Battery degradation is the gradual loss of a battery’s ability to store energy and deliver power. In lithium-ion packs, factors like heat and spending long periods at very high state of charge can speed up this wear.
LFP is a type of lithium battery used in some EVs. It usually costs less and is considered safer, but it may not store as much energy per unit size as some other battery types.
A charge cycle is basically one full round of charging and then draining the battery. Some battery types can handle more of these rounds before their performance drops.
Power density is how much “usable output” you can get from a battery for its size. If a battery has lower power density, it may not go as far in practice for the same battery size.
The Tesla Model Y is an all-electric SUV made by Tesla. It uses a battery pack, and some versions use an LFP battery type, which can change how the car charges and how the battery is protected. That’s why it may be mentioned when people talk about battery differences in EVs.
The Tesla Model 3 can come with different battery types depending on the version. This matters because the battery chemistry can change how far the car can go and how much it costs.
The Volvo EX30 comes in different versions, and this can mean different battery types. Here, the single-motor version is described as using LFP, while the dual-motor version uses NMC.
Car
BYD
BYD is an EV brand that (according to this segment) tends to use LFP batteries across many of its cars. They also describe BYD’s Blade battery as being made with LFP chemistry.
ebedatabase.org is referenced as a resource for looking up EV battery details by vehicle. The segment describes using it to find battery entries like nominal capacity, voltage architecture, and cathode material.
Nominal capacity is the battery’s rated size, usually measured in kWh. It’s the official number the manufacturer uses, and it can include some extra “buffer” energy that isn’t fully usable.
EVs can be built around different electrical voltage levels, like 400V or 800V. The higher-voltage setups can often charge faster because they move power more efficiently.
The cathode is the part of the battery that helps determine what “type” of battery it is. Knowing the cathode material tells you whether it’s an LFP-type battery or an NMC-type battery.
State of health is basically how good the battery is compared to brand-new. If you treat it harshly (like sitting at very high charge for long periods), it can slowly lose capacity over time.
The Dodge Charger is a car designed for strong performance, and it’s often used for both daily driving and longer trips. The charging mention in the podcast is about how long it can take to add energy to a battery, especially when you’re trying to go from 80% to 100%. The point is that the last part of charging can take longer than earlier charging.
WLTP range is a standardized “how far it should go” number from a test. As the battery degrades, the real usable range can shrink compared to that original test estimate.
Battery health results are test measurements that tell how much life is left in an EV battery. They help show whether batteries are degrading faster or slower than people think.
A battery cycle is basically how many times you use up the battery’s stored energy and put it back. Even if you don’t go all the way up and down every time, repeated partial use can still count as a full cycle. Using the battery more often usually wears it down faster.
Kilowatts (kW) are a measure of how fast your EV charges. More kW usually means faster charging. Faster charging can be harder on the battery, especially if it happens a lot and the weather is very hot.
Term
NFC batteries
NFC is being used to mean a specific type of EV battery chemistry. Different chemistries can handle charging and heat differently, so knowing which one you have helps you decide how often and how full to charge. The episode is basically saying: chemistry affects battery care.
LFP is a type of EV battery chemistry. It’s generally better at handling repeated charging without wearing out as quickly as some other battery types. That’s why the host suggests charging it more confidently if you have LFP.
evdatabase.org is a website the host recommends for figuring out what battery type your specific EV uses. It’s suggested as a backup when a dealer can’t answer. Knowing the battery type helps you choose safer charging habits.
State of charge is basically how full the battery is, like a fuel gauge for electricity. Higher SoC means the battery has more energy available, but it can also change how the car drives and charges.
An 800V architecture means the EV’s electrical system is designed around a higher voltage than the more common 400V setup. Higher system voltage can enable higher charging power and faster charging speeds, especially with compatible chargers.
400V refers to a lower-voltage EV electrical system compared with 800V. While the battery chemistry can be the same, the car may be limited in how quickly it can accept charge power.
Regen braking is when the car slows down and turns some of that energy back into electricity to recharge the battery. If the battery is full, the car can’t store much extra energy, so regen may not work as strongly.
One pedal driving means you can slow the car mostly by lifting off the accelerator. If the battery is full, the car may not be able to recharge enough energy during slowing, so it won’t slow as strongly.
A battery health check is a way to find out how healthy the EV battery is. For a used EV, it can help you understand whether the battery has degraded a lot or is still in good shape.
LIVE
Hi, I'm Gary and this is Evie Musings, a podcast about renewables, electric vehicles and things
that are interesting to electric vehicle owners. On the show today, we'll be looking at how much
you should charge your EV and when.
Last May, I took my iPhone to the local Apple store and they ran a diagnostic and told me that
the battery in there was currently at 78% state of health and that meant that when the display
told me it was at 100, it was actually only at 78% of the full battery capacity. As a result,
my phone needed charging more often, didn't last as long on a charge and was, not to break
too finely, a pain in the arse or asked to those listening across the pond. They replaced the
battery with a brand new one and I went happily away. Actually I didn't, there was a timing
misunderstanding and I got managers involved etc but that's not the point of this story,
that's me about it if you ever meet me in person and want the full down low on it.
Now we're now 12 months later and I've just checked my iPhone and the battery is now at 91%
state of health so it's already degrading. Now we've all got phones now, the universal
thing about phones is that it doesn't matter how long you have them or how you charge them,
sooner or later you'll look into the settings and you'll find your battery is at 80% state of
health or lower. I suppose that's why many people opt out up for a new phone every year when in
reality a new battery is all that's needed. So why is degradation so bad on phones? Well
there are many reasons for that and we've gone through them in other episodes and primarily
it's the fact that phones don't have complex battery management and heat management systems
but outside of that there are other reasons why your phone battery degrades quickly and most of
it is to do with how and when you charge it. The EV Musings podcast is sponsored by Zatmap,
the go-to app for EV drivers helping you find and pay for public charging with confidence.
Now we get to that confession part of the podcast, admit it, how many of you
plug your phone in at night on the bedside table and let it charge while you're asleep?
I see you in the back looking slightly sheepish, come on admit it, of course you do, it just
makes sense right? You're not using it overnight so why not let it charge? Well unfortunately
you're actually damaging your battery especially if you're one of a number of people
who leave the phone in the bed with you under the covers while charging. Pretty much every domestic
battery powered appliance, phones, vapes, laptops, toothbrushes is powered by an NMC,
nickel, manganese, co-op or battery. The enemy of NMC batteries is heat, they don't like to be too
hot, they don't like to get too hot when they're charging. Sidebar, actually they don't mind heat
when they're charging as long as it's dissipated immediately after charging is finished. Battery
electrochemist Dr. Ewan McTurk told us that when he came in a while back to talk batteries.
So plugging in, putting it under the covers and letting it charge all night is damaging your phone
battery. Even leaving it on the bedside table overnight to charge is bad because your phone is
charging to its maximum capacity and staying plugged in. If you've got a phone like mine it takes
about an hour, an hour and a half to charge so if it's left plugged in for seven or eight hours
that's not good. So where am I going with this? There are lots of people who will listen to this
and they'll think there's no way I'm getting electric car if the batteries degrade like they do
in my phone. Well obviously they're not going to degrade that quickly and we've recently done an
episode with Avalu where they showed us just exactly what sort of degradation you can expect
on your EVs battery. The TLDR on that is the battery is probably going to last longer than the car
it's in but most people will charge their EVs overnight as they're sleeping and you can see
how the parallels with leaving the iPhone plugged in on the bedside table or even worse under the
covers with you will cause people to think that EV batteries will have the same degradation problems
but the other factor that plays into a battery life alongside heat is how much and how often you
charge it. So today we're going to take a quick look at when you should and shouldn't charge your
battery up to a high state of charge and before we start we need to make sure that we're talking
about the same things and define our terms. When we talk about phone batteries we're usually talking
about NMC batteries these are the little lithium iron batteries which have as I've said nickel
manganese and cobalt in them. These are the typical batteries found in most consumer goods your phone
your toothbrush vapes laptops rechargeable drills anything. So they're also used a lot in electric
vehicles but they're not the only battery chemistry that's used and the other main chemistry is called
lithium iron phosphate or LFP. There's no cobalt in these and very little magnesium it's cheaper
and easier battery to manufacture as Ewan McTurk said on the show it's basically some lithium rust
and a bit of fertilizer. So why does some cars have NMC and others have LFP? Well there are pros
and cons to each chemistry LFP is better for charge cycles it handles heat better it's less likely to
combust if pierced and it's cheaper but it doesn't have as high a power density which means that it
won't go as far for a given battery size 80 kilowatt hours of NMC batteries will have a longer
range than 80 kilowatt hours of LFP batteries but it will cost more. Many manufacturers have
installed LFP batteries in their bottom of the range cars and this makes them cheaper
but reduces their range and that's why cars such as the 60 kilowatt hour Tesla Model 3 standard range
rear wheel drive have an LFP battery but the more expensive and longer range Model 3 performs with a
79 kilowatt hour battery uses NMC. It's the same for the Volvo EX30 single motor which has a 49 kilowatt
hour LFP battery for the 65 kilowatt hour dual motor of NMC batteries. If however you're driving
around in a BYD chances are you've got an LFP battery regardless of the cost of the car or the
size of the battery. They've painted a battery design called BYD Blade which is 100% LFP and I'm
pretty much sure all BYD cars use this. So how do you tell which chemistry you actually have in your
EV? It's all well and good me talking about how you need to treat different battery chemistries
differently but if you don't know how to find this information I might as well be talking Greek.
Apologies to anyone watching or listening who is Greek. Luckily there's a really easy
way to find out. You go to the ebedatabase.org and search for your car. Click into the entry of
that car, scroll down to the part label battery and you'll see things like nominal capacity that's
the full size of the battery including the buffer at the top of the bottom, the architecture whether
it's 400 or 800 volt architecture and the cathode material. That's what you're looking
for. If it says LFP that's the better but less powerful chemistry. If it says NMC that's the
original more powerful chemistry. This is important because each of these chemistries
needs to be treated differently to get the best out of it and preserve battery state of health
for longer. So what are the differences? You'll have heard me say numerous times on this show to
not charge your battery above 80% state of charge unless you plan to take a long drive.
The reason for this is that once you start to approach the maximum capacity for a battery
it has some adverse effects on the health. It's a little like filling a balloon up until it's
ready to burst. It's high in the short term, push it a little too far and well you know what
happens next. This applies to NMC batteries only though. If your car is one that has the LFP batteries
this doesn't apply. You can quite happily charge them up to 100% day in and day out
with no adverse effects. In fact there is a school of thought that says that you should
probably keep your LFP battery at 90% or higher as often as possible. But I don't want to make
this quite clear. What I'm not saying is that you can't let LFP go below 90% state of charge
and you can't let NMC go over 80% state of charge. That's absolutely not what I'm saying.
You can quite happily charge an NMC battery up to 100%. All you need to remember is that you
should really only do this if you're not going to let the car stand at 100% for a long time.
The typical example is when you're going on a long journey. I might go to my parents' friend
instance. I usually have the car at 80% state of charge until the night before I leave. I then
charge it to 100% overnight, set off the next morning. As the charge has only been 100% for
short period of time there's no issue. If I'm stopping to charge en route I'll generally only
send it up to 80%. Not because it's harmful to the battery but because it's quicker to charge to
80% move on and stop further on the road if you need more charge than it is to stay on a charger
from 80% to 100%. This applies regardless of the battery chemistry you're using. So what effect
does degradation have on your battery? Well at a basic level as you would imagine it reduces the
effective range of your vehicle. If your original WLTP range is 200 miles and your battery degrades
by 5% you're going to lose 10 miles in the maximum range. If it degrades by 20% you're going to lose
40 miles from your range. In winter the range loss is going to be higher because the cold weather
will reduce the maximum range anyway and we talked all about this in the cold weather episode number
292. The impression that many non EV drivers have about degradation is that it matches that of a phone
and your battery will be dead within three years often resulting in it being thrown into landfill
apparently and that gives rise to what I call troding as battery. It's both too expensive to
replace but cheap enough to throw into landfill. Of course neither of these things are actually
accurate. There have been many studies done on battery degradation and almost without exception
it's nowhere near as bad as people imagine. In fact if you cast your mind back to the episode we did
towards the start of this season with Dr Marcus Berger from Avalute Battery Diagnostics you remember
that he showed a graphic of all the battery health results that they've got from the tests
they've done over the years and two things stood out to me from those graphics. First the difference
in degradation between full battery electric vehicles and plug-in hybrid vehicles and second
a relatively low amount of degradation that occurs as vehicle mileage increases. Yes there are
outliers the graph showed a couple of relatively low mileage vehicles with high battery wear.
This could be due to a multiple and multitude of reasons but the most likely is a faulty
cell in a pack but it also showed lots of high mileage vehicles with relatively low degradation
proving again that the battery health is much better than the naysayers would have you believe.
So looping back to the beginning of this discussion what's the best way to minimize
battery degradation? Reduce heat, reduce cycle. The first one is making sure that your battery
does not get unduly hot. It usually occurs through rapid charging although to repeat what you and
told us heats only a problem if it isn't dissipated quickly. The new BYD 1500 kilowatt charges
and associated batteries prove that that's the case. So how do you reduce heat? Well minimize
ultra rapid charging, minimize high power loads on the battery, keep the vehicle out of direct
sunlight or at least extreme sunlight. A typical hot sunny day in the UK probably isn't going to
be an issue but 100 days of 100 degrees Fahrenheit in Phoenix, Arizona may well be.
Secondly, reduce cycling. Now this is more difficult. A cycle is when a battery is charged
and discharged 100%. This doesn't mean it's charged to 100% then discharged to 100%. It means
that 100% of the battery capacity has been put in and 100% has been taken out. So if you charge to
100, run it down to 50, then charge it up to 100%. That's half a cycle. If you do that twice,
that's a full cycle. The more cycles a battery goes through, the more degradation will occur.
Obviously, the more you use the vehicle, the more the battery will cycle. The more it cycles,
the more it degrades. But not in isolation. A vehicle that's charged slowly and regularly
in cool conditions rather than heat can have a lower degradation than the same vehicle that's
done the same mileage but has been rapidly charged often and lives in a high heat environment. So
it's complicated. I think it's worth saying at the moment that this is a minor issue in the big
scheme of things. If you live in a really hot country and rapidly charge your EV at high kilowatt
values multiple times a day, then you might need to look at what that's doing to your battery
degradation. But if you're not in that situation and I suspect the vast majority of us are not in
that situation, then you're probably not going to have as much of a problem with your battery
if you have any problem at all. As we come to the end of this episode, I want to summarize this
situation and differences between NFC and LFP batteries. When you get your new or second hand
EV, it's often best if you know the battery chemistry. Try asking the salesman and see if
they know. It's a good chance they don't. My experience asking that question has about
a 10% hit rate. If they do know it, great. If they don't, go to plan B as we mentioned earlier.
Hit the evdatabase.org, look up your make and model and see what that says about the battery
chemistry. Make sure you get the right make and model and the right battery size. As mentioned
earlier, often the smaller battery size in a vehicle ranges LFP and the larger can be NFC.
Once you know what battery chemistry you've got, you're in a great position to be able to understand
how much you can charge your car on a daily basis. If it's LFP, go ahead and charge that puppy up
to 100% every night. No issue there. Hit the NMC and set that figure to 80%. It's a more modern car
that'll be a setting in the vehicle somewhere to define the maximum state of charge. In older
vehicles, you might have to rely on working out the time of charge to click off automatically
on overnight charging. In other words, if you have a 50kWh NFC battery that's a 10% state of charge,
you're going to want to add 70% or 35kWh to get it up to 80%. With a charge that averages 7kW,
you'll need to charge it overnight for five hours. You can set this either in the vehicle,
in the cars app, if it has one, or in the charger app. Once you've done that,
just ignore things and live your life. There are a couple of ancillary things that we need to note.
Some cars have 800V architectures, so they can take very high charge speeds.
Some only have 400V. This makes no difference to the battery. Both NFC and LFP can deal with that
the same. Now throughout this episode, I've referred to stated figures such as 80% and 100%.
These should be considered normal figures, but not hard and fast figures.
If you want to charge your NFC battery to 70% or 85%, feel free to do that,
especially on an occasional basis. Likewise, if you want to leave your LFP battery at 90%,
not 80%, not 100% from time to time, that's also fine. Just don't make a habit of doing that.
The other thing to remember with a battery at 100% regardless of whether it's NFC or LFP is,
if you're driving at 100% state of charge, you find the regen braking or one pedal driving
doesn't work quite as well. And that's because both of these feed energy back into the battery,
and if the battery is full, there's no way for that energy to go.
And discounted charging across thousands of charge points.
So what are your thoughts on battery degradation? Does it worry you?
Is a sort of battery dag in a second hand EV putting you off buying one? If it is,
you really shouldn't get yourself a battery health check, as we just discussed in episode 285,
and help put that worry to rest in your mind. Remember, second hand EVs have much,
much better state of health than many people thought they were going to have a few years ago.
A discussion with Marcus Berger from Avalu proved that. Now, if this has been useful to you,
don't forget to like, comment, and subscribe, please. I hope you enjoyed listening to today's show.
If you have any thoughts, comments, criticisms, or other general messages,
to pass on to me, I can be reached at info at evmusings.com. And on the socials,
I'm on BlueSky at evmusings.bsky.social. I'm also on Instagram at evmusings,
where I post short videos and podcast extracts regularly. So why not follow me there?
Thanks to everyone who supports me through Patreon on the monthly basis,
and through coffee.com on an ad hoc one. If you enjoyed this episode, why not buy me a coffee?
Go to coffee.com slash evmusings, and you can do just that.
Regular listeners will know about my two ebooks. So you've got an electric,
and so you've got a renewable. First one of those has had a recent update.
You'll see it with a bright red image on the front, just like I'm showing on the screen here.
Both of those are at 99p each, or equivalent, and you can get them on the Amazon Kindle Store.
Check out the links in the show notes for more information,
as well as a link to my regular evmusings newsletter and associated article.
Now I know you're probably driving, or walking, or jogging, or in the shower,
or washing the car, but if you can remember and you enjoyed this episode,
proper review in iTunes, please. Really helps me out. I did go out and go in and have a look
recently at some of the most recent reviews. Thank you very much for those who took time
to do that for me. If you've reached this part of the podcast and are still listening, thank you.
Why not let me know you've got to this point by messaging me
at musingseve.bestightedsocial with the words slow and steady, hashtag if you know you know,
nothing else. Thanks as always to my co-founder Simon.
He's an expert battery charger. Thanks for listening. Bye-bye now.
About this episode
Battery degradation isn’t as scary as it sounds, and charging habits play a big role. The hosts start with a phone example—an iPhone battery at “78% state of health”—to explain how “100%” can mean less usable capacity. They break down why heat and high state of charge accelerate wear, especially for NMC, while LFP is more tolerant. Practical guidance includes limiting charge (often “above 80%” for NMC), reducing heat and full cycles, and using evdatabase.org to identify your car’s battery details.
I wanted to revisit something that comes up again and again with EV drivers and people thinking about going electric. Battery degradation.
In this episode, I break down what’s really going on, using a simple comparison we all understand: our phones. From how we charge to when we charge, I explore what actually impacts battery health and what really matters when it comes to keeping your EV running well long term.
What You’ll Discover
- Why EV Batteries Aren’t Like Your Phone: Despite common fears, EV batteries degrade far slower and often outlast the car itself.
- The 80 Percent Rule Explained: For NMC batteries, limiting daily charging to around 80 percent can help preserve long-term battery health.
- How Charging Habits Really Matter: Heat, rapid charging, and frequent full cycles all play a role, but most drivers won’t see major issues in everyday use.
What really stands out to me is how much of the concern around EV batteries is driven by misunderstanding. We’ve all experienced phone batteries degrading quickly, so it’s easy to assume the same thing will happen with a car. But the reality is very different. EVs have far more advanced battery management systems, and the data shows degradation is much lower than people expect.
There’s also a useful mindset shift here. It’s not about obsessing over perfect charging behaviour. It’s about understanding the basics and then getting on with your life. Whether that’s charging overnight, using rapid chargers when needed, or simply knowing your battery type and adjusting slightly.
If you’ve been worried about battery life or know someone who is still on the fence about EVs because of it, this episode is worth sharing. It cuts through the noise and gives you a clear, practical way to think about it.
The EV Musings Podcast is sponsored by Zapmap, the go-to app for EV drivers, helping you find and pay for public charging with confidence.
The EV Musings Podcast is sponsored by Zapmap, the go-to app for EV drivers, helping you find and pay for public charging with confidence. Zapmap is free to download and use, with subscription plans for enhanced features such as using Zapmap in-car on CarPlay or Android Auto, and discounted charging across thousands of charge points.
Download the app from the Apple App Store or Google Play Store or find out more at www.zapmap.com.
