit 6 and the SME module in the recent case described in FB group post). And the batteries were OK, according to the dealers. Following

I just got my 12v battery replaced at the dealer and wanted them to check my main battery because my Battery Kappa is always in the 12 to 13 range - even though my range on the GOM often says 70ish. The dealer checked my main battery and told me that it was at 92%!!!

Of course I told them that they were full of sh!^ and that I believe soon my car will indicate that it will need replacement.

I think the dealers have all been told NOT to replace the batteries under warranty. No other way to see it with that much of a discrepancy in what the car is reporting.

So are we saying that the car has a Battery Kappa number that means absolutely nothing? If that's so, why is it even there? Why monitor it? Why display it?

I know some of you will just say it's used in the overall calculation and that other numbers/factors are there to determine what the "real" life of the battery is. I just find that kind of convenient to not have us know and ONLY the dealer. Of course, they will always say that "it's good!"

 

[alohart]

I just got my 12v battery replaced at the dealer and wanted them to check my main battery because my Battery Kappa is always in the 12 to 13 range - even though my range on the GOM often says 70ish. The dealer checked my main battery and told me that it was at 92%!!!

Did your dealer charge you for the Li-ion battery pack capacity test?

Batt. Kapa. max is just a calculated capacity value that varies with conditions. The only way to truly test the capacity would be to completely discharge/charge the pack and charge/discharge it under controlled conditions. BMW hasn't publicized the conditions under which the nominal usable capacity for a new battery pack was determined. It was almost certainly done at an optimum temperature and at a pretty low current, maybe lower than the pack experiences in normal driving. The capacity increases as the charge/discharge current decreases.

Apparently, BMW dealers can determine a capacity by slowly discharging and charging a battery pack (I've read over a couple of days). This capacity is almost certainly different from the Batt. Kapa. max value.

I think the dealers have all been told NOT to replace the batteries under warranty.

BMW has boasted about the modular design of the i3 battery pack which allows the replacement of a single module rather than the entire pack. I would not be surprised if BMW replaces just enough modules to increase the pack capacity to just over 70%. I don't believe that the pack warranty requires a complete pack replacement or even a replacement of modules containing new cells. Honda was using refurbished battery packs (i.e., packs whose modules contained used cells) as warranty replacement packs for our former Honda Insight.

So are we saying that the car has a Battery Kappa number that means absolutely nothing? If that's so, why is it even there? Why monitor it? Why display it?

Who knows? This is a hidden, undocumented menu not intended for i3 drivers to monitor.

I know some of you will just say it's used in the overall calculation and that other numbers/factors are there to determine what the "real" life of the battery is. I just find that kind of convenient to not have us know and ONLY the dealer. Of course, they will always say that "it's good!"

It is true that there is no instantaneous way to measure a capacity of any battery pack (many different capacities exist depending on conditions). So it would be difficult to provide an i3 driver with a definitive pack capacity.

 

[flyboy320]

If you have ISTA+ you can re-calibrate or re-initialize the HV battery. In the end the battery capacity does not change, it just changes or re-calibrates the GOM range and battery kappa values. Over time these values will not accurately reflect the actual battery capacity.