How to prolong lithium based batteries | Hacker News Reader

How to prolong lithium based batteries

batteryuniversity.com

144 pointsVHRanger111 comments

I have had my phone for 4.5 years. I charge it every night to 80% - I have Accubattery installed, so it pings to tell me to unplug it, and it also does a fairly decent job of measuring the capacity. I charge on a fast charger (10W) instead of the super-fast charger (18W) because that keeps the temperature from rising too much. I use the phone a fair amount, so I'm usually charging from around 50%. Therefore, the battery has had ~1600 cycles of around 30%, or 480 full cycles equivalent. The design capacity of the battery is 4000mAh, and Accubattery tells me it currently stores 3460mAh, which is 87% of the design capacity.

I therefore approve and recommend the above strategy for treating the battery to make it last longer. I also recommend Accubattery - it seems to do the job fairly well.

Accubattery pings, but doesn't actually stop charging. Some Android, Samsung Galaxy for instance, now has "battery protection" mode that stops charging at 80%.

I just use the hell out of my phone battery and pay 50 bucks every 3 years to replace it.

Me too except my first phone is the only one where I had to replace the battery. My 5 year old phone still lasts the whole day without going through any of this rigmarole. It's mostly superstition and the parts that aren't are such a wash that they aren't worth worrying about. Just look at these people trying to reach an agreement on whether you should stop charging at 80% or not. Your gadgets should work for you not the other way around.

On Android, I use the "Advanced Charging Controller" module for Magisk.

If you have some way of rooting your phone and installing Magisk:

https://magiskmanager.com/

Then you can download the ACC module and set it to halt charging at 80%:

https://github.com/VR-25/acc

This functionality should be native to Android and iOS. Yesterday.

It is with the latest iOS

If you charge overnight, newer Androids (12+?) will charge to 80% then trickle-charge to 100% over a few hours before your next alarm. This purportedly gets most of the benefit of lower charge thresholds, presumably because charging that last 20% quickly accelerates wear.

I have a smart plug configured to power plugged into it charger for 40min or so during the night. It takes it to ~80-85% and it's automatic.

> I have Accubattery installed, so it pings to tell me to unplug it, …

Just as a PSA, you can create an Automation in the built-in Shortcuts App to do something similar.

(Show Notification / Speak Text on Battery Level below 20% / above 80% - enable Automation, and turn off Ask Before Running and Notify When Run)

Accubattery is an android app, so that wouldnt help much.

I’m not a battery expert but some coworkers from the battery lab at work are, and they say that charging more often is better than doing big cycles. On most chemistries.

In more concrete terms, it’s better to keep the state of charge between for example 60 to 30% compared to for example 80% to 15%. Big cycles like 100% to 5% are the most damaging over time.

Do you know if it is true that a battery reporting 100% is really only 80% and 0% is really about 20%? I heard that somewhere, but have had trouble confirming it. At least for something like a common smartphone.

Probably depends on the device,but I bet that marketing incentives suggest most won't. I mean do you buy the device that says10 hours battery live or 8 hours battery life?

"The battery is messed up after 2 years" is a complaint I've seen and it was pretty damaging to my buying intentions. Just one data point

I think it's hard to define "the true 100%". It's always a matter of finding a tradeoff between capacity and lifespan – by defining a voltage range.

True 100% seems easy for LiPo; it's the point at which it spontaneously catches fire.

“Spontaneously” seems to imply that it’s not actually a deterministic point.

It depends on the BMS. Some have big buffers, some don’t. One simple clue is how fast it charges relative to the state of charge. If the battery takes a while to go from 95 to 100%, it more likely goes to a full state of charge. If the battery charges very fast to 100%, it probably has some buffer.

In my experience, vacuum cleaners and smartphones are designed to destroy the battery as fast as possible, while most car manufacturers will have a big buffer and lie about the true 100%. With some notable exceptions though, like Tesla that allows to charge to 100% with some scary warnings or Nissan that designed some early Leafs battery pack without longevity in mind.

This % all depends on how the battery management system (BMS) was designed to manage the state of charge (SOC). Some BMS may set 100% SOC to 80% capacity to prolong the cell and pack lifetime. Additionally, 0% SOC may be set as high as 20% capacity.

>> Additionally, 0% SOC may be set as high as 20% capacity. <<

I think that was the case for GM Bolt years ago, but batteries cost a lot of $$ and you won't see more than 5% reserved for buffer these days -- or 95% usuable capacity.

Tesla also had software lock limiting access to extra battery capacity on the Model S -- 70KWh instead of 75KW, or about (7%?). No point in carrying around extra weight that costs $3,000 to unlock, but it probably helped prolong battery life.

That defeats the point of having a big battery. You're sacificing battery life to gain battery longevity

Yes and no. A battery's capacity isn't the only variable. You also have internal resistance. If you have a worn out to hell battery where there's dendrites on the anode and you've basically electroplated the cathode the internal resistance is going to be much higher. So if you draw the same current on a worn battery and a new battery the voltage drop is going to be way higher on that worn battery. If you're already at a low state of charge and you vdroop your way below 3.2V under the current load that battery is going to cut the current. Most people notice it as an Android phone that randomly reboots at low battery.

I've bought a phone with a big battery so I could do exactly what the GP said, always charge between 30-80%. But that means I'm cutting half of the potential energy in the battery.

I'm lamenting the fact that we have to do this even though film capacitors can be drained from 100% to 0% without damaging the capacitor or reducing its capacity. This is far closer to how you want an energy storage device to operate. Aside from the fact that film capacitors store about a thousand times less energy by every metric.

You need to do two things to keep a battery healthy: Keep it low current to stop the ions crashing into shit and not stuffing more ions than the anode and cathode matrixes can hold.

If you charge your phone to 100% using a ~4C 60W fast charger you're going to utterly fucking destroy your battery compared to someone who charges to 80% using a 0.5C wireless charger.

Like making anything last, don't operate at the limits of its envelope.

   * Limit max temperatures
   * Reduce maximum currents in and out
   * For lithium batteries, limit peak charge to 3.92V, do *not* charge to over 4.1V or 30degC

I can't find the specific research study, but NASA did a study that last I read was going on for over 30 years with a neglible drop in capacity by only operating in the flat portion of the charge/discharge curve. The result is that properly speccd battery packs (probably > 1.5x most battery packs) can last indefinitely. For my cordless tools, I get the largest modules I can (5Ah). I have a single slim 2Ah module for fitting in tight spots.

*edit, when using a cheap intermittent high current device, like a hand vacuum, apply a duty cycle, like 30 seconds on, 10-30 seconds off to prevent the internal battery pack from getting too hot. These kinds of consumer goods have the smallest battery pack that will outlast the warranty.

I really wish battery charge profiles were codified in QR codes on the modules themselves (besides existing on an I2C bus).

Short-Course on Lithium Ion Batteries https://ntrs.nasa.gov/api/citations/20190030819/downloads/20...

battery aging dataset (appears dead) https://c3.ndc.nasa.gov/dashlink/resources/133/

https://www.nasa.gov/wp-content/uploads/2021/10/3-nasa_batte...

https://ntrs.nasa.gov/api/citations/19990032333/downloads/19...

In the mid 00’s there was a set ACM papers about how a better scheduler in the OS could substantially improve battery longevity (lifetime and per charge) based on the observations that most batteries do worse the faster you draw current, and you’re better off load leveling to keep the discharge rate steady. So for instance instead of running the disk and CPU at saturation, reducing CPU use when disk was saturated and vice versa. The apparent speed of the system was affected less than the battery life was increased.

About 5 years later Apple bragged about how their new laptops without discrete batteries were 2x the run time of the previous generation due to the batteries being 1/3 bigger, 1/3 more power dense, and the operating system being 1/3 better at managing battery life. I’m fairly certain the latter came from someone reading those papers and taking them to heart. They had an advantage for the next few years.

3.92V is very conservative, that is a good voltage for long term storage even. It should be safe to charge to 4.05-4.10V regularly.

The NASA research really does support a 4.1V absolute maximum, with every reduction in charge voltage a dramatic increase in battery lifetime.

Some tools I use to actually follow this advice on various devices: I use Chargie devices (chargie.org - no affiliation) to control maximum charge level, and set thermal limits on smartphones and other small devices that can't limit charge internally with software. I also use a Peltier cooled phone holder and charger in the car (about $50 on Amazon), so it keeps the phone cool when charging and processing hard during navigation, and in direct sunlight. On Macbooks I use the free Al Dente app which lets me manage charge level. When I owned an e-Golf EV, I was able to set charge limits through the VW Car-Net app.

I just clip my phone cradle to an AC vent on the dash. I've been doing this since [checks calendar] 2014, when I retired the last phone I ever had that had a specialized window mount accessory available.

It cools when it is hot, and sometimes it warms when it is cold. Both things can be useful functions.

(Even on old junk I've had without functioning aircon, turning the selector to "Vent," the temperature to "Cold," and the fan to some speed other than "Off" works to circulate air around the phone.)

That works on some cars, but I prefer having the phone up high so I can keep my eyes on the road, and I drive a convertible with the top usually down, so like to leave the HVAC off.

I remember the first time I upgraded android phones and logging in triggered 100+ apps to start downloading. The phone got to hot to old, so I put it in the freezer. As a bonus the metal blocked enough of the wifi signal to meter the downloads. Not the best initial user experience!

Yeah, the Motorola Droid 4 was that way for me sometimes long after I began using it.

It wasn't clear what the combination of triggers was, but sometimes the Play Store would wake up and start updating everything that could be updated -- and do all of these updates in parallel.

Once or twice, it did this when I got in the car, plugged my phone in, and started driving -- sucking down what was (at the time) an enormous amount of [thankfully unmetered] cellular bandwidth and using enough power that the battery either would not charge, or would slowly discharge.

It'd get a pretty toasty.

TIL there's a name for this! (Chargie)

I have an old Mac multiport adapter (USB C / USB A / VGA) that I use only to limit the current going into my smartphone, for the sake of battery health. It effectively downgrades any fast charger to a slow charger. This looks nicer, thanks for sharing.

https://chargie.org/

The Chargie looks nice but ~6 of them for your devices gets pretty expensive.

I'm looking for some device like a 6-port Chargie... Or a 6-port charger like this Anker: https://www.anker.com/products/a2123?variant=37436925477014 that would allow you to control the charge status of each port via Zigbee / Wifi. Something like A/C smart plug functionality but for each USB port.

Anyone see that?

Do you really need one for every device you own? Having it just for my phone is mostly fine. It is possible to configure a chargie to limit charge level based on current draw on non-phone devices, but complex, and usually not worth it in my opinion, I only use it for my iPhone.

I wish I could find this information for LFP batteries. There’s a lot out there, but it’s all mixed with advice for LiPo; I can’t find anything I trust to tell me the optimal voltages for maximum lifetime.

Is it possible to reach out to the manufacturer, or the place you;re buying your batteries from?

I was told that LFP is difficult because the battery management system (BMS) cannot reliably guess the state of charge using the voltage. The voltage is a mess on LFP.

Even though a lower voltage prolongs the battery, you have to charge to 100% regularly to help the BMS. Thankfully the LFP chemistry doesn’t seem to mind high state of charge as much.

As a popular source, Tesla recommends to daily charge the LFP batteries to 100%.

> The voltage is a mess on LFP

That's a weird statement. The voltage curve for LFP [0] is just a lot flatter. That's nice for your electronics, but makes it hard to estimate state of charge based on the voltage alone. So the BMS needs to keep track of total energy used to calculate state-of-charge.

[0] https://www.jackery.com/blogs/knowledge/ultimate-guide-to-li...

Excellent link, thank you!

True, it’s very flat. And If you add some major temperature changes over many days and a descent amount of non full charging cycles, it’s more challenging. Maybe I wasn’t told it was a mess, but it’s how I remembered it.

The problem is that total energy used is never fully accurate so coulomb counting can only be so good. Top and bottom balancing is needed to reset the algorithms, otherwise state of charge is largely a guess especially over time.

The 100% charge thing is also for balancing, as most BMSs are pretty dumb and only use passive balancing.

When an individual cell reaches a set voltage, a resistor is turned on which bleeds the excess power preventing that cell from overcharging. When the pack reaches 100% theoretically every cell should then be at the same voltage.

If that's the case, then if you don't regularly charge to 100% you can end up depleting any cell that's out of balance. Good to know.

Lfp voltages are all over the place and even after charging to 90% the voltage drops back down. They might not care much at all being charged to high percentages. There is no reliable way to know the SoC other than coulomb counting and regular 100% top balancing.

LFPs are indestructible and last forever.

For general advice, they like it cooler[1] than other kinds of lithium batteries. Try to keep them between 15-25°C. Other than that, charge LFP batteries to whatever percentage you want whenever you want.

They are simply better than every other kind of lithium chemistry. Their practical downside is lower cell voltage (3.2 vs 3.8), and slightly lower energy density. I've spent the last 7 years building LFP-powered lawnmower-sized robots, and in practice, the lower voltage and doesn't matter. And, unlike other chemistries, they don't catch fire when you stab them.

For other kinds of lithium batteries, to maximize lifetime, keep them between 40-60%, avoid big charge swings (10-90%), and keep them warm (above 25°C).

[1]: At 35°C, tests show they lose about 5% more capacity after 2,000 cycles compared with 25°C. But even that isn't really a problem, because they don't get to 20% capacity loss until 4,000 cycles. See: https://iopscience.iop.org/article/10.1149/1945-7111/abae37, fig 3.

A practical concern is that the batteries in question will be powering our cottage, which is entirely off-grid.

It’s also unused for half the year, and for much of that half the solar input is effectively zero; for part it’s literally zero. Not enough to even run the Victron gear, never mind a heater. Spring temperatures often drop below -5C.

So we’ll winterise it by shutting everything off, BMS included to the degree it’ll let us, and the question is what SoC they sold be at for that to work.

Cold batteries do struggle a bit to deliver power and charge when they're cold, but they're just fine being stored in low temperatures. LFPs are really good at maintaining their charge. Even below -5°C, they should be fine, particularly if they're not being used.

Also, I wouldn't worry about the BMS too much. Unless it's really dumb, when there's no charging or discharging happening it will put itself to sleep for most of that time. Technically it will use power, but likely only a few hundred micro watts to a few milliwatts (nothing that will make a difference on a 5 kWh+ battery). Then when the sunlight comes back in the spring (or whenever the snow melts off the solar panels), it'll see some input voltage and start feeding the battery again.

Two unconventional things I do to improve my iPhone's battery health (which follow this article's findings): 1) Don't use a case - Otherwise, you are literally wrapping your phone in a rubber insulator 24/7, increasing its overall temperature. 2) Don't charge at night - Turn off your phone at night. Instead, charge it during the day when you're at your desk. This reduces the number of cycles over years (because your phone is continually draining/recharging all night even when you aren't using it)

iOS will not fully charge your battery during the night - it will top off the battery just before you usually take it off the charger in the morning (it learns your usual schedule + it probably also makes sure the battery is ready based on your alarm settings).

In the US there's also an iOS charging option that considers the local grids carbon intensity.

https://support.apple.com/en-gb/guide/iphone/iphc49d61e92/io...

This feature doesn’t help. The problem is that the phone is still using energy during the night, draining the battery by, for example 8-10%. Over several nights, this adds up to 1 cycle.

The fact that the OS waits to top up the battery just hides how much energy it used on background activity and notifications during the night.

Can’t use the battery if the device is shattered. No case is not an option for my clumsy self.

Turning off my phone at night is not an option. I want to be contactable in case of emergencies.

> because your phone is continually draining/recharging all night even when you aren't using it

Are you sure of this? What are you basing this on?

When the phone is on, it’s powered by the battery.

Plugged-in phones should use power directly instead of passing through and degrading the battery.

They do, energy can't pass through a battery on the way to powering something. It just skips the battery and directly powers the device.

1. It’s ok to keep laptop plugged in, even at 100% battery

2. Keep temperature as low as possible, maintain airflow

3. Avoid fast chargers

I wish more devices offered a way to enable a “slow charge” mode.

When I’m plugging my laptop into my dock to work for the next 8 hours it doesn’t need fast charging.

When I’m plugging my phone in before bed to charge for the next 8 hours it doesn’t need fast charging.

i have 2 chargers near my bed, one has 3 amps, the other one has 1. i use one on another depending on how fast i need it charged. not the best solution, but it works.

I have a wireless charging cradle on my nightstand intentionally hooked to a slow charger. It works fine most of the time except on the rare occasion when the phone charge is low and I'm going somewhere in a couple of hours. It would be great if there was a charging cradle with a simple "fast/slow" charge switch.

Or even better, if phones had a built-in charge status UI that instead of just saying "NN% charged / TT minutes until full" had a slider controlling charge speed that showed a range of "time until full". That way users could intelligently choose the charge speed vs time based on context.

At least on Android it's possible to disable fast charging. It's in the battery settings on my phone.

> When I’m plugging my phone in before bed to charge for the next 8 hours it doesn’t need fast charging.

iPhones do this with "Optimised Battery Charging" turned on (which I believe is the default setting) - "allow iPhone to wait to finish charging past 80% until the time you need to use it" (which it learns over time.)

Android has something similar. A notification pops up when I plug in at night, letting me know that it's charging slowly because I usually leave it plugged in overnight, and that I can disable it (once or permanently) to switch to fast charging.

On my laptop I have a script to set

    /sys/class/power_supply/BAT0/charge_control_end_threshold

I could imagine automating this to set the threshold to the current battery level, and incrementing the threshold by 1% every N minutes to control charge speed.

Right now I try to keep it at 50% max charge like this while plugged in at home.

As others have mentioned, many phones do this in software, but I find the easiest solution is simply to use a charger incapable of fast charging.

It's harder to do with a usb-c charger and laptop because the spec requires higher voltages are made available with higher wattages, and manufacturers only make products to hit sweet spots in the specs and market.

You might end up with a readily available 65W charger to get the necessary 20V, even if you don't want 3A.

https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Deliver...

>1. It’s ok to keep laptop plugged in, even at 100% battery

It might be "ok" to keep it plugged in at 100%, but if your laptop has a "battery conservation" mode that limits the charge to 80% (or similar), that's even better.

If you're on a Mac, you can install the free version of AlDente:

https://github.com/AppHouseKitchen/AlDente-Charge-Limiter

I keep my MBA at 60% since it basically never goes for more than a couple hours within being plugged in.

Also batfi - https://github.com/rurza/BatFi

Oh wow, looks like that's brand-new (from March?) as opposed to AlDente which is about 4.5 years old at this point, at least according to GitHub releases.

It looks really really sharp, the UX is definitely much more visually appealing than AlDente. I might have to check it out.

I think (though I might be wrong) charging of Apple hardware detects usage patterns and it would already not charge the battery to 100% if you’re frequently plugged in.

Kind of, it's described here [1].

But that only applies if you have a "charging routine", e.g. you always charge overnight and use it on battery all day long starting at 9:15 am:

"When the feature is enabled, your Mac will delay charging past 80% in certain situations. Your Mac learns your charging routine and aims to ensure that your Mac is fully charged when unplugged."

But in my experience, the feature doesn't do anything if your Mac is just usually plugged in. It simply stays at 100% because there's no routine for it to learn for when you tend to unplug it.

[1] https://support.apple.com/en-us/102338

Useful info, thanks. There’s really no reason for my MBP to be charged 100% - I rarely unplug it

> 3. Avoid fast chargers

Isn't this primarily due to heat produced? Aka cool fast charging is better than warm slow charging.

I seem to remember a tweet I think by Mishaal Rahman (or another android journalist) on this.

Yes that's absolutely the case. So it just depends on how good the cooling system is. For a phone, it has no active cooling system. For an electric vehicle, almost all manufacturers (except Nissan Leaf) have adopted active cooling and you can expect them to do a good job activating adequate cooling for the battery.

In absolute terms, cooler isn't always better.

For example, Tesla has a pre-heat function for their cars' batteries that can be used prior to charging.

https://www.tesla.com/ownersmanual/model3/en_us/GUID-F907200...

That affects charging speed, not battery longevity.

It can affect battery longevity. If you charge lithium ion at cold enough temperatures, you get lithium plating which rapidly degrades capacity and can lead to internal shorts and fires.

It's due to heat produced, gas generated from overvolting the battery, and stress gradients from different levels of charge across the battery.

I disagree with your point #2 as it is written. You want to keep you battery close to the temperature at which it is rated. Cycling below that also harms batteries and shortens their life. If you really want to geek out about that, I can recommend for example a talk [1] that was given last week (you can jump to slide 15). The presentation has nice electron microscopy images of the cracking this type of abuse causes in batteries.

[1] https://academy.covalentmetrology.com/wp-content/uploads/Bat...

I've been using ACCA[0] to set limits on battery charging on Android devices for years. Note that it requires root.

ACCA can limit charge percentage, allowing the device to operate plugged in without charging beyond a certain point. It can also pause charging when the temperature exceeds a threshold, limit the charge rate, and several other tweaks to charging behavior. By default, I use a charge limit of 60% and a charge rate of 500 mA, increasing those when needed.

[0] https://f-droid.org/packages/mattecarra.accapp/

This sounds great and is exactly why having root is valuable. Unfortunately, I've given up having root because the cat-and-mouse of staying ahead of manufacturers updates became too burdensome and I wasn't willing to constrain my phone choices to only device with accessible root.

It is unfortunate few devices come with unlockable bootloaders. I take a harder line on that issue; I see it as a malicious decision by the manufacturer and a very strong reason not to pick a particular device.

I run LineageOS and don't have to concern myself with manufacturer updates. That's not to say everyone should take that approach; it does involve more effort and demand more knowledge than leaving the OS stock.

Charging at 1C or less on phones would mean 20W on a 5000mAh battery. For laptops it would be 100W maximum, probably 65W or 45W for most laptops. All the Dell laptops I have allow me to set a low percentage and high percentage, and I have the high set to 55% on laptops I use primarily plugged in, and 80-90% on more mobile laptops. Now if only Pixel phones and ereaders/watches/battery banks also allow me to have such control over how much to charge.

Would be ideal to have LFP batteries and such control, but that will take a while.

I think all systems that allow for fast charging should, after plugging in, ask: "Do a slow charge instead?" and perhaps: "Only charge to 80%?". These could be two check boxes that are unchecked by default. Maybe you could change the default in the settings.

Anyway, the way this is currently solved e.g. in Android is clearly suboptimal. You can only configure charging in the settings, but obviously it depends on your current situation whether you want to use your device immediately and need a full charge.

I actually have a couple of chargers that just do _exactly_ 5V/1A for this reason.

Yeah, but a software solution would be better and actually easy to implement.

True, that is what _should_ have been done in the first place. But I have given up on companies caring about battery life of products, when their business model is exactly getting their products obsolete as fast as possible for people to get the new product, and hindering self-repair as much as possible.

I think it is more likely the developers of operating systems are just not aware of some obvious things. E.g. it took them years to introduce a dark mode and to adapt the color temperature of the screen to something warmer during the night.

Every Apple device (even headphones!) does this by inferring your schedule and charging to 100% just in time or just never if for example you charge your watch every night but only use half the battery. I just wish it was slightly less automatic because it definitely gets tripped up by my occasional insomnia.

That's something else because it assumes a stable schedule, while I proposed dynamic options that can be activated once the charger is plugged in. Just let people optionally choose how far and how fast they want to charge this time. The default can be as "smart" as it already is.

The algorithm is very finicky. Often it doesn’t detect the pattern and charges to 100%.

All Galaxy phones have a configuration to limit the charge to 85%

Recent updates have changed that. The limit is now 80%. Also some more options (like not staying at 100%, but bouncing between 95% - 100% when plugged in to a charger overnight) were added.

Note that in most battery chemistries, the degradation floors at around 80% whatever you do.

These advices are to get to that 80% slower. If you are fine with having 80% in like 2 years instead of 10 years, you don’t have to really limit yourself.

A better way will be manufactures to advertised 100% as current 80% and allows you to boost you to 120%.

Check the article, it contains a graph where the capacity is reduced to 10%.

The worst I am seeing is 78% in figure 6.

Obviously, I am not talking about charging your battery at higher voltage than advised, but comparing 0-100% (least optimal cycles) to 40-60% (most optimal cycles).

I've been doing 80% >> 45% for a while on a 14 pro max....on a best effort manual basis.

Appears to be working...I'm on 93% battery health today while googling suggests others where hitting <90% in mid 2023 already.

So unscientifically it does seem to matter, though whether it is worth the hassle is another question

For what it’s worth, I don’t pay attention to my charging habits and my iPhone 14 Pro Max is at 92%

The article mentioned heat. I park my ev in the sun in CA. Definitely hotter than 86 degrees. Does the car protect the battery somehow with cooling, or do I need to find shade asap.

Varies by EV. The 1st generation Nissan Leaf was famous for overcooking its own battery pack because it didn't have the capability.

Also worth pointing out that the original Nissan Leaf is now at least 13 years old, a lifetime ago in lithium battery tech, and intentionally used very cheap cells to keep the cost down.

My car will run the AC on the battery whenever it needs to, even if I'm away.

ill have to check: its a 2023 bolt euv

Bolt will cool itself, but it does so more aggressively when plugged in (even if not actively charging). I always leave our EVs plugged in when it's over about 80F and below freezing because of that.

My 2021 is complaining loudly (running the cooling system) about the heat-wave today.

Thanks for that info. I'll definitely keep it plugged in then.

I would avoid charging at high temperatures, or rapid acceleration when the pack is hot.

Every time I hear about that stuff, I see this website listed as source. What is their source?

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