Phoenix 2014 i3 in shop for battery health check.

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jpascale

Member
Joined
Feb 8, 2017
Messages
11
Hello all,
I have been reading a lot here and thought I should let you know our current situation with our I3. We purchased it used about a year and half ago, BEV model only. It was purchased so the lovely wife could get in the commuter lane and beat some of the grueling traffic here in Phoenix. It had 12,000 miles on it and currently around 30,000 miles. I don't have any hard numbers but she would get around 80 to 70 miles range showing charging to full overnight with the provided slow charger. Her drive is mostly freeway and she would try to limit it to 65 mph or so depending on who was behind her pushing her to go faster. Her commute is 22.4 miles each way. Range as been dropping faster that expected. Lately she has been starting out with 50 to 57 miles estimated range. It is bloody hot here right now so I know that is a contributing factor. My wife is afraid to us the AC now as you would any other car and is started to suffer from range anxiety big time. This totally defeats the purpose of reducing the stress of her daily commute.
So I call out local Chandler AZ dealer and advised how much we love the car but its range seems to be diminishing rapidly. So they agreed to do a battery health check. They did it over the last few days and sent the results to corporate to review. The dealer said they would be pushing for a battery replacement. We are currently waiting for a call back.

Wonder has anyone else had their battery replace under warranty yet. If so do they give you an entirely new fresh battery or just replace enough of the cells to bring it up to some arbitrary range they feel is age appropriate?

As much as we love this vehicle we do not thing we will be getting another EV due to the extreme summer heat in Phoenix.
 
BMW touted the modular design of the i3's battery pack which would allow only "bad" modules to be replaced rather than the entire battery pack. However, if heat has caused rapid battery cell degradation which seems likely in your case, there might be no modules significantly more degraded than the others. In this situation, I would hope that BMW would replace the entire battery pack.

Because the i3's battery management system does not control the battery pack's temperature when an i3 is parked and not actively charging or when battery pack preconditioning is not active, i3's in hot climates could have their battery cells baked unless their drivers are conscientious and able to park in shady areas, not over hot asphalt, etc. The battery cell degradation rate is much faster at high temperatures and charge levels, so those who always charge to full and leave their cars fully charged for an extended period in hot conditions risk rapid battery cell degradation and the resulting range loss.

It seems that your dealer is on your side which isn't always true. Please report what happens.

Good luck with your warranty claim!
 
@alohart Did you read somewhere in BMW's documentation that the i3 does not actively cool its batteries when plugged in but not charging? This is contrary to my observations, but maybe I am mistaken. I have certainly heard the compressor running during the middle of hot days here in Austin. It is possible that it was still charging, but since my commute is only 10 miles, it seems like it should be charged by the afternoon.

Has anyone heard their car's compressor running during hot days while plugged in but not charging?

My i3 has about 20k miles on it and I got it used with about 3k on it. I have noticed little degradation in my range thus far, though Austin is not as hot as Phoenix and I park under a carport at my house.

You can choose to run the ac in the cabin or not, but some range will be lost due to the energy needed to cool the batteries as you drive on hot days. If the battery starts out quite hot, maybe the energy needed to cool is a significant factor in the reduced range. Have you used the hidden menu to check the battery temperature? At 4 pm on a recent hot day mine was sitting at 33 C.
 
When you set a departure time, I know it will warm the batteries, but I'm not sure if it will cool them except during charging. But, I'd be surprised if it didn't. Someone know for sure? You can condition the cabin without setting a departure time, but you can't delay that except when also doing it by setting a departure time.
 
Hi i know i am new here, but after reading your post i have to ask you this one overlooked question, are you still charging your battery everyday with the included level 1 charger? It seems like everything i have read so far about charging is that over time those level 1 chargers are not meant to to do as good of a job as a level 2, I have also read that the level 1 won't allow you to precondition your car which is super nice here in Phoenix to jump into a already cool car and that preconditioning will not suck precious miles as your car is already at temp. I too have bought our car for our wife. and Even though se does not use the rex very much she bombs along at 65-70 with no issues and her daily commute takes her roughly 70-80 miles. I personally think its your charger situation. not the batteries. you are not precooking your car = less miles, and your using a level 1 = improper battery charge levels. (Just my observation) if you haven't upgraded to a level 2, Why not? I did the day we got our car. Makes the most sense to us.
 
The USA level 1 EVSE is a 110vac/12A maximum device that can produce less than what the car wants to use when setting a departure time with cabin preconditioning. It may be more of a load in the cold than cooling, though. WHen it's cold out (not your problem most of the time!), I've seen mine drawing over 20A at 240vac, or way over twice what the OUC device can provide. WHen that happens, it still works, but will tend to draw down the battery some as well. The battery heater is a 1Kw device, nearly all of what they OUC can provide. I haven't recently checked how much it uses when hot out, but when the a/c is cranked, it still probably puts a good load on the OUC. Power=volts*amps so 110v*12A = 1320W while 240v*20A=4800W, a sizable difference. Also, in the car, the conversion from 110v verses 240vac to the DCV needed to charge the batteries is less efficient by around 5-8%, so for every watt going in, you get less into the batteries. The actual use by the EVSE in either case is likely very similar, and much smaller (on mine, around 3-4W).
 
arodi3 said:
Did you read somewhere in BMW's documentation that the i3 does not actively cool its batteries when plugged in but not charging? This is contrary to my observations, but maybe I am mistaken. I have certainly heard the compressor running during the middle of hot days here in Austin. It is possible that it was still charging, but since my commute is only 10 miles, it seems like it should be charged by the afternoon.
I have not read that battery pack cooling is not active when an EVSE is plugged in but charging isn't active. However, if battery cooling or heating (a.k.a., preconditioning) could occur automatically anytime an EVSE is plugged in, there would be no need for the battery preconditioning function that is keyed to a set departure time.

It's possible that battery cell balancing might have dropped your battery pack's charge level enough to cause charging to start up again hours after it had stopped. If your battery pack was hot enough, the A/C compressor would start to cool the pack while charging was active.

Our i3 is in a very moderate climate where battery preconditioning of either kind isn't necessary, so I don't have any personal experience with battery preconditioning. Maybe it could occur automatically under certain conditions.
 
So update from our dealer BMW Corp sees no issues with battery at this time. We have not been to the dealer to pick up as they were apparently doing a software update and it crashed (Windows 98 anyone?) so they need to start the process over on Monday. So I do not have any other info at this time. I did ask for a read out on the state of Health of the battery. We may be looking to unload this car soon as it is to stressful now for wife's daily commute.

We have only use the provided 110 supplied charger and we do here the active cooling taking place in the garage at night. We did think about upgrading to the level 2 charger but with using the level 1 we had enough time that is was fully charged and ready to go in the morning. Those not familiar with Phoenix area weather it never really cools down at night and the garages stay hot all night long. It is really something to walk out of your house at 3 AM and it can still be over 100 degrees out. My thinking on the level 1 verse level 2 charges was better to charge as slowly as possible producing less heat for an already hot battery. I could be wrong.

Hopefully we can pick the car up on Monday and I will have more to report back.
 
jpascale said:
We have only use the provided 110 supplied charger and we do here the active cooling taking place in the garage at night.
That's a really tough situation because the heat from the battery pack is being exhausted into the garage causing the temperature of the air in the garage to rise. This same air is used by the i3's A/C heat exchanger to transfer the battery pack's heat which is less efficient as the cooling air temperature rises.

Does the battery pack cooling require more power than the Level 1 EVSE can provide? If so, the battery pack's charge level would slowly decrease because the battery pack would have to add to the power provided by the EVSE.
 
Cooling does occur if needed while charging, but, as far as I know, once fully charged, it stops unless still too hot until you request a departure time. I've not had it, but I've heard people say that after a hard run, then stopping, it will continue to cool for awhile without being on an EVSE, but I can't confirm.
 
I have not read that battery pack cooling is not active when an EVSE is plugged in but charging isn't active. However, if battery cooling or heating (a.k.a., preconditioning) could occur automatically anytime an EVSE is plugged in, there would be no need for the battery preconditioning function that is keyed to a set departure time.

It seems to me that the designers would want to strike a balance between minimizing the battery degradation while not using excessive amounts of energy. They may have chosen to do that by having the cooling system come on when the battery temperature rises above some amount and is plugged in regardless of any pending departures while also allowing a user to cool beyond that amount in the event that a departure is pending.

The user-specified preconditioning may be aimed more at maximizing range than preventing battery degradation; the more I think about it, the more I see maximizing range and reducing battery degradation as separate issues that both involve choices about when and how much to cool the batteries.

This is speculation, but it is based on what I have seen my i3 do; if anyone comes across some documentation about the i3's "cooling policy", or is otherwise in-the-know, please post. As someone that lives in a hot environment and owns rather than leases an i3, this is of interest to me and probably many others.
 
My last post on this subject, I am pretty sure you need to get a level 2 charger and that will make all the difference. The battery pack has its own cooling system (one reason we chose the i3 over the Leaf) and when we park our cars here in Phoenix I am sure the cooling is either taking place or will kick in soon. I think your wrong believing that a level 1 charger is better for your batteries. Get a level 2, precondition your car before you leave work, and enjoy your BMW! You can get a level 2 JuiceBox for under $500.00
 
XERT said:
The battery pack has its own cooling system (one reason we chose the i3 over the Leaf) and when we park our cars here in Phoenix I am sure the cooling is either taking place or will kick in soon.
This reminds me of reports from i3 owners in hot climates of reduced propulsion power when beginning to drive after being parked. This is indicated by grayed out bars on the power side of the power meter. This occurs because the battery pack's temperature is too high to allow full output power which could make the battery cells even hotter potentially damaging them. If battery pack cooling were automatic when parked, this problem would not occur, so these reports are good evidence against automatic battery pack cooling when parked.

XERT said:
I think your wrong believing that a level 1 charger is better for your batteries.
I agree. Level 1 charging is also less efficient thus wasting some electricity and costing more.

The battery pack cooling system uses significant power that would otherwise charge the battery pack, so charging speed and efficiency decrease when cooling is on. I have been able to prevent battery cooling activating by reducing the maximum charging current of our JuiceBox which reduces the heat produced during charging.
 
XERT said:
My last post on this subject, I am pretty sure you need to get a level 2 charger and that will make all the difference. The battery pack has its own cooling system (one reason we chose the i3 over the Leaf) and when we park our cars here in Phoenix I am sure the cooling is either taking place or will kick in soon. I think your wrong believing that a level 1 charger is better for your batteries. Get a level 2, precondition your car before you leave work, and enjoy your BMW! You can get a level 2 JuiceBox for under $500.00

I hear our cooling system kick in when we plug in to charge with our level 1 charger so not sure how level 2 charger would help?
No real need to precondition in the AM as garage keeps the car ok for morning run with ac kept at about 76.
 
Update on car pick up from dealer last week. BMW corp response was the residual capacity of the high voltage battery is still sufficient. They did a software update of some sort and range now shows around 70 when fully charged.
I did a test run today to my wife's work and back home 45 miles round trip. I drove like you would drive any gas car at 75 to 80 miles per hour on the race track freeways we have here with air conditioner set at 74. Started out with 70 miles range showing and came home with about 9 miles left. This was to show the wife that should should be OK even if she drove it like a regular car...we will see....she may want to trade it in soon.
 
There was one software update that made the battery capacity and therefore range more accurate. NOte, though, that reprogramming the car resets your history, so it has to relearn your techniques, and the results may change over the next few days once it relearns things.
 
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