Reminds me of “Chargie”, a gadget that goes inline with your USB charging cable and controlled by an app on the device to limit the charge level to whatever you choose. I think it was born via kickstarter.
“The most Intelligent Battery Health Protection for Phones & Laptops”
https://chargie.org/
+1 for battery university, they're an excellent source. Does anyone have any other suggestions for similarly technically deep (while approachable) articles on any other facet consumer electronics?
My understanding from this article is that:
1. Charge the battery to as low a max percentage as possible (till about 65%)
2. Keep it as cool as possible (up to zero degrees C at least)
3. Use it as little as possible before recharging it (minimize charge-discharge bandwidth)
Aka, over-rate and over size the battery if you're building the device, and minimize extremes on any side of soc (state of charge).
Do EV manufacturers use any other tricks not covered by this?
(Of course, use the device as needed, these are just guidelines for the best perfomance.)
Light bulbs (including LEDs) are similar. If you use them at slightly lower then their maximum rating, things tend to last a LOT longer. The "Dubai lamp" uses this concept - oversized LEDs that are derated, and last a very long time (100k hours). You can do the same by buying oversized dimmable LEDs and simply turning down the brightness.
I don't think this advice is useful. You're going to use your devices, so you won't control the temperature or, largely, the charge percentage.
I think good advice is to keep your devices as cool as you can (ie don't leave your cars in sunlight when there's shade), which you probably did anyway, and keep the battery between 20% and 80% as much as possible. If the battery is going to stay unused for a while, leave it at 3.8V (or close to it), or at 50%.
Batteries are ultimately consumables, so don't stress too much. Just care for them as much as convenient, and that's it.
> I think good advice is to keep your devices as cool as you can (ie don't leave your cars in sunlight when there's shade),
In some climates, such as where I live, the larger issue is the cold in the winter. From what I understand, Li-ion batteries don't like being charged below 0 C. And it is not uncommon for it to dip to -15 C or even -20 C here.
Really, from what I understand, batteries want to be kept above freezing but cool. So yeah, don't leave it in direct sunlight in the middle of summer. The more difficult problem is the winter (unless you happen to have a heated garage).
> You're going to use your devices, so you won't control the temperature or, largely, the charge percentage.
> I think good advice is to keep your devices as cool as you can (...), and keep the battery between 20% and 80% as much as possible.
Yeah that's kinda what I meant. Where it's easy or possible to do so (for eg lots of modern laptops & phones allow charge limits), it's better to follow these guidelines.
> Batteries are ultimately consumables, so don't stress too much. Just care for them as much as convenient, and that's it.
Yeah I agree (and that's what I meant by my last sentence), however, a lot of people (including eg my dad!) end up having battery issues while being unaware that they can do things to protect their hardware.
For example, my phone has enough capacity to last the whole day even at 60% of it's capacity. I've set it to stop charging at 80% (the lowest possible SOC) for this reason. On my laptop, I frequently reduce it to 60% as I use it plugged in.
> I don't think this advice is useful.
I'm afraid I don't get what's not helpful? We're probably talking across each other.
It came across to me as "keep your batteries always under 0 C", which obviously almost nobody can do, and it leads to a sense of "eh, I won't go to these lengths, might as well do nothing", which is counterproductive.
I see the same reaction with healthy eating, where people are so put off by extremely militant advice that they think "I can't eat only vegetables all day, fuck it, I'll eat these three cheeseburgers".
I agree with your second comment, the first one just could be misconstrued as very hard-to-follow advice.
That's backwards. At too low temperatures batteries start to take damage during discharge or (especially) charge, so 0C is the lowest temperature at which you should charge it. 5C would be better.
It's a concern mainly for e.g. offgrid batteries being used in the winter.
> Do EV manufacturers use any other tricks not covered by this?
Automotive EE here. EV aren’t ready for world wide use. That statement is constantly ignored by people in California who see zero issues with their new expensive fancy cars.
Shortest version… The heating and cooling systems of the battery are there to prevent damage. BUT… who powers the heating and cooling systems? The battery of course.
In a traditional or better yet a plugin hybrid, you can use the gas engine to control how much electric you are using in conditions that would be harmful to the battery. In EV vehicles you have no choice. The car won’t tell you “you can’t drive right now”.
The marketing of EVs was a mistake, and every mfg is paying for it. Ford taking a 2 billion write off this year on their EV line and canceling a lot of their vehicles.
They will be cool, but this generation makes a great second vehicle or town vehicle. Absolutely not an extreme weather highway vehicle.
...what? You leave your car plugged in, and that's it. Then the BMS will take care of the battery without having to use it's energy.
If I preheat the car it also preheats the battery. If it's not warm enough it won't allow full recuperation. Oh my god, I have to use THE BRAKES for a few minutes, literal trash car.
And all those people in Norway, you know, with their heat pumps and EVs. Obviously life just grinds to a halt there every winter. *dramatic eye roll
driving an ev for the past 2.5 years with 97% SOH remaining. So I must be doing something right wrt treating the battery nicely. And I don't have a garage, it's outside most of the time. I drove thousands of km in subzero C temperature.
>Cool. And when you need to drive it? Most systems do not keep the battery heater running indefinitely.
I get in and put it into drive. When it's cold, I preheat it, I can program departure times, so the battery is conditioned and the cabin warmed in advance. Even at sub-zero temperatures, it always starts reliably, unlike a diesel engine, which, as you know, requires preheating and can struggle with extreme cold starts. Also requires winter diesel.
When I need to drive me EV I open the door, get in, close the door, put it in drive and drive off.
Were you expecting something different? I'm in Norway by the way where it is expected to be -15 C in a few days; after eight years of EV driving (2015 Tesla S 70D) I am not anticipating any problems.
> What is your experience?
I've told you mine, what's yours? Or will you argue from authority again?
Fully agree (I'm 100% team PHEV or EREV/REEV) as a mechanical engineer. IMO BEVs and PHEVs/REEVs should be on parity in terms of tax/govt incentives, while encouraging electric use - for eg, subsidized (PH)EV charging, high(er) costs in city centres if running in ICE mode, etc.
I was just curious if EV manufacturers use any other tricks that're "well known" in EV-land but not for the average consumer.
These acronyms are a nightmare, what the hell is a PHEV? EREV? PZEV?
Consumers are just expected to know this stuff somehow, it’s nuts. Sometimes I buy parts for my car and just hope I selected the right one, because some models are PZEV/not PZEV but the sticker that would tell me has turned completely white & can’t be read.
Consumers just take their shit to the dealer which hires technicians who job it is, literally, to know "what the hell". If that is too complicated for you to figure out, I can't recommend you do your own work on your car.
I have a vehicle in my personal shop right now. It needs a new battery, it is effectively totaled.
The battery costs more than the vehicle.
The effort for me to replace the battery modules (not even the cells inside of them) involves taking the entire suspension out, and then, you have the ACTUALLY FATAL issue of working on the battery pack. You need 1000V+ gloves that expire every six months, composite ratchets and sockets, and for me high voltage certification.
There is nothing on an ICE vehicle that can kill you while working on its parts.
I will be downvoted by people who need (literally) to defend their purchase. Always am on this topic.
After the first battery of my Samsung S4 expanded at the end of its life in less than 2 years, I found a utility that didn't work perfectly but could limit charge anywhere between 30 to 100% most of the time, and it prolonged the lifetime of the couple of later batteries during the 10+ years I used the phone with a limit around 66%.
I was glad to see my new Samsung XCover 7 has a built-in option to limit charge to 80%, although a flaky usb cable could sometimes overcharge to 100%. And also has a removable battery.
It's probably not a flaky USB cable. Androids charging limit of 80% includes a policy to charge 100% every 14 days to recalibrate the battery controller.
A possibility to limit charging to ~65% does not exist per se but you can measure the time it takes to charge from 25% to 65% and use a power timer to shut down charging after that period of time. It's not accurate but easy to implement.
Another factor is fast charging... The battery loses capscity significantly faster if you fast charge often...
Maybe I just expect too much battery life, but I find that I get quite low or even run out when I limit charging to 80%.
My feeling is that the coulomb counting on the Pixel 8 Pro is just not very accurate, so the phone thinks it's at 80%, but is really at 60% or 40%.
I still use the feature, but now I have to top up during the day every so often. I suppose rationally I should just charge to 100% rather than take a medicine that causes the same side effect as the disease its meant to treat, but I'm not that rational.
> although a flaky usb cable could sometimes overcharge
The charge controller is in the phone. The cable and power supply have no bearing on when charging is terminated. Android has an "optimized charging" option where it will charge above 80% shortly before it predicts you are likely to unplug. Samsung may have meddled with this behavior but that isn't Android's fault.
I definitely would do that if I could. I would absolutely love to tell it to only charge to 66% (or whatever, even 50% would work). I rarely use the phone for multiple hours at a time without access to power, and when I do, I usually know beforehand (like during a trip or something) so I could tell it to charge all the way. My battery rarely goes below 80%, even now that the phone is 3.5 years old.
I understand newer iphones now have the option to only charge up to a certain percentage. Mine doesn't have that, it only has the "smart charging", which tries not to charge it too quickly and only is full by the time it expects you'll use it (usually in the morning). It's very hit and miss for my use patterns, so it ends up at 100% most of the time...
But yeah, at some point we should also consider the tradeoff between convenience and battery life. Batteries can be replaced, having to charge twice a day is a PITA for me.
My charging solution is that I've purchased three (cheap and therefore slow) wireless charging docks that sit my phone slightly leaning backwards, therefore nicely viewable if necessary.
One sits on my desk at work, one sits on my desk at home and the third sits on my bedside table (it acts like a clock radio / alarm clock). I just place it on the relevant charger while working / sleeping and it's always got enough charge when I need it.
(I also use the surprisingly fairly recent addition of charging protection to limit it to 80% charge)
I'm aware this won't work for all use cases, but it's great for mine.
They’re a joke, I used to have one in my car and the combination of sunlight & internally produced heat would make my phone shut off & display a “iPhone is too hot” message. Even when it’s cold outside.
My understanding from this article is that:
1. Charge the battery to as low a max percentage as possible (till about 65%) 2. Keep it as cool as possible (up to zero degrees C at least) 3. Use it as little as possible before recharging it (minimize charge-discharge bandwidth)
Aka, over-rate and over size the battery if you're building the device, and minimize extremes on any side of soc (state of charge).
Do EV manufacturers use any other tricks not covered by this?
(Of course, use the device as needed, these are just guidelines for the best perfomance.)
I think good advice is to keep your devices as cool as you can (ie don't leave your cars in sunlight when there's shade), which you probably did anyway, and keep the battery between 20% and 80% as much as possible. If the battery is going to stay unused for a while, leave it at 3.8V (or close to it), or at 50%.
Batteries are ultimately consumables, so don't stress too much. Just care for them as much as convenient, and that's it.
In some climates, such as where I live, the larger issue is the cold in the winter. From what I understand, Li-ion batteries don't like being charged below 0 C. And it is not uncommon for it to dip to -15 C or even -20 C here.
Really, from what I understand, batteries want to be kept above freezing but cool. So yeah, don't leave it in direct sunlight in the middle of summer. The more difficult problem is the winter (unless you happen to have a heated garage).
> I think good advice is to keep your devices as cool as you can (...), and keep the battery between 20% and 80% as much as possible.
Yeah that's kinda what I meant. Where it's easy or possible to do so (for eg lots of modern laptops & phones allow charge limits), it's better to follow these guidelines.
> Batteries are ultimately consumables, so don't stress too much. Just care for them as much as convenient, and that's it.
Yeah I agree (and that's what I meant by my last sentence), however, a lot of people (including eg my dad!) end up having battery issues while being unaware that they can do things to protect their hardware.
For example, my phone has enough capacity to last the whole day even at 60% of it's capacity. I've set it to stop charging at 80% (the lowest possible SOC) for this reason. On my laptop, I frequently reduce it to 60% as I use it plugged in.
> I don't think this advice is useful.
I'm afraid I don't get what's not helpful? We're probably talking across each other.
I see the same reaction with healthy eating, where people are so put off by extremely militant advice that they think "I can't eat only vegetables all day, fuck it, I'll eat these three cheeseburgers".
I agree with your second comment, the first one just could be misconstrued as very hard-to-follow advice.
It's a concern mainly for e.g. offgrid batteries being used in the winter.
Automotive EE here. EV aren’t ready for world wide use. That statement is constantly ignored by people in California who see zero issues with their new expensive fancy cars.
Shortest version… The heating and cooling systems of the battery are there to prevent damage. BUT… who powers the heating and cooling systems? The battery of course.
In a traditional or better yet a plugin hybrid, you can use the gas engine to control how much electric you are using in conditions that would be harmful to the battery. In EV vehicles you have no choice. The car won’t tell you “you can’t drive right now”.
The marketing of EVs was a mistake, and every mfg is paying for it. Ford taking a 2 billion write off this year on their EV line and canceling a lot of their vehicles.
They will be cool, but this generation makes a great second vehicle or town vehicle. Absolutely not an extreme weather highway vehicle.
If I preheat the car it also preheats the battery. If it's not warm enough it won't allow full recuperation. Oh my god, I have to use THE BRAKES for a few minutes, literal trash car.
And all those people in Norway, you know, with their heat pumps and EVs. Obviously life just grinds to a halt there every winter. *dramatic eye roll
No one is talking about the brakes.
I’m an automotive engineer that has worked for two of the big4. What is your experience?
>Cool. And when you need to drive it? Most systems do not keep the battery heater running indefinitely.
I get in and put it into drive. When it's cold, I preheat it, I can program departure times, so the battery is conditioned and the cabin warmed in advance. Even at sub-zero temperatures, it always starts reliably, unlike a diesel engine, which, as you know, requires preheating and can struggle with extreme cold starts. Also requires winter diesel.
When I need to drive me EV I open the door, get in, close the door, put it in drive and drive off.
Were you expecting something different? I'm in Norway by the way where it is expected to be -15 C in a few days; after eight years of EV driving (2015 Tesla S 70D) I am not anticipating any problems.
> What is your experience?
I've told you mine, what's yours? Or will you argue from authority again?
Fully agree (I'm 100% team PHEV or EREV/REEV) as a mechanical engineer. IMO BEVs and PHEVs/REEVs should be on parity in terms of tax/govt incentives, while encouraging electric use - for eg, subsidized (PH)EV charging, high(er) costs in city centres if running in ICE mode, etc.
I was just curious if EV manufacturers use any other tricks that're "well known" in EV-land but not for the average consumer.
I have a vehicle in my personal shop right now. It needs a new battery, it is effectively totaled.
The battery costs more than the vehicle.
The effort for me to replace the battery modules (not even the cells inside of them) involves taking the entire suspension out, and then, you have the ACTUALLY FATAL issue of working on the battery pack. You need 1000V+ gloves that expire every six months, composite ratchets and sockets, and for me high voltage certification.
There is nothing on an ICE vehicle that can kill you while working on its parts.
I will be downvoted by people who need (literally) to defend their purchase. Always am on this topic.
Don' let the voltage go to far below 3.7V and don't over charge above ~4-4.2V.
I was glad to see my new Samsung XCover 7 has a built-in option to limit charge to 80%, although a flaky usb cable could sometimes overcharge to 100%. And also has a removable battery.
A possibility to limit charging to ~65% does not exist per se but you can measure the time it takes to charge from 25% to 65% and use a power timer to shut down charging after that period of time. It's not accurate but easy to implement.
Another factor is fast charging... The battery loses capscity significantly faster if you fast charge often...
I personally only use the 80% limitation...
My feeling is that the coulomb counting on the Pixel 8 Pro is just not very accurate, so the phone thinks it's at 80%, but is really at 60% or 40%.
I still use the feature, but now I have to top up during the day every so often. I suppose rationally I should just charge to 100% rather than take a medicine that causes the same side effect as the disease its meant to treat, but I'm not that rational.
95% would probably work out for you and still decrease battery wearout...
The charge controller is in the phone. The cable and power supply have no bearing on when charging is terminated. Android has an "optimized charging" option where it will charge above 80% shortly before it predicts you are likely to unplug. Samsung may have meddled with this behavior but that isn't Android's fault.
I understand newer iphones now have the option to only charge up to a certain percentage. Mine doesn't have that, it only has the "smart charging", which tries not to charge it too quickly and only is full by the time it expects you'll use it (usually in the morning). It's very hit and miss for my use patterns, so it ends up at 100% most of the time...
But yeah, at some point we should also consider the tradeoff between convenience and battery life. Batteries can be replaced, having to charge twice a day is a PITA for me.
One sits on my desk at work, one sits on my desk at home and the third sits on my bedside table (it acts like a clock radio / alarm clock). I just place it on the relevant charger while working / sleeping and it's always got enough charge when I need it.
(I also use the surprisingly fairly recent addition of charging protection to limit it to 80% charge)
I'm aware this won't work for all use cases, but it's great for mine.