Battery Replacement Under Warranty

[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.

Some posts in this forum state that they've dealers have refused to replace the battery even when capacity degraded below 13kwh which is about 70% of original. Any information about BMW honoring the warranty would be appreciated.

 

[rtanov]

That Kappa Max seems low. Our 2014 REx (28k miles since Nov '14) is showing around 17 kWh (16.6 - 17.5) in the last month and temperature here have been low. Range hovers around the 50 miles due to the cold, and my wife's commute is also 48 miles one way - she can consistently charge at work. I have not heard of a battery being replaced under warranty but have seen some complaints for low Kappa Max readings. Would be also interested to hear if someone knows of a replaced battery.

 

[i3lady]

This makes me mad. We have a 2015 i3. We were told that our battery capacity would be around 100 with a slight decrease in milage over the years. Its almost 4 years old now, and 4 mos. ago, my battery started charging only up to 50 mph - who the hell in CA can drive a car with 50 miles capacity?!

I have taken it to the dealer 2x and all they do is run it thru their computer diagnostics and as long as the readouts are fine, they say the battery doesn’t need replacing.

Not only does the battery not charge to a meaningful capacity, it goes down very fast.

Does anyone know who I can take this issue to besides the dealer? What are the exact numbers for the warranty? (Meaning what is 70% capacity charging capacity in order to trigger the warranty?)

Thanks!

 

[alohart]

This makes me mad. We have a 2015 i3. We were told that our battery capacity would be around 100 with a slight decrease in milage over the years. Its almost 4 years old now, and 4 mos. ago, my battery started charging only up to 50 mph - who the hell in CA can drive a car with 50 miles capacity?!

If this is the estimated range, it can be quite inaccurate and affected by driving conditions during the previous 18 miles which might not be the same as the current conditions.

Not only does the battery not charge to a meaningful capacity, it goes down very fast.

If this is a change from previous behavior not due to colder weather, the capacity of your battery pack might be low.

You could estimate the usable capacity of your battery pack by driving a significant distance and noting the measured efficiency during that drive that iDrive can display in miles/kWh. Note the charge levels at the start and end of this drive. For example, if the charge level at the start was 90% and at the end was 40%, the charge level dropped 50%. If you drove 32 miles at an efficiency of 4 miles/kWh, your drive consumed 32 miles / 4 miles/kWh = 8 kWh of energy. The total usable battery pack capacity would be 8 kWh / 50% = 16 kWh. The nominal usable capacity of your battery pack when new was 18.8 kWh which is apparently the capacity that BMW uses to determine the capacity degradation percentage. The current percentage of the nominal usable capacity would be 16 kWh / 18.8 kWh = 85%.

Note that this is an estimate because the charge level percentages are calculated values that aren't perfectly accurate. BMW dealers have a more accurate procedure to measure the battery pack capacity that involves discharging the battery pack to a low charge level and then measuring the energy needed to fully charge the battery pack.

Does anyone know who I can take this issue to besides the dealer? What are the exact numbers for the warranty? (Meaning what is 70% capacity charging capacity in order to trigger the warranty?)

According to the "Lithium-Ion High Voltage Battery Capacity Coverage" section of the i3's Service and Warranty Manual:
"If an authorized BMW center’s capacity check concludes that the net battery capacity is less than 70 percent of its original nominal value when it was new, this level of capacity loss is considered excessive."

So you'd need to take your i3 to an authorized BMW center which, in the U.S., is a BMW dealer certified to repair i3's.

 

[jadnashuanh]

Even in warm weather, if you're using your i3 on the freeways at 75-80mph or so, especially if you're climbing grades, your range will be down. The fairly common stop and go on the freeways when you get up to speed and then stop doesn't help, either. Regen helps, but it's never as efficient as what was used to get to speed.

FWIW, prior to the larger batteries that started to show up in 2017, the EPA range was never 100-miles unless, maybe if you babied it in EcoPro+ mode - it was in the low 80's..

 

[Anonymous]

Someone on the i3 Facebook group posted similar battery issues. Found his due to “charge and go” charging at work, not allowing the car enough time on charge to do battery cell balancing. Said after switching to leaving car plugged in overnight at home for charging, range came back after few weeks.

 

[jadnashuanh]

Unlike most battery powered devices like say a cellphone or laptop, a smart device like the i3 literally disconnects the power once it determines maximum charge and conditioning has been achieved. IOW, especially since BMW doesn't use the full theoretical capacity of the battery, it doesn't significantly degrade its life if you just let it do its thing by being plugged in. Lesser devices often can and do show degradation when left plugged in for extended time.

FWIW, after the initial charge, at least on mine, it's not all that uncommon for it to turn the EVSE back on for awhile after a delay, probably to rebalance the cells. According to the i3 book, the same amount of 'wear' on the battery occurs from 10 recharges from 90-100% as one recharge from 0-100%. I like having the full charge pretty much whenever I decide to go out and do something. After 4+ years, season-to-season for adjustments, it has essentially the same range.

 

[alohart]

Someone on the i3 Facebook group posted similar battery issues. Found his due to “charge and go” charging at work, not allowing the car enough time on charge to do battery cell balancing. Said after switching to leaving car plugged in overnight at home for charging, range came back after few weeks.

It's not necessary to have an EVSE plugged into an i3 for cell balancing to occur. Cell balancing occurs automatically whenever the battery pack charge level is "high enough". A BMW engineer apparently told British i3 owners that 85% is high enough, but I've never found any cell balancing documentation to confirm that.

If the cells' charge levels are significantly different, the charge level of the battery pack could drop enough during cell balancing for charging to commence again if an EVSE is plugged in. The cell balancing speed increases with charge level, so leaving an EVSE plugged in might make cell balancing complete a bit more rapidly, but I doubt that this would be noticeable.

So it's more likely that the situation described on Facebook was due to the i3's battery pack not remaining at a high enough charge level long enough for cell balancing to finish because the driver departed work shortly after charging. When charging occurred overnight at home, the battery pack remained at a high enough charge level for long enough for cell balancing to finish.

 

[rockphone]

Google " bmw i3 BC battery check "
You must check the actual amount of battery/energy storage capability for warranty: 18.8 is the starting point, when its in the 13 range before 8 years or 100,000 miles you can demand a free battery. Mileage is NOT warranty related. Hope that helps.
example whatch this: https://www.youtube.com/watch?v=ELT5b2YWL58

 

[alohart]

You must check the actual amount of battery/energy storage capability for warranty: 18.8 is the starting point, when its in the 13 range before 8 years or 100,000 miles you can demand a free battery.

The Batt. Kapa. max calculated value displayed in the hidden service menu can't be used to determine whether the usable battery pack capacity has dropped below 70% of the nominal new 60 Ah battery pack capacity of 18.8 kWh. The few low Batt. Kapa. max cases that I've read about resulted in a BMW dealer doing something that increased the usable battery pack capacity above 70% of the nominal new capacity without replacing any battery pack modules. Maybe the dealer balanced the battery cells' charge levels, recalibrated the usable battery capacity calculation and/or displayed charge level, or reduced the sizes of the low and/or high charge level buffers any of which would increase the usable capacity.

However, if the battery pack capacity has actually decreased to less than 70% of the nominal new capacity, the warranty does not specify that the battery pack would be replaced. Because the pack contains 8 replaceable modules, restoring the usable capacity to above 70% of the nominal new capacity might be accomplished by replacing one or more modules. It's too early to know for certain.

 

[gerryhsu38]

I have 2014 BMW i3 REX 54k on the clock, currently kapa show 13.7 max, almost decrease 0.1 every week. i estimate withing 3 month should trigger warranty, any one can share battery warranty experience?

 

[i3Houston]

Watching this thread.

2015 i3 Rex Range is ~45 miles, 90% freeway ~65MPH, AC set to 70F, Comfort Mode.

I think last year, I used to get ~50 miles range.

 

[Anonymous]

An odd factoid. On another board several i3 owners experiencing noticeable range degradation said that after replacing their (aging) 12v battery and registering the new one, their range went back to near normal. One of the owners this happened to mentioned that when their Dealer was apprised, was told was some sort of GOM/ECU software glitch.

 

[i3Houston]

An odd factoid. On another board several i3 owners experiencing noticeable range degradation said that after replacing their (aging) 12v battery and registering the new one, their range went back to near normal. One of the owners this happened to mentioned that when their Dealer was apprised, was told was some sort of GOM/ECU software glitch.

Good to know that! I had 12v battery was replaced recently so one less thing in the equation for me!

 

[XERT]

YES, YES, and YES they will...As We Just found out today that our local BMW dealership is going to replace all eight battery cells. Not seen much chatter about them stepping up to the plate and replacing them under warranty, in other prior posts and my research I have found that BMW has done everything to try and avoid this expense. To our surprise, we became one of the lucky few. It was unexpected as we had our air conditioning compressor fail last week (our course we are out of our factory warranty) the new compressor cost us almost $3,000 to replace. Unfortunately, we had to bring it back to the dealership the next day because the A/C had cut out again. They performed a battery capacity procedure (takes 24 hours) and when the result came back, they texted me this, "Based on the results of the capacity test I went forward with a request to the BMW electric mobility team for a High Voltage Battery overhaul They have agreed with my assessment and approved my recommendations. All 8 cell modules will be replaced inside the HV battery pack under the battery warranty coverage. I am currently in the process of getting all the needed parts for the repair ordered. Once I know the availability I can provide a better time frame of when the repair may be completed." There is hope for all 2014 owners. And yes BMW does indeed honor that 8/100,000 battery replacement program.

 

[i3Houston]

Wow this is the first I am hearing! Sorry to hear about the compressor.

 

[lopezjm2001]

I read about BMW i3 AC compressor failures on the 2014/15 models on almost a daily basis sadly on the Facebook page - BMW i3 Worldwide Group. If caught early the replacement is cheap, if not the metal bits from the AC comoressor can go through the whole system which then becomes even more expensive. It can also affect the batteries life as the AC compressor is also used to cool down the HV battery. You are one of the lucky ones.

 

[i3Houston]

I feel incredibly lucky for sure... Having ac compressor, 12v battery and media control console replaced under warranty in literally last few months of outstanding warranty.

 

[Rmns116]

Newbie here. Purchased a 2014 i3 Rex a couple of months ago. Been reading all the battery kappa stuff and had noticed that my range decreased when sitting at the office. I checked my Kappa yesterday and today. Came in at 13.3 and 13.4. I live in Houston and until the last few days it’s been 100+ with high humidity (great for the skin). I’m not super concerned about getting this checked out but at the same time I wonder if this is normal or if I will maybe qualify for a replacement. Any advise?

 

[opossum]

Well, it looks like we are really close to a battery warranty claim. I'm curious if anyone has any thoughts on our situation.

2014 model. I believe it was originally purchased in February 2015, based on when our various warranties expire.
We purchased the car as a certified pre-owned vehicle in October 2017 (at 37,000 miles).
Now, in December 2019, it has 60,000 miles.

According to BMW's own test this month, we are at 72% of the original capacity, which puts us just 2% away from the warranty threshold. Our real world range and kappa values agree with this.

We live in Phoenix and already went through this heat accelerated battery degradation fiasco with the first model year Nissan Leaf (2011). With the i3's active thermal management, we expected much better results this time around! I know a few local Fiat owners who have seen far less battery degradation with comparable miles and these same battery cells. I fired off an email to our service manager to open a discussion about whether we should be scheduling a follow-up battery test for the spring of 2020 or whether there are any other things to consider, but have yet to hear back. We lost 28% of our capacity in roughly 60% of the warranty period, so clearly we'll be well below the warranty threshold well before the end of the warranty period.

I don't see a way to upload my Excel plot of our recent max kappa values, but here's the data. If you plot this, you'll see the value is dropping quite quickly! The other odd thing you'll see is that after we got the car back (they did a software update and battery test), the max kappa value mysteriously increased from 13.7 to 14.9 and we are seeing a slight increase in range. Did they just 'give' us a sliver of the reserved battery capacity to delay a warranty claim? It has been over a week since we got the car back from the dealer and we still see roughly 10 miles more usable range, though it is still far short of what it once was.

Date Capacity Kappa Miles
6/14/19 77% 14.5 55147
7/30/19 76% 14.3 55937
8/29/19 75% 14.1 56761
9/18/19 75% 14.1 57256
9/29/19 74% 14.0 57609
10/28/19 73% 13.8 58570
11/27/19 73% 13.7 59653
12/5/19 79% 14.9 59819