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Battery Degradation and Care Worries Overblown?
- Thread starter TM3RWD
- Start date
Yeah people hear different bits of advice and tend to go overboard.
People who think they need to always charge to 100% at a fast charger because they have LFP and think it will cause harm if they don't are the ones that irk me
People who think they need to always charge to 100% at a fast charger because they have LFP and think it will cause harm if they don't are the ones that irk me
Good video, although he should have added that while LFP batteries have a number of benefits over NMC/NCA batteries, their biggest shortcoming is lower energy density. So the longest-range EVs still need NCA.
Punchbuggy
Member
Thanks for the post, and I agree with Vostock - he needed to expand on LFP a little more, and perhaps even comment on the next-gen LFP as an example of battery chemistry improving each year or so. The point being it's still relatively early days for the tech and it's getting better.
That said, good video, and if you just jump to the 22 minute mark you'll hear the most relevant message of the story.
That said, good video, and if you just jump to the 22 minute mark you'll hear the most relevant message of the story.
I think the one thing I've learnt is that age is a more important factor than mileage. In fact it seems the low mileage cars can encounter more problems sooner.
The large drive units are particularly problematic. If you just look at the high mileage cars such as the 1.9million km car needing 14 motors, then you'd think average 135,000km/motor. I'm now on my 3rd motor in 74,000km for an average of only 37,000km/motor. If you read comments on TMC from people rebuilding the motors then it seems to be a consistent pattern with many failures occurring despite low mileage.
The same is true for battery degradation, with age having a much bigger impact than mileage. Even the stat quoted in the video has changed (the 10% degradation after 200,000 miles). This was true at one point, but in the most recent report we now see an average 12% degradation for 200,000 miles. Obviously the mileage is the exact same, but what has changed is the average age of the fleet. And since degradation is more closely tied to age rather than mileage, this has increased the stat.
It's dangerous to assume that because you are driving much less than the high mileage cars that you will see a much longer life from the components. I'd always suggest working out the $ cost in a worst case scenario (having to replace a drive unit and/or battery out of warranty). If it makes you too uncomfortable then be sure to replace the car before warranty expires.
The newer cars might fare better, but then again I'm starting to hear degradation numbers from the early model 3's delivered here that are trending worse than the older S & X's. It might be why Tesla had to drop the max daily charge level for these cars from 90% to 80%.
The large drive units are particularly problematic. If you just look at the high mileage cars such as the 1.9million km car needing 14 motors, then you'd think average 135,000km/motor. I'm now on my 3rd motor in 74,000km for an average of only 37,000km/motor. If you read comments on TMC from people rebuilding the motors then it seems to be a consistent pattern with many failures occurring despite low mileage.
The same is true for battery degradation, with age having a much bigger impact than mileage. Even the stat quoted in the video has changed (the 10% degradation after 200,000 miles). This was true at one point, but in the most recent report we now see an average 12% degradation for 200,000 miles. Obviously the mileage is the exact same, but what has changed is the average age of the fleet. And since degradation is more closely tied to age rather than mileage, this has increased the stat.
It's dangerous to assume that because you are driving much less than the high mileage cars that you will see a much longer life from the components. I'd always suggest working out the $ cost in a worst case scenario (having to replace a drive unit and/or battery out of warranty). If it makes you too uncomfortable then be sure to replace the car before warranty expires.
The newer cars might fare better, but then again I'm starting to hear degradation numbers from the early model 3's delivered here that are trending worse than the older S & X's. It might be why Tesla had to drop the max daily charge level for these cars from 90% to 80%.
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I've not heard that the M3/Y have drive motor problems like you describe.
How long have you owned the P85D?
Model S. To be fair the last motor was replaced in 2017 so it's had a reasonable life although far less than a typical ICE motor.
The car is out of warranty so it was $10k to replace. Since I was paying they said it was ok to order in a new U revision motor which has a fix for the coolant leak problem. Hopefully it proves more reliable long term.
They did originally quote $10k for a reman T revision motor. I was very unhappy with the thought of paying that amount only to get a used motor (that was reman'd) and had the same design flaw and would likely need replacing again in the coming years. Was pleasantly surprised a brand new U revision would be the same price.
Don't disagree with a Tesla 3.
But it certainly is an issue with say early Nissan Leafs and their passively cooled batteries where some have sub 100km range.
And stories about one EV tend to pervade others.
The other big issue with cars over say eight years (or high km) is the risk and cost of a battery pack failure.
No matter how small the risk, a buyer at that point is always going to think about that because of the outsized cost to them Vs the value of the vehicle at that time (maybe someone comes up with some third party insurance to mitigate this after inspection??)
But it certainly is an issue with say early Nissan Leafs and their passively cooled batteries where some have sub 100km range.
And stories about one EV tend to pervade others.
The other big issue with cars over say eight years (or high km) is the risk and cost of a battery pack failure.
No matter how small the risk, a buyer at that point is always going to think about that because of the outsized cost to them Vs the value of the vehicle at that time (maybe someone comes up with some third party insurance to mitigate this after inspection??)
All of the Australian 3/Y fleet are still on their 8 yr battery warranty. Some of the 3 fleet are coming to the end of the 4 year warranty basic. So there is no info re depreciation at the 8 year end of battery mark in the Australian market
Any intel on depreciation re Teslas in other markets with expired battery warranty?
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Well other than some high km models.
No US models are 8 years yet either.
And it's not necessarily and 8 years point. Suspect people will have similar concerns buying a 7yo car for example.
I think its going to be km driven as a ratio of warranted km + calendar age + supercharging activity
If we convert this into km driven, 1 km out of an older battery is effectively >1km in a newer battery for calculating resale value.
Maybe best confirmed by a Service mode battery test?. Then there is the minimum SoC which may be above 0%.
The available range in a degraded battery is defined by the cell with the lowest voltage even though the other cells are OK and at low SoC some degraded cells may ?suddenly drop voltage making range estimations at low SoC problematic.. I'm not sure at what "battery level" is this significant - I've heard significant in packs with more than 20% degradation.
If we convert this into km driven, 1 km out of an older battery is effectively >1km in a newer battery for calculating resale value.
Maybe best confirmed by a Service mode battery test?. Then there is the minimum SoC which may be above 0%.
The available range in a degraded battery is defined by the cell with the lowest voltage even though the other cells are OK and at low SoC some degraded cells may ?suddenly drop voltage making range estimations at low SoC problematic.. I'm not sure at what "battery level" is this significant - I've heard significant in packs with more than 20% degradation.
It may be a perverse incentive for EV manufacturers to keep Battery pack replacement costs high??
Ahh right. There'd be quite a few Model 3s in Australia now up above the 100,000km mark and I haven't heard much about motor replacements, so those units seem to be lasting better. Probably include a lot of learnings from the early Model S motors.
I am delighted with the battery on my MIC 3LR. 28 months old, 20,000kms, capacity lost 1.6kwhrs from 74.5kwhrs, 97.8% SOH. 78% AC charging so far.
Our 2018 Renault Zoe has averaged 2% drop of SOH per year and is at 90% (from an initial 101%) after 5.5yrs and 30,000kms.
Cars only go to 100% charge before a long trip.
Neither does large mileage and the Tesla is doing better than the Zoe which does have battery temperature management, but not as sophisticated as Tesla.
There are now a very large number of 3s out there in the world and I do not see many complaints about batteries. Hopefully that is a good sign!
Our 2018 Renault Zoe has averaged 2% drop of SOH per year and is at 90% (from an initial 101%) after 5.5yrs and 30,000kms.
Cars only go to 100% charge before a long trip.
Neither does large mileage and the Tesla is doing better than the Zoe which does have battery temperature management, but not as sophisticated as Tesla.
There are now a very large number of 3s out there in the world and I do not see many complaints about batteries. Hopefully that is a good sign!
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