Battery pack longevity

[SteffanG]

The contactors themselves are very reliable as they are not switched under load (that is the main failure of contactors). That said, there have been a few Tesla cars that have been bricked for this exact reason , contactor fails and the car doesn't work anymore.

It is more of a safety thing to protect people, especially in an accident (my 2011 Audi Q5 has a battery pyro disconnect that will go off and disconnect all the large 12V loads when the airbags go off).

Interesting that the machE will charge up the 12V battery while being off. I would think that could be dangerous if it came on with no notice while someone was working on the car (people do stupid things...)

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[Kiggulak]

The contactors themselves are very reliable as they are not switched under load (that is the main failure of contactors). That said, there have been a few Tesla cars that have been bricked for this exact reason , contactor fails and the car doesn't work anymore.

It is more of a safety thing to protect people, especially in an accident (my 2011 Audi Q5 has a battery pyro disconnect that will go off and disconnect all the large 12V loads when the airbags go off).

Interesting that the machE will charge up the 12V battery while being off. I would think that could be dangerous if it came on with no notice while someone was working on the car (people do stupid things...)

Oddly enough when I got into my Focus Electric this morning. I heard the repeated clicks of the high voltage contactor failing to engage. Usually a single louder clunk instead of the clicks. Dashboard would not illuminate and the headlights flickered. When I turned off the headlights the contactor closed and the dash illuminated and normal chimes that the car was ready to drive.

I reduced the load on the 12V and it was able to pull the contactor in.

A minute or two later Ford Sync emailed me to plug my car in and charge the 12V battery. This is the first sign that my 12V battery is failing. Last time I had a few weeks after the first "false start" before the 12V battery when down hard.

I drove to work parked without charging and at the end of the day my FFE started normally and I drove home to level 2 charging.

Moral of the story Ford has been charging the 12V battery with the traction battery since at least 2013.

 

[MickeyAO]

If you watch my video from the Ford Lightning Tour Daytona I ask Max about how Ford manages the battery pack in the Lightning compared to the Focus Electric to protect the battery by never taking the pack to 100% SOC.

Also in this video (7:20+) we discuss the liquid cooling system in the Lightning and how the owner has to activate the remote start to engage liquid cooling when not plugged in or driving. True for hot or cold weather.

This is true for Ford Focus Electric and should be true for the Mach-E and the Lightning.

You can drop the battery with 8 bolts and replace individual cells in the Lighting battery pack ... so no need to replace the entire pack.

Not sure if there is data on battery pack performance with mixed new and old cells but @MickeyAO might know or can point us in the right direction.

I highly doubt they will be able to replace individual cells in a module. While I have not seen anything on this pack, it is standard practice to lazor weld the bus bars to the strings (the group of cells in parallel). I know from personal experience that these welds are VERY hard to break and I will end up destroying parts of the cell tab. Also, I don't want to mix old and new cells in the same module or string because they will not behave the same! The OCV curve (open circuit voltage) changes with cell degradation.

It will be much cheaper/faster to simply replace the module and send the old one off for recycling.

 

[MickeyAO]

The 12VDC system is there as all of the components and computers for cars run off of 12VDC, it wouldn't make sense to redesign everything for 400VDC or 800VDC.
The other concern with anything but 12VDC (maybe 24VDC but again that requires a redesign) is safety. Do you really want to work on the car when there is high voltage wires everywhere? Also, what happens if you are in an accident? That is a lot of exposed high voltage wiring going everywhere. For safety reasons there will likely always be a low voltage battery to run all the vehicle systems.

Another reason is cost. 400/800V insulation is a lot heavier and expensive than one for 12V.

Also, the reason the car becomes undriveable when the 12VDC battery dies is there is a main contactor on the high voltage battery for safety. When the car is off, the contactor is open so all high voltage wires have no voltage present. The contactor is turned on and off from that 12V battery. Now if only the manufactures would put in a system to recognize that the 12V battery is getting low, give a warning that the HV battery is going to turn on, and charge up the 12V battery to make sure it doesn't die (or at least put in a battery management system like Audi uses - when the battery starts getting low it starts switching off systems to prevent it from dying)

As I give tours and people see under the hoods of the vehicles we are working on, they ALWAYS comment on the 12 V lead-acid (might be a Li-ion replacement) and wonder why it is there. It is to run all the ancillary services., including the main contactors for the traction battery.

You will also find a DC/DC converter since EVERYTHING needs a backup on a vehicle with a certain level of automation. I found this out the hard way when working on the coolant system of a vehicle that I 'safed' (removed service disconnect on traction battery, disconnecting the Fireman's loop and current lines to 12 V) and ended up with coolant all over my lab floor because of the DC/DC converter.

 

[EaglesPDX]

The article you posted states engines last at least 200,000 miles, an average of 12+ years, and staying on the road longer than they ever have.

Same for the batteries. Bottom line is that one should worry about battery longevity as much as one worried about ICE longevity. They are nearly identical.

 

[Roy2001]

In 2021, battery packs are about $100-120/kWh to make. So for a Mustang Mach-E ER, for example, that's about $10-12K.

Fast forward 9 years to 2030... battery production is likely 10 times that of 2021. Pure manufacturing scale and battery design improvement should push costs down... maybe to $40/kWh. Now your replacement battery costs $4K.

That is the material cost for car makers, not for end customers.

In order to have one sent to retailers, the cost would be more than doubled. No need to mention labor.

 

[Kiggulak]

Well to breathe some new discussion life into this thread. It’s a little off topic since it’s about Ford’s investment and development in solid state batteries. But interesting speculation on availability for the 2025 model update.

 

[greenne]

Oddly enough when I got into my Focus Electric this morning. I heard the repeated clicks of the high voltage contactor failing to engage. Usually a single louder clunk instead of the clicks. Dashboard would not illuminate and the headlights flickered. When I turned off the headlights the contactor closed and the dash illuminated and normal chimes that the car was ready to drive.

I reduced the load on the 12V and it was able to pull the contactor in.

A minute or two later Ford Sync emailed me to plug my car in and charge the 12V battery. This is the first sign that my 12V battery is failing. Last time I had a few weeks after the first "false start" before the 12V battery when down hard.

I drove to work parked without charging and at the end of the day my FFE started normally and I drove home to level 2 charging.

Moral of the story Ford has been charging the 12V battery with the traction battery since at least 2013.

I have a 2009 Escape Hybrid. Similar setup as the Focus Electric in that the "big battery" does the engine start(and acts as an alternator to charge the 12v), but it still has the 12v as a control. Now on my 3rd 12v battery(they seem to last about 5-6yrs for me)..it does the same thing. When the 12v goes bad..it goes bad quick without warning. You're lucky you got some sort of warning--usually the 12v fails suddenly in these things.

 

[WRS]

Same for the batteries. Bottom line is that one should worry about battery longevity as much as one worried about ICE longevity. They are nearly identical.

I guess if you say it over and over it becomes true?

 

[vandy1981]

I guess if you say it over and over it becomes true?

There are 1000s of fifteen-year-old ICE F150s on the road today. I'd bet there are zero operational Teslas that are that old

 

[GarageMahal]

There are 1000s of fifteen-year-old ICE F150s on the road today. I'd bet there are zero operational Teslas that are that old

Wondering how many of those 1000s are running original parts... Engine and transmission replacements are commonplace. Granted that a well maintained ICE will last a long time (my nearly 20 year old Marauder still runs like new although it is on its second fuel pump). I suspect that BEVs will ultimately prove to last longer as they have significantly fewer parts to wear out.

Regardless, we don't have the data to know but I am not worried.

 

[Fastnf]

The problem here as I see it is the assumption that the life time hours of an ICE engine is related to calander time. It is not. Its related to operational time. I have a 27 year old f 250 4x4 with just over 100k miles it runs fine and has never been apart. It degrades with hours of operation not calander time. The less I use it the longer it lasts in calender time, assuming I do regular maintenance. If we assume an average speed of 50 mile/ hr during operation that equates to 2000 hr or 83 days of operation.

A battery however degrades with calendar time, not use time. So if I use it sparingly it will still degrade in 10 to 12 years and there is nothing I can do to stop it.

That concerns me as I will need to replace the battery some time after 10-12 years. You may say that there may be after market batteries at that time, but I am not certain about that as currently we can't even get enough batteries for the new cars being fabricated and demand is only going to go up from here.

 

[Pedaldude]

There are 1000s of fifteen-year-old ICE F150s on the road today. I'd bet there are zero operational Teslas that are that old

Registration data is available, the average vehicle age is just over 12 years and a quarter of all vehicles registered are over 16 years old. I think that it would be safe to say that there are millions of F-150s either registered or sitting in a barn and drivable. I am sure most of them still have their original drivetrains as it's not as common anymore to rebuild or replace engines and transmissions.

The prototype 1st gen. Lotus based Tesla roadsters are reaching 15 years now and in two years, the early 2008 production models will be. I wonder if there are any that have their original batteries and how far they can go on a charge?

https://www.thedrive.com/tech/39687...-are-becoming-a-study-on-ev-battery-longevity

 

[EaglesPDX]

I guess if you say it over and over it becomes true?

Facts are worth repeating.

 

[biers]

I have 20 40 Ah 12v lithium batteries from used hospital equipment. They were charged and discharged nearly everyday. Manufactured in 2014 and used until early this year. 7 years of 24x7 use. They still have between 30 and 32 aH capacity. That’s 90%+ after 7 years of use. My 4 year old eGolf with 70k miles still has 95% the capacity of when I got it. I’m not at all worried about the Lightning.

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