Battery Replacement

OneLapper

Well-known member
First Name
Mark
Joined
Dec 3, 2019
Messages
389
Reaction score
751
Location
NE Conn
Vehicles
BMW 328d Sportswagon
Country flag
I have some experience repairing modern 350vdc battery packs for the Alta motorcycles. These packs are said to have been designed by ex-Tesla engineers.

Like the new structural 4680 battery packs, the Alta battery packs epoxy the cells into the cell holder. The bottom of the module is an aluminum plate which is the heat sink. If a cell fails (haven't seen one individual cell fail yet), it's effectively impossible to remove and replace that cell without destroying the module.

The modules (4 in all, like current Teslas) have the cell grouped in parallels of 6 cells. If any wire bond breaks on any of the cells in the parallel group, all 6 cells within that P group are affected. In this case, the cells are no longer electrically connected to the module therefore they do not charge or discharge.

If someone noticed this failure soon enough, and they were able to physically repair the broken wire bond, the cells would resume their work and little damage would be done. What I have observed is that affected module falls out of balance with the other three good modules due to the 6 cells that are not charging and discharging. Over time that module slightly overcharges and over discharges.

With the new structural 4680 battery packs, there doesn't appear to be any "modules", therefore a single wire bond failure to a parallel group (unknown quantity of cells at this point), would result in pack with a lower overall voltage, and result in less range. As an owner, we would have no indication of a wire bond failure, save for a reduction in range.

Since the Tesla battery packs are glued and screwed together, they are not intended to be fixed. The 4680 pack will be "less" repairable than the existing 4 module Tesla packs. I've stated before, I doubt there will any way to "fix" a Tesla 4680 structural battery pack. And since there are no modules (that we know of at this point), the EV West's of the world can't pull the modules of a wrecked Tesla and sell the good ones for DIYers.

I don't know if any independent diagnostic software is available for Tesla's battery packs, but it would be nice to have. I'd love to be able to see the health of each parallel group in a Tesla pack.
Advertisement

 
Last edited:

rr6013

Well-known member
First Name
Rex
Joined
Apr 22, 2020
Messages
676
Reaction score
600
Location
Piedras Gordas Panama
Website
shorttakes.substack.com
Vehicles
1997 Tahoe 2 door 4x4
Occupation
Retired software developer and heavy commercial design builder
Country flag
I don't see any reason to replace a battery cell rather than a module.
This isn’t directed at you personally. In 1997 Chevrolet built cars for which it was required to provide parts in the US for 8yrs. This is pinnacle Chevrolet at a moment(40yrs)where its automotive prowess came together in its highest embodiment.

Carry costs for all those parts was a burden, especially as its reliability and endurance was responsible for NOS(new old stock) parts in-place. Chevrolet changed its parts business from individual pieces to assemblies. No longer could customers replace a windshield washer pump that had frozen and cracked. From 1998 onward customers had to buy the entire windshield washer assembly that included the pump, water bottle and cap. Chevrolet stocked 3/4ths few part numbers and quadrupled averaged sale over the counter.

Public accepted the practice, parts price increases and the cost of cars followed. Its not all bad, but today its ridiculous to the point of bankrupt, the idea that saved auto manufacturers continues to drive TCO(total cost of ownership).

Insurance companies total a car that’s repairable based on the cost of parts assemblies required. In 1997 insurance required five qbody panels damaged to total. Today simply coming within ~60% wholesale cost used totals a car.

Replacing complete assemblies parts mentality is ICE legacy. BEV structural battery pack is easily 40% cost new. Every BEV will total that blows a single cell in a module inside battery packs. That history is ”sunk cost” amortized over all insurance holders rates if assemblies over parts mentality sticks to BEV.

Take a look how a BEV mechanic view Tesla, Tesla electronics and battery cells inside its battery pack modules. It may save your Tesla.

 

Akgolf

Well-known member
First Name
Jimmy
Joined
May 26, 2020
Messages
146
Reaction score
323
Location
Jones, OK
Vehicles
2016 Nissan Leaf and 2016 Toyota Prius V.
Occupation
Retired Computer Programmer, USAF
Country flag

CybertruckAgent

Well-known member
First Name
Bob
Joined
Dec 30, 2020
Messages
67
Reaction score
88
Location
Nashville
Vehicles
Cybertruck Tri-motor
Occupation
Realtor
Country flag
I remember reading those articles. he past 1,333,333km recently. However he has also gone through 4 motors and 3 battery packs.

Both the motors and the battery packs have improved, but we haven't reached the million mile battery yet, hopefully the cybertruck is close
To be fair I don’t think very many vehicles are “million mile” built at all. I think a lot of people are expecting an un-realistic amount of long term reliability compared to their expectations of ICE alternatives. For example, when’s the last time you saw a thread regarding full power train replacement cost on a Silverado whose engine is only warranted for 5 years or 60k miles? I find it a fascinating dichotomy.
 

rr6013

Well-known member
First Name
Rex
Joined
Apr 22, 2020
Messages
676
Reaction score
600
Location
Piedras Gordas Panama
Website
shorttakes.substack.com
Vehicles
1997 Tahoe 2 door 4x4
Occupation
Retired software developer and heavy commercial design builder
Country flag
To be fair I don’t think very many vehicles are “million mile” built at all. I think a lot of people are expecting an un-realistic amount of long term reliability compared to their expectations of ICE alternatives. For example, when’s the last time you saw a thread regarding full power train replacement cost on a Silverado whose engine is only warranted for 5 years or 60k miles? I find it a fascinating dichotomy.
Million mile battery life is subtext for a “working” part. Indeed it will probably still charge but useful range will not be any guarantee.

I expect Tesla to guarantee backward vehicle compatibility over improvements, upgrades, revisions and changes over the million mile lifetime to support its million mile guaranteed battery.

Tesla EV Interior, trim, glass, tires, suspension, brakes and electronics all are consumables that replace at intervals. Cybertruck $400 invisible door handles, $900 PDU, $2400 Vault door mechanism, $1900 bio-warfare HVAC, $3000 Battery conditioner, $4500 InfoTainment computer, $1400 dynamic suspension, inverter, on-board air; all electronic - all consumables.

Grey areas are IDRA castings and ARMOR glass which traditionally are failure-prone consumables in ICE applications but BEV could be insured or self-insured after warrantee period. Tesla might still be million mile legally liable for them as structural components.
 

Crissa

Well-known member
First Name
Crissa
Joined
Jul 8, 2020
Messages
5,891
Reaction score
7,727
Location
Santa Cruz
Vehicles
2014 Zero S, 2013 Mazda 3
Country flag
I have come across a company on YouTube that actually has replaced individual cells. Personally though I’m not concerned about it.
They're fibbing. They remove cells from the module array, they don't replace them.

And the original Roadster battery is pretty much nothing like the current batteries or the future ones.

Future, not current designs. When this is possible and practice, you will think back and be amazed. Don’t let facts and figures get in the way with passion. 😀
Cell imbalance just kills the concept.

Maybe in a 4680 array, but we're seeing module imbalance lower overall lifetime, so... I don't think it'll work out.

Magic batteries, maybe. Some heretofore unknown chemistry.

-Crissa
 
Last edited:

Faffle

Well-known member
Joined
Apr 2, 2020
Messages
55
Reaction score
122
Location
Portland Oregon
Vehicles
Kia Soul ev
Country flag
How hard do you think it will be to replace battery? With the SS and motor designed for a lot of miles, the only big cost will be battery potentially....how much/hard do you think?
I'm going to guess that you won't be able to replace them as they are part of the frame. That said, i expect them to outlast the rest of the components with all the talk about million mile batteries. I'd hedge my bets for future years by buying more range than you need!

On a side note, my extended family has two kia Soul ev's(2015,2017). 10 year warranty on the battery and they both lasted the same, 4.5 years and only 40k miles. I keep reading about how Tesla batteries last longer but i've got some fears. At least Kia has a great warranty on it, i wish Tesla did.
 

Cybertruck Hawaii

Well-known member
First Name
Michael
Joined
Apr 24, 2021
Messages
102
Reaction score
43
Location
Honolulu
Vehicles
Sienna
Occupation
Retired
Country flag
I’m not messing around with a 600 vote battery just to save a few bucks. That’s a job for the professional service technician.
 

Diehard

Well-known member
First Name
D
Joined
Dec 5, 2020
Messages
1,120
Reaction score
2,034
Location
U.S.A.
Vehicles
Olds Aurora V8, Saturn Sky redline, Frontier, CT2
Country flag
This thread is making me feel a little better about driving an 18 year old ICE truck with original gas tank. If it ever goes bad, I doubt I will have to spend $16K+ to replace it.

To those that are loading their keyboards with angry words getting ready to shoot, all I am saying is that if Toyota came out with an affordable million mile range FREV (Fusion Reactor Electric Vehicle) with a tank I could fill up with sea water I may pick that over a battery pack.
 

Tinker71

Well-known member
First Name
Ray
Joined
Aug 8, 2020
Messages
267
Reaction score
304
Location
Utah
Vehicles
1976 electric conversion bus
Occupation
Project Manager
Country flag
Since the Tesla battery packs are glued and screwed together, they are not intended to be fixed. The 4680 pack will be "less" repairable than the existing 4 module Tesla packs. I've stated before, I doubt there will any way to "fix" a Tesla 4680 structural battery pack. And since there are no modules (that we know of at this point), the EV West's of the world can't pull the modules of a wrecked Tesla and sell the good ones for DIYers.

[/QUOTE]

I can't wait for the battery pack design to be made available. The BMS system must be amazing, if there is no way to replace a single cell I am going to guess that the pack might be sized slightly larger than quoted and then limited by software to compensate.

When you think about warranties, I am feeling more confident that you will at least be able to replace the whole pack. Could you imagine loosing 2 cells on the same series. Tesla my have to total the entire vehicle.

As many have stated it will be a slab of epoxy with lots of perimeter attachment points. That said I think it would be possible to bisect that slab with a tounge and grove joint. However that does not appear to be the case based on the sneak peak that Sandy M got.
 

Faffle

Well-known member
Joined
Apr 2, 2020
Messages
55
Reaction score
122
Location
Portland Oregon
Vehicles
Kia Soul ev
Country flag
The Tesla battery warranty is longer.

-Crissa
What is the current Tesla battery warranty? Last i took note of Tesla they limited the mileage and it was only 8 years. Last i looked the Kia one was 10 years, unlimited miles, if it drops to 70% soh they replace the battery, not prorated. Tesla seems to have the better batteries, you'd think they would be able to have the better warranty too.
 

Crissa

Well-known member
First Name
Crissa
Joined
Jul 8, 2020
Messages
5,891
Reaction score
7,727
Location
Santa Cruz
Vehicles
2014 Zero S, 2013 Mazda 3
Country flag
The Kia traction battery is only 7 years in the EU (10 in the US) and fewer miles (100k) and requires higher degradation than Tesla, 70% vs 80%. But the Niro isn't the Soul, either. The Soul has a battery like the Leaf, the Niro has a battery like the Bolt.

I don't know of an unlimited miles warranty.

-Crissa
 

John K

Well-known member
First Name
John
Joined
Jan 2, 2020
Messages
971
Reaction score
1,523
Location
Los Angeles
Vehicles
Volt, CT reserve day 2
Country flag
Magic batteries, maybe. Some heretofore unknown chemistry.
There is a Forest Gump quote in there about legs. I like the term, unbelievable technology. It will be ready with the hover feature in my next CT
 

lancethibault

Well-known member
Joined
May 23, 2020
Messages
217
Reaction score
276
Location
Colorado Springs
Vehicles
13' F150, 17' Explorer, 13' Cruz, CT3 RN112841395
Occupation
USSF
Country flag
The Kia traction battery is only 7 years in the EU (10 in the US) and fewer miles (100k) and requires higher degradation than Tesla, 70% vs 80%. But the Niro isn't the Soul, either. The Soul has a battery like the Leaf, the Niro has a battery like the Bolt.

I don't know of an unlimited miles warranty.

-Crissa
What Tesla battery warranty is to 80% vs 70% of original capacity?

This is directly from the Tesla Site.

Battery and Drive Unit Warranty
The Battery and Drive Unit in your vehicle are covered for a period of:

Model S
Model X
8 years or 150,000 miles, whichever comes first, with minimum 70% retention of Battery capacity over the warranty period.
Model 3 Standard Range8 years or 100,000 miles, whichever comes first, with minimum 70% retention of Battery capacity over the warranty period.
Model 3 Long Range
Model 3 Performance
Model Y Long Range
Model Y Performance
8 years or 120,000 miles, whichever comes first, with minimum 70% retention of Battery capacity over the warranty period.


These warranties cover the repair or replacement necessary to correct defects in the materials or workmanship of any parts manufactured or supplied by Tesla, which occur under normal use.

So the way I read this, Tesla offer more miles, but Kia offers more time and both use the 70% rule.
 
Advertisement

 
Advertisement
Top