Battery Care required for longevity?
Discussion
I saw this in response to another post...
Which EVs need battery care from the users?
from another thread said:
Unless it's a couple of specific cars then don't charge generally to over 85% daily unless you're going on a trip. If you are going on a trip charge to 100% as close to your departure as possible.
Try not leave it at very low states of charge, less than 15%.
Frequent full charges and very low states of charge aren't great for battery longevity as a general rule.
I thought that most cars had battery management that took care of this, and that is why there's a difference between actual and usable battery capacity?Try not leave it at very low states of charge, less than 15%.
Frequent full charges and very low states of charge aren't great for battery longevity as a general rule.
Which EVs need battery care from the users?
Your battery will outlast the rest of the vehicle, generally speaking, with surprisingly less degradation then you might expect.
Whilst those tips are not wrong (and fast charging is less ideal then more reasonable charging speeds) you don't need to over think it. Personally I'd avoid fast charging unless needed, but I definitely wouldn't be over thinking the rest of it.
The automotive industry is quickly realising these batteries are significantly more over engineered/robust then expected from a degradation point of view.
I don't drive am EV, but my job has me as somewhat of a SME in related areas.
Whilst those tips are not wrong (and fast charging is less ideal then more reasonable charging speeds) you don't need to over think it. Personally I'd avoid fast charging unless needed, but I definitely wouldn't be over thinking the rest of it.
The automotive industry is quickly realising these batteries are significantly more over engineered/robust then expected from a degradation point of view.
I don't drive am EV, but my job has me as somewhat of a SME in related areas.
If you’re planning on keeping a car forever, then maybe think about battery management.
If you’re going to keep it between three and five years don’t bother, as it makes very little difference.
You have to be doing huge milage in the life of the car(150,000+)for battery management to make any real difference.
Data shows at 150,000 miles of a Tesla battery you may lose 5% of range.
If you’re going to keep it between three and five years don’t bother, as it makes very little difference.
You have to be doing huge milage in the life of the car(150,000+)for battery management to make any real difference.
Data shows at 150,000 miles of a Tesla battery you may lose 5% of range.
Whilst you may get away with charging to 100% every charge, unless you need the range, why bother? It’s not as if setting an 85% charge cap takes any of my time (it’s what my Model 3 Performance is set to). Why not reduce the number of full charge cycles, it’s not going to do any harm and will likely do some good in the long term.
As for letting the battery run low, again, unless you are eeking out every last mile of range, why would you? Apart from the day I collected my car and was at the mercy of the poor SoC (when it ran to 19% on my way to the nearest Supercharger), I’ve never let the battery run below 20% again, most of the time it’s not really getting lower than 50% (just down to my usage pattern). As we come into colder nights and mornings, I can see this figure increasing as I’m more likely to plug in every night (for preconditioning off the mains more than charging), which would likely bring my low/high for commuting days to around 70%/85%.
As for letting the battery run low, again, unless you are eeking out every last mile of range, why would you? Apart from the day I collected my car and was at the mercy of the poor SoC (when it ran to 19% on my way to the nearest Supercharger), I’ve never let the battery run below 20% again, most of the time it’s not really getting lower than 50% (just down to my usage pattern). As we come into colder nights and mornings, I can see this figure increasing as I’m more likely to plug in every night (for preconditioning off the mains more than charging), which would likely bring my low/high for commuting days to around 70%/85%.
skilly1 said:
If you’re planning on keeping a car forever, then maybe think about battery management.
If you’re going to keep it between three and five years don’t bother, as it makes very little difference.
You have to be doing huge milage in the life of the car(150,000+)for battery management to make any real difference.
Data shows at 150,000 miles of a Tesla battery you may lose 5% of range.
Exactly. I don't know why people obsess over this stuff so much when the evidence shows that the batteries can easily outlast the life of a typical car anyway... And with only minor deg.If you’re going to keep it between three and five years don’t bother, as it makes very little difference.
You have to be doing huge milage in the life of the car(150,000+)for battery management to make any real difference.
Data shows at 150,000 miles of a Tesla battery you may lose 5% of range.
People don't seem to understand that the BMS is charge cycling groups of cells in turn within the battery pack in a close to perfect manner. The fact the owner sees 80% overall and stops charging doesn't mean any or all cells are actually at 80%... The clusters of cells will each be at whatever point of charge the BMS decides is optimal.
Literally the only difference not charging to 100% makes is that you're giving the BMS a little more headroom to work which could marginally reduce degredation over an extended period. The reason it's only going to make a marginal difference is due to there already being headroom over and above what is displayed as '100%' charged - the manufacturers have made their own calculation as to what that extra capacity should be for the BMS to do its job and their data and calcs are going to carefully done as they have to warranty the battery.
There have been some examples of early EV's where the battery hasn't lasted well at all, but so far as I know those have all been identified as a specific problem with the battery or BMS which has since been addressed.
paradigital said:
Whilst you may get away with charging to 100% every charge, unless you need the range, why bother? It’s not as if setting an 85% charge cap takes any of my time (it’s what my Model 3 Performance is set to). Why not reduce the number of full charge cycles, it’s not going to do any harm and will likely do some good in the long term.
As for letting the battery run low, again, unless you are eeking out every last mile of range, why would you? Apart from the day I collected my car and was at the mercy of the poor SoC (when it ran to 19% on my way to the nearest Supercharger), I’ve never let the battery run below 20% again, most of the time it’s not really getting lower than 50% (just down to my usage pattern). As we come into colder nights and mornings, I can see this figure increasing as I’m more likely to plug in every night (for preconditioning off the mains more than charging), which would likely bring my low/high for commuting days to around 70%/85%.
I tend to charge to between 90-100% each night, depending on how many cheap rate hours octopus deliver... As for letting the battery run low, again, unless you are eeking out every last mile of range, why would you? Apart from the day I collected my car and was at the mercy of the poor SoC (when it ran to 19% on my way to the nearest Supercharger), I’ve never let the battery run below 20% again, most of the time it’s not really getting lower than 50% (just down to my usage pattern). As we come into colder nights and mornings, I can see this figure increasing as I’m more likely to plug in every night (for preconditioning off the mains more than charging), which would likely bring my low/high for commuting days to around 70%/85%.
Why do I risk such a high level of charge? Because the evidence suggests the effect on degredation is so little that it's not worth worrying about. Starting a day with less charge however could become an inconvenience if an unexpected trip has to be made.
ETA: also if I charged between 20-85% as you suggest, I'd have paid for a very expensive battery pack that I didn't get any use from.
Edited by TheDeuce on Wednesday 12th October 09:14
TheRainMaker said:
Always charge mine to 100%
As has been said, why pay for the range and then not use it?
The car was sold with a range from 100% and nothing was mentioned about you should only charge it to 80%
Longevity, I don't own it, so really don't care
On the point of paying for range which you then don't use... Thinking about it it makes even less sense to try and 'save' the batteries life. If I were to keep my car for 10 years/10k miles and I charged it only to 85% then I might have a few more % capacity as a result. But that's just silly if the only way to get that extra few % is to spend ten years NOT getting the use of the first and last 15% As has been said, why pay for the range and then not use it?
The car was sold with a range from 100% and nothing was mentioned about you should only charge it to 80%
Longevity, I don't own it, so really don't care
TheRainMaker said:
Always charge mine to 100%
As has been said, why pay for the range and then not use it?
The car was sold with a range from 100% and nothing was mentioned about you should only charge it to 80%
Longevity, I don't own it, so really don't care
Never understood that statement. If you're doing a trip that requires 100% charge then fair enough, but if running around doing 30-50 miles per day 99% of the time as most do it makes absolutely no difference whether you charge to 50%, 80% or 100% overnight as you aren't using the potential range anyway?As has been said, why pay for the range and then not use it?
The car was sold with a range from 100% and nothing was mentioned about you should only charge it to 80%
Longevity, I don't own it, so really don't care
TheDeuce said:
On the point of paying for range which you then don't use... Thinking about it it makes even less sense to try and 'save' the batteries life. If I were to keep my car for 10 years/10k miles and I charged it only to 85% then I might have a few more % capacity as a result. But that's just silly if the only way to get that extra few % is to spend ten years NOT getting the use of the first and last 15%
As above, what difference does it make the rest of the time if you are using that first and last 15% on trips where it's actually needed?I'd worry more about leaving for long periods at very high or very low states of charge than regularly charging to 100%. But then I'm used to RC car lipo batteries that don't have their own BMS or any buffers and need bringing to storage voltage before you put them away.
I can get about 40% into the battery on my 4 hour off-peak window, so tend to let the battery go down to 30-40% before charging. If I know I've got a long trip coming up I'll charge two nights in a row to get it up to 100%.
I can get about 40% into the battery on my 4 hour off-peak window, so tend to let the battery go down to 30-40% before charging. If I know I've got a long trip coming up I'll charge two nights in a row to get it up to 100%.
SWoll said:
TheRainMaker said:
Always charge mine to 100%
As has been said, why pay for the range and then not use it?
The car was sold with a range from 100% and nothing was mentioned about you should only charge it to 80%
Longevity, I don't own it, so really don't care
Never understood that statement. If you're doing a trip that requires 100% charge then fair enough, but if running around doing 30-50 miles per day 99% of the time as most do it makes absolutely no difference whether you charge to 50%, 80% or 100% overnight as you aren't using the potential range anyway?As has been said, why pay for the range and then not use it?
The car was sold with a range from 100% and nothing was mentioned about you should only charge it to 80%
Longevity, I don't own it, so really don't care
TheDeuce said:
On the point of paying for range which you then don't use... Thinking about it it makes even less sense to try and 'save' the batteries life. If I were to keep my car for 10 years/10k miles and I charged it only to 85% then I might have a few more % capacity as a result. But that's just silly if the only way to get that extra few % is to spend ten years NOT getting the use of the first and last 15%
As above, what difference does it make the rest of the time if you are using that first and last 15% on trips where it's actually needed?It's just not worth worrying about a tiny bit of extra deg when you can just keep it charged and not worry about it full stop.
SWoll said:
TheRainMaker said:
Always charge mine to 100%
[b]As has been said, why pay for the range and then not use it?[/b[
The car was sold with a range from 100% and nothing was mentioned about you should only charge it to 80%
Longevity, I don't own it, so really don't care
Never understood that statement. If you're doing a trip that requires 100% charge then fair enough, but if running around doing 30-50 miles per day 99% of the time as most do it makes absolutely no difference whether you charge to 50%, 80% or 100% overnight as you aren't using the potential range anyway?[b]As has been said, why pay for the range and then not use it?[/b[
The car was sold with a range from 100% and nothing was mentioned about you should only charge it to 80%
Longevity, I don't own it, so really don't care
My car is generally charged at the office to 100% on Friday, which will noramlly last till Monday without charging at home, it is then charged on Monday at the office which will last until Friday.
Minimal faff, minimal cost to me
sjg said:
I'd worry more about leaving for long periods at very high or very low states of charge than regularly charging to 100%. But then I'm used to RC car lipo batteries that don't have their own BMS or any buffers and need bringing to storage voltage before you put them away.
I can get about 40% into the battery on my 4 hour off-peak window, so tend to let the battery go down to 30-40% before charging. If I know I've got a long trip coming up I'll charge two nights in a row to get it up to 100%.
I think that's a good example of where the supposed battery cycling wisdom come from. For a huge part of our lives we have had li-ion powered devices that actually do suffer battery Deg if not we'll managed by us, the user. But of course those devices don't have a BMS that is programmed to cycle the specific cells used as ideally as possible - far more diligently than a human trying to keep track of usage and when to cycle and optimum %'s etc..I can get about 40% into the battery on my 4 hour off-peak window, so tend to let the battery go down to 30-40% before charging. If I know I've got a long trip coming up I'll charge two nights in a row to get it up to 100%.
TheDeuce said:
I think that's a good example of where the supposed battery cycling wisdom come from. For a huge part of our lives we have had li-ion powered devices that actually do suffer battery Deg if not we'll managed by us, the user. But of course those devices don't have a BMS that is programmed to cycle the specific cells used as ideally as possible - far more diligently than a human trying to keep track of usage and when to cycle and optimum %'s etc..
Some truth in that.When you charge a new car to '100%' it's probably not charging the battery to 100%.
It's charging to a level where the makers have weighed off range against their battery warranty.
Likewise it tells you a range to 'zero' which is not based on real flat as Norfolk zero', it's based on a prudent level of discharge.
They've done the sums and the research to be fairly sure that 99% of their cars will meet their warranty performance of 8 years and 100k miles or whatever before the range drops more than 20% or something.
This also has the side effect of lots of happy people with 2 and 3 year old cars saying 'the range hasn't decreased at all'.
This keeps the market for used EVs good and all the people who matter are happy.
As the car gets older, the margins will be smaller, and the BMS will compromise between giving a reasonable range and eeking out battery life.
By the time the driver starts noticing significantly less range, the battery is probably a fair way down its curve.
By this point the car maker has got one eye on the prospect of selling another new car.
Towards the end of the game, the car maker has no interest in the wellbeing of shed drivers and wants to see cars which are no longer an income stream recycled. That's balanced by wanting to keep their reputation of course. But there are many other industries where manufacturers like to remove old goods from the market.
Bear in mind that the BMS is partly a whole stack of software which may be 'updated' through the car's life.
Also bear in mind that this approach applies to IC vehicles, increasingly so as time goes on.
I don't think it's worth the ordinary user over thinking it, unless maybe they are doing very high miles or low miles or extreme range.
TheDeuce said:
Exactly. I don't know why people obsess over this stuff so much when the evidence shows that the batteries can easily outlast the life of a typical car anyway... And with only minor deg.
People don't seem to understand that the BMS is charge cycling groups of cells in turn within the battery pack in a close to perfect manner. The fact the owner sees 80% overall and stops charging doesn't mean any or all cells are actually at 80%... The clusters of cells will each be at whatever point of charge the BMS decides is optimal.
Literally the only difference not charging to 100% makes is that you're giving the BMS a little more headroom to work which could marginally reduce degradation over an extended period. The reason it's only going to make a marginal difference is due to there already being headroom over and above what is displayed as '100%' charged - the manufacturers have made their own calculation as to what that extra capacity should be for the BMS to do its job and their data and calcs are going to carefully done as they have to warranty the battery.
There have been some examples of early EV's where the battery hasn't lasted well at all, but so far as I know those have all been identified as a specific problem with the battery or BMS which has since been addressed.
Haha, I certainly don't obsess over this stuff as it was me being quoted here. But generally I personally follow this as I own my car and want to be reasonably kind to it. That said when I need to which is quite often I charge to 100% and over the last 3 months about 80% of my charging has been DC fast charging.People don't seem to understand that the BMS is charge cycling groups of cells in turn within the battery pack in a close to perfect manner. The fact the owner sees 80% overall and stops charging doesn't mean any or all cells are actually at 80%... The clusters of cells will each be at whatever point of charge the BMS decides is optimal.
Literally the only difference not charging to 100% makes is that you're giving the BMS a little more headroom to work which could marginally reduce degradation over an extended period. The reason it's only going to make a marginal difference is due to there already being headroom over and above what is displayed as '100%' charged - the manufacturers have made their own calculation as to what that extra capacity should be for the BMS to do its job and their data and calcs are going to carefully done as they have to warranty the battery.
There have been some examples of early EV's where the battery hasn't lasted well at all, but so far as I know those have all been identified as a specific problem with the battery or BMS which has since been addressed.
I think as a rule of thumb with most current EV's is not a bad one but I don't sweat it at all, and if my car was leased I would give zero f***s.
OutInTheShed said:
TheDeuce said:
I think that's a good example of where the supposed battery cycling wisdom come from. For a huge part of our lives we have had li-ion powered devices that actually do suffer battery Deg if not we'll managed by us, the user. But of course those devices don't have a BMS that is programmed to cycle the specific cells used as ideally as possible - far more diligently than a human trying to keep track of usage and when to cycle and optimum %'s etc..
Some truth in that.When you charge a new car to '100%' it's probably not charging the battery to 100%.
It's charging to a level where the makers have weighed off range against their battery warranty.
Likewise it tells you a range to 'zero' which is not based on real flat as Norfolk zero', it's based on a prudent level of discharge.
They've done the sums and the research to be fairly sure that 99% of their cars will meet their warranty performance of 8 years and 100k miles or whatever before the range drops more than 20% or something.
This also has the side effect of lots of happy people with 2 and 3 year old cars saying 'the range hasn't decreased at all'.
This keeps the market for used EVs good and all the people who matter are happy.
As the car gets older, the margins will be smaller, and the BMS will compromise between giving a reasonable range and eeking out battery life.
By the time the driver starts noticing significantly less range, the battery is probably a fair way down its curve.
By this point the car maker has got one eye on the prospect of selling another new car.
Towards the end of the game, the car maker has no interest in the wellbeing of shed drivers and wants to see cars which are no longer an income stream recycled. That's balanced by wanting to keep their reputation of course. But there are many other industries where manufacturers like to remove old goods from the market.
Bear in mind that the BMS is partly a whole stack of software which may be 'updated' through the car's life.
Also bear in mind that this approach applies to IC vehicles, increasingly so as time goes on.
I don't think it's worth the ordinary user over thinking it, unless maybe they are doing very high miles or low miles or extreme range.
And the evidence so far is that whilst manufacturers allow for 20% or whatever in their battery warrantee, the reality is that most early examples seem to live beyond the warranty period with less range deg than promised anyway - and are still perfectly useable day to day cars.
Another thing to think about is that we could all make ICE's last longer and lose less efficiency over the years if we worried about driving them as cautiously and gently as some talk of the 'best' way to charge their EV.. but few do that, especially not those on PH - outside of the classic car section that is.
At the end of the day, they're all cars and all built to survive a working life, in the knowledge that people generally won't always operate and maintain them in the most idealistic manner. They're built for humans!
RobbyJ said:
Haha, I certainly don't obsess over this stuff as it was me being quoted here. But generally I personally follow this as I own my car and want to be reasonably kind to it. That said when I need to which is quite often I charge to 100% and over the last 3 months about 80% of my charging has been DC fast charging.
I think as a rule of thumb with most current EV's is not a bad one but I don't sweat it at all, and if my car was leased I would give zero f***s.
As I understand it heavy use of DC charging is about the most damaging thing you can do - yet still there are legion old Tesla's out there that were sold with unlimited free fast charging so I'm guessing they've been DC charged almost exclusively..I think as a rule of thumb with most current EV's is not a bad one but I don't sweat it at all, and if my car was leased I would give zero f***s.
Edited by TheDeuce on Wednesday 12th October 14:29
With my first EV, a BMW i3, I charged to 100% for every work day and used it down to 2% every day when the range extender would kick in.
I sold it at 60k miles and had not noticed and drop in range.
I would charge to 100% my second, an i3S, every other day and again taki down to very low charge levels.
I only did about 11k miles in that so again not noticeable change.
Not commuting anymore so my Ionoq 5 gets charged to various levels with no real target.
The exception is only if I need to make a long business or leasure trip, in which case 100%.
I sold it at 60k miles and had not noticed and drop in range.
I would charge to 100% my second, an i3S, every other day and again taki down to very low charge levels.
I only did about 11k miles in that so again not noticeable change.
Not commuting anymore so my Ionoq 5 gets charged to various levels with no real target.
The exception is only if I need to make a long business or leasure trip, in which case 100%.
Edited by so called on Wednesday 12th October 15:03
so called said:
With my first EV, a BMW i3, I charged to 100% for every work day and used it down to 2% every day when the range extender would kick in.
I sold it at 60k miles and had not noticed and drop in range.
I would charge to 100% my second, an i3S, every other day and again taki down to very low charge levels.
I only did about 11k miles in that so again not noticeable change.
Not commuting anymore so my Ionoq 5 gets charged to various levels with no real target.
The exception is only if I need to make a long business or leasure trip, in which case 100%.
But the i3 is one of those with a BMS that doesn’t let you charge above about 80% and go below about 5%. So when it shows 100% charge on the display that is only 80% in reality. I sold it at 60k miles and had not noticed and drop in range.
I would charge to 100% my second, an i3S, every other day and again taki down to very low charge levels.
I only did about 11k miles in that so again not noticeable change.
Not commuting anymore so my Ionoq 5 gets charged to various levels with no real target.
The exception is only if I need to make a long business or leasure trip, in which case 100%.
Edited by so called on Wednesday 12th October 15:03
uknick said:
so called said:
With my first EV, a BMW i3, I charged to 100% for every work day and used it down to 2% every day when the range extender would kick in.
I sold it at 60k miles and had not noticed and drop in range.
I would charge to 100% my second, an i3S, every other day and again taki down to very low charge levels.
I only did about 11k miles in that so again not noticeable change.
Not commuting anymore so my Ionoq 5 gets charged to various levels with no real target.
The exception is only if I need to make a long business or leasure trip, in which case 100%.
But the i3 is one of those with a BMS that doesn’t let you charge above about 80% and go below about 5%. So when it shows 100% charge on the display that is only 80% in reality. I sold it at 60k miles and had not noticed and drop in range.
I would charge to 100% my second, an i3S, every other day and again taki down to very low charge levels.
I only did about 11k miles in that so again not noticeable change.
Not commuting anymore so my Ionoq 5 gets charged to various levels with no real target.
The exception is only if I need to make a long business or leasure trip, in which case 100%.
Edited by so called on Wednesday 12th October 15:03
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