Xiaomi claims its new battery technology increases battery capacity 10%

There are many factors in a battery.
Energy stored vs mass
C rate
Price
Charging cycles...Can they be fully discharged and fully recharged without increasing the degradation rate?
Charging rate and charging method. e.g. is a cell balance and or thermal monitoring system needed.
Materials needed (e.g. cadmium, nickle)
Ease of recycling
Depletion rate when stored
Swelling

Just as an example... DJI Inspire batteries (and perhaps others) self discharge to 60% after about a week to protect them since storage at 100% is bad for them. Whereas most of the time we don't charge and discharge our batteries in the ideal way for the longest service life.

Dec 14, 2021*permalink

Stefan Hundhammer

What use is a longest service life to me when I find the battery half-discharged when I need it?

Those ubiquitous batteries in all devices need too much babysitting all the time already. An intentional self-discharge only makes that worse: Then you have to remember to top them up the evening after you need them. That means more planning, more manual work, more babysitting.

This is the thing that NOBODY wants.

Dec 15, 2021permalink

I want that. It's not a problem for a smartphone which is discharged gradually during the day, or a drone flown every single day. It's a solution to idle batteries. Why do you think rechargeable batteries are shipped somewhat depleted? Batteries store best close to their nominal voltage.

It's a solution to decreased battery life cycle. Which is good for the longevity of the product, the environment and your wallet.

A Li-ion battery (as the ones in tesla) can have a 10-fold increase in lifecycle if you charge them between 40% and 80%, as opposed to deep discharge/charge.

Stefan. It's a good thing. Until we get better battery technology (solid state).

Dec 15, 2021permalink

AlanG.

Great summary - just remember discharge rate (max and continous).

Another concern that goes into batteries would be the mah capacity vs max discharge rate in amps (basically how fast the product needs the power delivered).

The bigger the draw - the smaller the battery capacity typically is.

They could basically solve it by reducing the max amp-draw, which typically means that the battery has a larger mah-capacity.

Dec 15, 2021permalink

@Stefan Hundhammer - it's exactly what I want. If my Phantom 2 batteries had that feature (or hadn't had a bug that prevented it from working, I forget what), they wouldn't have become useless in <9 months

Dec 15, 2021permalink

"Why do you think rechargeable batteries are shipped somewhat depleted? Batteries store best close to their nominal voltage."
That's one of the reasons. The more pressing one is legal, by law they are shipped with the charge range least likely to self ignite.

Dec 15, 2021permalink

Being dead when you need it, especially critical items that are only occasionally used suggests a different strategy.

The emergency flashlight I keep in my car is a standard C cell type. I also carry brand new alkaline cells in a separate container. Quality alkaline cells have a shelf life of 5-12 years depending on brand, so I never need to worry about being caught with flat batteries.

Dec 15, 2021*permalink

Jxh. Wuth all due respect, thats like comparing the shell life of fresh oysters to canned tuna. We`re discussing li-ion batteries that can handle high amperage discharging. They have a fundamentally different chemistry to handle much, much higher draws.

Alkaline batteries are a completely different ball game. Theres a reason you cant pop in 200 x AA`s to top up a Tesla.

Dec 15, 2021permalink

"Wuth all due respect, thats like comparing the shell life of fresh oysters to canned tuna. "

My point was that different problems require different solutions. Rarely used items have different priorities than frequently used items.

Dec 15, 2021permalink

Still think you are missing my point. What about rarely used items with a high power consumption?

What good is the comparison with alkaline batteries for that use case? I get your point, but honestly dont get the relevance wrt cell phones, drones etc that use Li-ion.

Dec 15, 2021permalink

The lithium iron batteries used in many cars can be heavily cycled so they should have a long life. They have a bit less density than NMC lithium batteries.

But if LiFe batteries can give a car 250 miles of range on a 100% to 0 cycle vs the same distance on an NMC battery in an 80% to 20% cycle then it may be a better choice. Especially if it is cheaper, uses more common materials, and is less likely to short out. (Maybe impossible to short a BYD Blade battery.) LiFe are perfect for stationary storage.

Countless companies around the world are researching new battery technology.

Btw drones use LiPo which is different still.

Dec 16, 2021*permalink

@Snaphappy32 I build drones and use LiPos. The same capacity and voltage can be purchased with different discharge rates.

While a lower C rated battery may lift my machine and fly it...if I demand too much thrust, it could fail to supply the required power. Additionally that battery can swell up and be permanently degraded pretty fast. This is why many machines have sophistucated power management. My Inspire limits full throttle ascents whereas my homemade ones don't.

Dec 16, 2021*permalink

AlanG. Thanks for elaborating.

Was exactly the point I was trying to make. There is a discharge / capacity trade-off.

I mistakenly assumed that drones would utilize standard Li-ion cells, but makes much more sense to use more malleable, lighter (and safer) LiPo.

Dec 16, 2021permalink

https://oscarliang.com/li-ion-battery-long-range/

The drawback in LiPos is they don't have as many charge discharge cycles as Li-Ion. And they don't have the power density. But they can supply higher current. A very small number of RC applications are using Li-Ion for long distance flying that doesn't demand high current.

Dec 16, 2021permalink

Rob890

a measly 10 %?.....wow hold the phone and stop the presses folks

Dec 14, 2021permalink

Given that we are near the limit of what physics allows that's quite an achievement. And I'd still worry about safety even with this modest increase

Dec 17, 2021permalink

What is REALLY needed is easy user battery replacement (as in cameras).

Dec 14, 2021permalink

We used to have that couple of years ago. Manufacturers took that away following Apple's lead and using waterproofing as an excuse,

Dec 14, 2021permalink

The first batch / generation of Android phones with sealed batteries weren't even weather sealed at all IIRC, I think the rationale was thinner designs and different build materials...

I honestly wouldn't mind a high end but plastic fantastic phone where I can still pull the back off and swap the battery, tho a battery replacement after ~2 years isn't that hard on most phones either. Ironically it's becoming trickiest on laptops where they're often glued in and even harder to disassemble.

Dec 14, 2021*permalink

Jesse_Just_Him

And also premium glass back too

Dec 15, 2021permalink

Stefan Hundhammer

@jxh: Exactly.

Yet the usual battery blow-up (which almost inevitably happens when it nears the end of its lifetime) makes the whole device a disposable item instead. Or you can spend ~100 EUR on a repair to completely disassemble the thing to get a new battery, and get it pretty much scratched up in the process.

Considering how huge those smartphones have become, what's the problem of having them 1-2 mm thicker to be able to open them for easy battery replacement? But no, the product designers insist they need to look thin and sleek; but insanely tall and wide.

Smartphone technology reached total degeneration in recent years.

Dec 15, 2021permalink

mermaidkiller

"but insanely tall and wide"
Indeed more tall and narrow you mean. An aspect ratio of 2.2:1 is ridiculous. And why do smartphones have an inevitable portrait mode while other screens are landscape ?

Dec 15, 2021permalink

I thought I was gonna mind the narrower aspect ratio of most recent phones but on a (relatively) small Pixel 5 it's no big deal, I'm sad that something like it is now what's considered small tho (there's the iPhone mini that's a bit smaller I guess but slim pickings for smaller stuff in general).

Dec 15, 2021permalink

I have a thin LG phone with a replaceable battery. And a similarly thin Samsung phone with a fixed battery. Neither is water proof. The Samsung is in a waterproif case that makes it twice as thick. So bring back the replaceable batts.

Dec 16, 2021permalink

"Or you can spend ~100 EUR on a repair to completely disassemble the thing to get a new battery"

I spent €25 on that, which was acceptable. However... the phone can't be glued back. It holds for a week or so and then a gap appears. I kept sending it back three times, nothing helps.

All props to Apple for making phones and laptops f****** jewelry items that for some reason need to be as thin as possible, because that's apparently the most important thing ever. And then you pay premium for a flagship CPU that gets thermal throttling after 3 seconds because the heat has no way to go.

Dec 17, 2021permalink

Nikita66

Of course, "flagship devices." I was thinking camera replacement batteries. But cost will probably suck the enthusiasm out of this tech anyway.

Dec 14, 2021permalink

garyknrd

Good phones also..

Dec 14, 2021permalink

pollup

What's crazy is that we already solved the battery problem a long time ago with the atomic battery (or nuclear battery).

Dec 14, 2021permalink

Revenant

Among other things, those are used in pacemakers, right? Sounds expensive.

Dec 14, 2021permalink

No, we have not solved the battery problem because atomic batteries have very limited use, supply and are very-very expensive. I think not many would buy a $5000 phone.

Dec 15, 2021permalink

Antisthenes

The atomic batteries that were used e.g. in cardiac pacemakers were tiny radioisotope thermoelectric generators (RTG), which delivered electrical power in the milliwatt range.

A digital camera recording 4K or 8K video can easily pull 10+ watts of electrical power, which is noticeable by the user because that consumed electrical energy, ultimately, heats up the camera.

A terrestrial RTG that generates 10 watts — instead of a milliwatt — of electrical power, like those used by the Russians to power uncrewed lighthouses, can weigh about 600 kilograms.

So, the battery problem is "solved" [sic] if one assumes that a normal user is willing to put up with an expensive, bulky and radioactive camera battery that weighs several hundred Kgs.

Dec 16, 2021permalink

sludge21017

What's the GoPro enduro made out of? That's got some serious increase.

Dec 14, 2021permalink

TN Args

I was kind of hoping for 10% every year or two…

Dec 14, 2021permalink

Sure, if e can get the laws of physics change every year or two too then no problem :)))))))

Dec 17, 2021permalink

TN Args

Sorry mate, but battery tech changes steadily, and sometimes lumpily, without the laws of physics needing to change too.

Dec 18, 2021permalink

"Sorry mate", but no. There's a limit of how dense the energy can get before getting dangerous.

Jan 9, 2022permalink

snapa

I am looking forward to batteries made from dilithium crystals that can power a car for 5 years or more, the size of todays 12v batteries. Once that happens, I may consider an electric car. ;)

Dec 14, 2021permalink

astirusty

So outdated, sort of.
New 28,000 year power source, Nano Diamond Nuclear battery. It's green too, since it uses nuclear waste. Target market is watches and cellphones.
Although you would need a whole lot of them stacked together for a car.

Dec 14, 2021permalink

Adrian Tung

Looking forward to Epstein Drive myself.

Dec 14, 2021permalink

User4286416121

Better than queller drive 1999.

Dec 14, 2021permalink

@Adrian Tung - gotta be careful, anyone who hasn't watched The Expanse might think you're talking about a different Epstein...

Dec 15, 2021permalink

Adrian Tung

Haha good point, sasa

Dec 16, 2021permalink

Dilithium doesn't "power" anything. It is used to control matter-antimatter reaction, you still need antimatter for this to work, DUUUUH

Dec 17, 2021permalink

Jon Stern

Lithium-ion capacity has been increasing around 3% a year for quite a while.

Silicon has been added for a long time, but it swells and reduces the cell life. There are a number of teams trying to overcome these issues (the latest I've seen is silicon nanowires).

The question here is has Xiaomi reduced the cell life by adding more silicon?

Dec 14, 2021permalink

photo_rb

Good question, I'm following the silicon/solid state topic in electric vehicle batteries and as much as they'd like to increase the silicon, the deterioration factor is a huge problem to overcome.

Dec 14, 2021permalink

quiquae

The diagram shown in the article suggests that they’re peppering the anode material with silicon nanoparticles, an idea that has been in the works at various companies for over a decade. Xiaomi and/or its contract battery manufacturer probably licensed the technology from one of them—this isn’t the type of technology that you can throw money at and invent overnight.

Dec 14, 2021permalink

Kondamin

It would be cool if I could pop it out and replace it on the fly on a modern high end phone

Dec 14, 2021permalink

mxx

Those were the days, right?

Dec 15, 2021permalink

dr8

So then, instead of sticking the 10% more capacity into the same size battery/phone so as to have an actual increase in use time, they appear to have made the battery smaller... Hey, my car gets 75MPG, but it only has a 3 gallon tank...

Dec 14, 2021permalink

onlyfreeman

I always felt Xiaomi phones were giving me 10% less battery life than I expected in comparison to other phones. I guess this will finally fix that issue.

Dec 13, 2021permalink

badi

not really... it looks like they made the battery smaller, with the same capacity :)

Dec 14, 2021permalink

Z6User

Actually battery capacity has been steadily increasing over the years, look at 18650 lithium cells, they used to be 2000 mAh, now 3600 mAh cells are available. Don’t listen to marketing handouts.

Dec 13, 2021permalink

McArchive

Dewalt made all their 18v batteries 20v using only a pen! It can be done by all those with the vision bold enough to try!

Dec 14, 2021permalink

In our designs we use as large as 4000mah 18650 which have a 30A discharge and also the larger 21700. Interestingly we moved some designs to pouch type about a year ago.

You absolutely right how things have developed over the recent years. Will be exciting to know what the next big step will make it commercially.

As for 20V well I guess it looks bigger 😇

Dec 14, 2021permalink

davev8

the Dewalt battery is 20V ish..as is all power tool batteries ....when they are not under load ..when you are using them they drop to 18v ish

Dec 14, 2021permalink

davev8
the Dewalt battery is 20V ish..as is all power tool batteries ....when they are not under load ..when you are using them they drop to 18v ish

Indeed. We aim to charge to 20.44v but that isn't always possible due to some imbalance or we cutoff due to low current before that.

In use the battery can be a long way below 18V.

We create software for the platforms and also battery simulators (so we can test powertrains with different states and health's of batteries).

18v comes from a cell mid point being 3.6v. this is taken as the half way point between charged and cutoff in terms of energy and forms the legal requirement for the battery capacity which is found to the base of the case. This is a European driven requirement but it is also applicable to other geography.

Dec 14, 2021permalink

Ephemeris.

Is that peak 30A or continous discharge for a 4000mah 18650-cell?

That sounds like 21700-cell performance. Not 18650. Mind telling me who makes these? Nothing Samsung, LG or Sony-Konion makes fits the bill.

Thanks.

Dec 15, 2021permalink

Ephemeris.

Is that peak 30A or continous discharge for a 4000mah 18650-cell?

That's <75°C </= 1s. The cells are now manufactured in Asia but originally in the Midlands UK.
Outside of SBD some brands are using 18650 in a 5s2p to creat both 8Ah and larger batteries but maximum current and number of recharges obviously affected.

We do have a 21700 cell but using two 18650 cells in parallel to then create a 2 X (5s3p) is our direction for the very high power tools (above 2200W).

For SBD LG and Samsung provide the majority of the cells, some custom but most are not (they are tollerance batched).

That sounds like 21700-cell performance. Not 18650. Mind telling me who makes these? Nothing Samsung, LG or Sony-Konion makes fits the bill.

Thanks.

Dec 15, 2021permalink

Thanks for the answer. If I understand you correctly, those 18650s are custom made?

Wow. I wonder how far they can push the 21700s.

Dec 15, 2021permalink

kelpdiver

so is it also 10% more thermal runaway potential?

Dec 13, 2021permalink

Kris Hary

You know I'm getting more and more worried about batteries, I have them everywhere in the house, phones, tablets cameras, chargers galore. All you really need is one fire to have a bad day, yet I havent heard of (other than from the news about phones a few years back) about any fire from the hundreds of people I talk to*

*other than electric cars burning down multiple households (in a city house environment)

Dec 14, 2021permalink

kelpdiver

I've had problems with UPS batteries swelling up, to the point where removal required the destruction of the unit itself.

my phone can get hot enough to be mild burn risk.

Dec 14, 2021permalink

Djehuty

just means ill charge 10% earlier.

Dec 13, 2021permalink

So same size, but what about weight?

If only batteries developed at the pace of hard drives.

Dec 13, 2021permalink

kelpdiver

it's a lot easier to use less energy than to create more of it.

Dec 13, 2021permalink

madsgrand

I think they actually kinda do. Lithium ion batteries especially those that goes into cars have developed magnitudes over the last 15-20 years. So much research goes into new battery tech and I'm sure we'll se another level of performance in the next 10 years

Dec 14, 2021permalink

https://pubs.rsc.org/en/content/articlelanding/2021/ee/d0ee02681f
https://pubs.rsc.org/image/article/2021/ee/d0ee02681f/d0ee02681f-f8_hi-res.gif

4x improvement in the last 20 years is no where close to what hard drives have achieved.

Typically hard drive from 2001 was 30-60GB.

Dec 14, 2021permalink

75GB was freaking cutting edge in 2000, and I was the unfortunate guinea pig, RIP IBM Deathstar (Deskstar) 75GXP. Oh and of course when I bought it heading into college someone said "75GB?? OMG you'll never fill it", aged about as well as any of those sorta comments do.

Dec 14, 2021permalink

I don't think the 75GXP was actually 75GB - that was just a model number applied across all Deathstars.

(Although I'm seeing evidence there was a 75GB version available - but most were much lower capacity. I think my Deathstar was a 15GB unit.)

Dec 15, 2021permalink

The 75GB 75GXP was the top of the line model with 5 platters (which i think was kinda nutty at the time too), I'm 100% sure I owned one as it was one of the last irrational PC parts purchases not paid out of my own wallet, heh.

I think I ended up replacing it with a 60GB or 80GB Maxtor around mid to late 2001, I was lucky I didn't lose a bunch of data on the IBM... I woke up one day and everything on my desktop was gone, turns out the folder had somehow gotten renamed to Desotop but nearly everything was in there still.

Platter density had gone up by 2001 IIRC and drive costs had come down somewhat, tho I imagine the average drive sold was still < 60GB.

Dec 15, 2021*permalink

" last irrational PC parts purchases not paid out of my own wallet, heh" - Heh, I know that feeling. I would not own a Jabra evolve2 85 if it were out of my own wallet. ;)

I definitely owned a Deathstar back around then, not a 75GB model, but definitely a Deathstar that lunched itself.

Dec 15, 2021permalink

pack 10% more capacity into batteries the same size of traditional lithium-ion batteries.

according to Xiaomi, this new design gives 10% more power in the same footprint.

Is it 10% more capacity OR 10% more power OR both?

Great to have some advancement however just not clear on the outcome

Dec 13, 2021permalink

capacity = power, it is measured in watt-hours

Dec 13, 2021permalink

Capacity is measured ultimately in Joules.
Power is the rate of change of that energy, so joules per second which is the Watt.

Watt hrs is a unit of capacity. let's go back you J/s. We now multiply the denominator, s (a unit of time) by hrs (just a lot of seconds) and they cancel leaving Joule which is energy.

Other posts last week across the web only spoke of more capacity per unit volume, specifically 5500mAh Vs 5000mAh. I don't recall the mass being discussed or how the maximum current may or may not be affected.

Dec 13, 2021*permalink

I doubt they made a battery with higher capacity, but with insufficient (for an intended cellphone) output current. That would just not make sense.

Dec 13, 2021permalink

I doubt they made a battery with higher capacity, but with insufficient (for an intended cellphone) output current. That would just not make sense.

I didn't say insufficient current.
The OP suggests 10% more power which I think is an error.
The posts from Xiaomi discuss the technology to improve the capacity per unit volume by 10%. Weight doesn't appear mentioned.

The 'fuel guage' chip and associated algorithms which will be added to every battery is mentioned.
New packaging is mentioned.

With the vastly increased Si doping they will have expansions issues Vs State Of Charge so a new container is needed to keep this battery safe (as safe)

Dec 13, 2021permalink

PhotoKhan

A whole new technology and just a 10% gain? Color me non-impressed.

Dec 13, 2021permalink

Kerensky97

Look at your bank account or your investments and ask yourself if you'd turn down a 10% increase.

Dec 14, 2021permalink

PhotoKhan

Exactly the same. Brilliant!

Dec 14, 2021permalink

I gave him a like. Maybe not brilliant, but still a great analogy.

Your mistake is the “new tech” assumption.
Its proven tech, and an adjustment that brings a tradeoff with it.
If you’d care to investigate there’s a good explanation in this thread.

10% is a good improvement.

Either you care or you don’t. What’s the point in complaining?

Dec 15, 2021*permalink

Jake2046

increment upgrade...better safe then sorry.

Dec 13, 2021permalink

nand

10% is a lot when it is sales tax. So it must be a lot.

Dec 13, 2021permalink

Even worse when it is inflation.
So this must be huge.

Dec 13, 2021permalink

JasonTheBirder

10% would not be a lot if I could charge my bank account as easily as a phone.

Dec 14, 2021permalink

Franz Weber

10% alcohol is just fine. 10% intelligence is very sad

Dec 15, 2021permalink

10% is obviously a valuable improvement but I believe the focus should be on the following things instead, capacity coming last: battery lifetime, safety, charging speed.

I want batteries that can be used without degradation for 5-6 years, not just 2 or 3 and don't need to worry about explosions, swelling, fire, etc.

Dec 13, 2021*permalink

All they need to do is give people a software option to never charge beyond 80% unless they NEED a full battery's worth. Most people don't. Problem solved.

Not that Apple junk of "we'll try to guess when you depart and charge to 100% then" - I want my device to NEVER charge beyond 80% unless I explicitly ask it to. Heck, given how often I've got access to a charger, I'd love 70% - because then I could just leave it on the charger all the time.

My Yuneec Typhoon batteries are now 5 years old with very little degradation because I bought a charger that let me NEVER charge them past 4.1v/cell, and discharge for storage. Compare to my DJI batteries which all swelled in <9 months.

Dec 13, 2021*permalink

'Swelling' reminds me of having 1x Samsung tablet, 2x Xplore tablet, both busting at every seam possible....;((

Dec 13, 2021permalink

User1234567890

If you use 5W charger, battery will last longer.

Dec 13, 2021permalink

If you don't charge your battery over 80% then it's the same as if its capacity have already degraded by 20%, so what's the point? Also, you have to recharge your battery more often.

Dec 13, 2021permalink

The 80% charge doesn't extend the battery cycle life by much. Often when electric cars do it, it is to offer more consistency over the first few years of use.fir example, a quality li-ion cell will gradually lose 20 to 25% of capacity over the course of 700 to 800 charge cycles. If you set the design capacity to 80% of actual capacity, then you can offer predictability, in terms of range.

It is also rare for any device to charge to 100% of actual capacity, even smartphones do not do it.

Dec 13, 2021permalink

That's like saying make a light bulb last forever. They tried with LED, but somehow the manufacturers found a way for them to still burn out.

Greed is what holds tech back unfortunately.

Dec 13, 2021permalink

"Greed is what holds tech back unfortunately."

The world is not that black and white. There are many factors, like technology and physics. If someone has a better technology they will the first to market it and make billions from it. Makes no sense to hold it back until someone else develops a better technology.

Dec 13, 2021*permalink

onlyfreeman

It all depends how much you use your phone or device, if you are a light user the battery can easily perform well for 5 years.

Although improvements in longevity would be welcome, then we just need phones that are built with quality materials that will also last as long as the battery.

Dec 14, 2021*permalink

Leitz

Andyyy, LiFePo4 is your answer, Can be recharged over 2000 times until it reaches 80% of it's capacity vs 500 times for Lithium-ion. It is also a stable chemistry, very safe to use.

Dec 14, 2021permalink

"If you don't charge your battery over 80% then it's the same as if its capacity have already degraded by 20%, so what's the point?"

Because by the end of 2 years, if routinely kept at 100%, a battery will often degrade by more than 20%.

For example, every smartwatch I've ever owned, if I left it on charge overnight each night, would have battery life degrade to <2-4 hours in less than 3 years - and the capacity degradation was unpredictable because it would manifest as a huge increase in internal resistance, so in some cases the battery would "brown out" and cause an uncontrolled system shutdown with a voltage that implied 80% SoC.

I have a laptop that does not have a charge termination limit - more than 30% degradation after 3 years.

My DJI batteries are the most egregious example - swelling and failure of 3 batteries in only 9 months of fairly light use, because sometimes I forgot to discharge unused spares between flights (and DJI made it difficult)

Dec 14, 2021permalink

As to "recharging my battery more often" - If left on charge overnight, I only need to charge once per day. However, as stated before, leaving devices on charge overnight often causes more than 20% degradation at the end of 2 years, and on many of my devices, has caused degradation to the point of being useless/dangerous in less than 3.

Dec 14, 2021permalink

Leitz: I read about LiFePo4 in the past. I think one disadvantage it has is the bigger size and lower capacity. But it's great for specific applications, like cold environments.

Dec 14, 2021permalink

"charge to 100%" and "left on charge overnight" are different things. Leaving it overnight you activate trickle charge, thus chemical processes inside battery don't stop. When my phone is charged 100%, I don't leave it overnight (mostly), I just disconnect it from the charger. Don't remember how long I own it but sure more than 3 years and there are no signs of battery degradation.

Dec 14, 2021*permalink

Btw, the swelling (seam-/housing-bursting level) I mentioned (1x Samsung + 2x Xplore tablet) was just by time degradation, not constant trickle charge.
Scary poop on high-end gear.
Perhaps a point of attention for gear testers....is the battery compartment 'explosion-proof', bursting without damage to the housing, like a bunker for fireworks, with roof-hatches to 'vent'....
(or in case of high-tech gear: battery clamps that can give way to pressure from inside....

Dec 14, 2021*permalink

Phones that are left on a charger last longer than ones that are not. Batteries lose capacity over time, but the killer is the number of cycles you use up.

Good batteries have a charge cycle of 500-1000.
Keeping it plugged in will prolong its lifespan more than trickle charging will ever do to decrease it.

My phone is on the charger when not in use. That is 16hours a day that does not accumulate to its recharge cycle.

The other thing that helps is use a slow charger if you want batteries to last.

Dec 14, 2021*permalink

For li-ion batteries, degradation happens with time as well, since the chemical reaction zmsinoky skies when not in use but it still happens. Certain states can cause relapid degradation, such as in the case of 3.7V nominal batteries, draining them below 2.5V degrades them rapidly. For example, a week at 2.3V will easily knock off half of the capacity on subsequent charge cycles. Going slightly above the max voltage listed in the datasheet leads to the same issue the datasheet voltage range used for the advertised capacity when it comes to the charge and discharge curve, will allow for the advertised wear characteristics to be reached. Further changes such as not charging to that level, only offers minimal improvements.
In practice, devices leave a wider margin to be safe, especially with environmental impact.for example, charging to 4.2V at 50F ambient, will lead to a voltage increase when the cell reaches 70f. Beyond that degradation is not linear after a while it will become rapid.

Dec 14, 2021permalink

"Phones that are left on a charger last longer than ones that are not. Batteries lose capacity over time, but the killer is the number of cycles you use up."

Not true. Time spent in the upper 10% of the state of charge regime is extremely stressful on a battery. Time is major contributor to degradation when that time is spent at either of the extremes of the state of charge.

Avoiding that upper 10% will lead to significant improvement in calendar life. Avoiding the upper 20% will lead to even more. Benefits are less once you go below there.

https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries - see the table regarding temperature and charge level. At room temperature (25C), a battery at 100% charge will lose 20% of capacity in only one year. Except that smartphones have a tendency to heat up when in use or on charge.

That also has a table showing that charge cycle lifetime doubles with a 100 mV/cell drop, which is only 10% capacity reduction.

Dec 14, 2021permalink

Li-ion batteries are not trickle charged when full. They cannot handle it at all, and attempting to do it will lead to almost immediate swelling as soon as it reaches its max rated voltage. This is why many devices will not charge a battery that is between 99% and 100% .

Dec 14, 2021permalink

Yup. Nearly every charge control chipset I've seen for a phone, along with the kernel source for every Android phone for which I've read the charging algorithms (which is many, because that's one of the first things OEMs modify and thus routinely has to be forward-ported to a newer kernel when you're doing an AOSP device bringup), has some hysteresis such that once charge terminates, it doesn't resume until voltage drops below a certain threshold. Usually the phones fuel gauge algorithm has some tweaks to hide this behavior and make it appear as 100% even when it's not.

Some Android aftermarket kernel developers implemented early charge termination, it was one of my favorite features (and one that I implemented myself in Galaxy S2 kernels.)

Dec 14, 2021permalink

https://sciencing.com/smartphone-charger-stop-after-its-full-17317.html

@razor - a smartphone is pretty smart in knowing when to charge. My phone is at 100% right now. Charge icon is still on.

Battery usage shows 0% because it is using power from the charger. You guys are confusing a battery used in a phone to a regular cell that you use in a electronic device. Unless you turn your phone off, the battery is getting drained if there is no other power source. Keeping it on the charger reduces this battery cycling.

Just like a laptop that is always plugged in lasts longer than one that is never.

Dec 14, 2021permalink

Maybe I used "trickle charge" incorrectly. What I really meant – yes, when the battery is full, charger stops charging. But battery does not stay 100% even if there is no load, it becomes 99%, 98% etc. So if charger is connected, it immediately starts charging again. Then battery becomes full again and the charger stops. Then battery again becomes 99% etc. So charging process does repeat time to time while the charger is connected.

The number of cycles is not how many times you connected charger or started charging. It's how many times you charged the battery to its full capacity. It's additive. I.e. one 100% charge is one cycle, and 10 times by 10% charge is also one cycle. Roughly.

Dec 14, 2021permalink

TBLF

I guess 10% might be ok if you're living on the edge...

Now if Samsung could just get my Galaxy Watch to run as long as my wife's Fitbit, then I'd be truly impressed! (2 days vs/2 weeks!)

Dec 13, 2021permalink

mxx

I've got a Casio watch that's been running for about 20 years on the same battery.

Dec 15, 2021permalink

TBLF

OK mxx, that reply gets 2 thumbs up and a chuckle.
Point taken and thanks for the laugh!

Dec 16, 2021permalink

Caleido

Oh so the battery consumption hit caused by 5G compared to 3G-4G will now be reduced from 35% to 25%. Hurray.

Dec 13, 2021permalink

spider-mario

Would be good to know whether it affects lifespan in any way. 10% more capacity when brand new is nice, but not if it declines faster with age.

Dec 13, 2021permalink

Gesture

I'll take 10 percent LESS capacity and 30 percent MORE safety.

Dec 13, 2021permalink

Fun fact - a manufacturer implementing a charge control algorithm that gives you the option to shut off at 90% pretty much gives you exactly this with existing tech.

Spending time at the upper 10% of the state of charge range is REALLY bad for a battery, especially if it gets warm.

Dec 13, 2021*permalink

do you feel unsafe with current batteries?

Dec 13, 2021permalink

Most consumer electronics do not charge a battery to it's true 100% point, they all pretty much leave a few percentage points of capacity unused for safety and longevity. For example, it is common to see a rechargeable cell on wireless earbuds with an end of cycle 4.35V and a draw of 0.05mA, but they will often be charged to 4.2, and a draw of 25mA.

Dec 13, 2021permalink

Leitz

The safe alternative to Lithium-ion is LiFePo4 but is less energy dense.

Dec 14, 2021permalink

@dr.noise - I've had multiple batteries in products that didn't support early charge termination swell, and a swollen battery is unsafe.

I've had to throw away two smartwatches because the battery degraded so severely, and had 3 DJI Phantom batteries swell in less than a year because they required a proprietary charge (no early charge termination, no controlled discharge function). My Yuneec Typhoon batteries, which I've never charged beyond 4.1 volts/cell (normal charge termination for them is 4.2) are showing almost no degradation after 5 years.

Dec 14, 2021*permalink

For drones, they often charge the batteries to their true 100%, and drain them down as close to minimum allowed in the datasheet. Since flight time is a major selling point, there is a push to deep cycle the battery as much as possible without bringing the cells down to a critical voltage. This also means that a cell that is rated for 800 cycles, may end up only delivering 200 cycles. The same happens with battery powered lawn mowers.

Dec 14, 2021permalink

Yup, in general, lots of companies push batteries to their limits to get every single minute of per-charge life for a new-in-box product on their spec sheets.

That destroys the long-term usability of the product. Reducing my Yuneec's charge term to 4.1 volts/cell lost me 10% flight time per pack for only a few months. Past the first 6-9 months - I got more flight time per charge because I'd retained capacity, and VASTLY more total flight time per battery. Enough that, unlike my Phantom, I never had to buy a second pair of batteries of which one of THEM failed in less than a year.

Edit: @Razor512 - nearly every consumer product I've ever seen goes all the way to the limits of the chemistry. 4.2 volts/cell, or for the newer HV chemistry seen in many mobile phones starting around 6-8 years ago, 4.35. For Android phones, this is usually easily determined by reading the kernel source.

Dec 14, 2021*permalink

Gesture

Entropy512 Would be great if you offered an article on this to DPReview?

Dec 14, 2021permalink

@Entropy512 For many modern cells, the nominal voltages as well as fully charged voltages have changed. In the past, it was common for batteries to be designed for a max of 4.2V and a full discharge down to 2.7V, with a safety cutoff at 2.6V, and a protection circuit kicking in at 2.4V where the cell would no longer charge unless you bypass the protection circuit.

The standard now are cells with a nominal voltage of 3.87V and a full charge 4.45V, with typically a safety cutoff in the 4.55-4.6V range, at which point, the protection circuit will trip. Most smartphones will typically give up around 0.3-0.4Wh of capacity on a 15-16Wh by charging to a slightly lower voltage.
This is especially common with smartphone batteries. Different companies have different voltage ranges.
PS, some devices will further limit charge level if the battery will ever reach 60C while at a "full" charge.

Dec 15, 2021permalink

@gesture - don't need to - https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries

Unless you mean a history of charging control in smartphone kernel source? Be warned I'm a bit rusty, it's been a while since I did AOSP kernel maintenance work.

Dec 15, 2021permalink

Wanted to also add that a more accurate way to measure the effective cycle life of a battery, is to measure accumulated output of the cycles that charge the battery to full, and do the complete test, e.g., 500 cycles, then for partial cycles, run those cycles until you natch the accumulated output of the full cycles test run. Then you do a full 100% on each test cell, and deep cycle them to measure capacity.

Most tests treat things like 80 to 90% cycles the same as 100% cycles, which is inaccurate.

Dec 15, 2021*permalink

Gesture

Thanks. Good thread.

Dec 15, 2021permalink

Mortal Lion

While 10% doesn’t sound like much it also isn't much

Dec 13, 2021permalink

Franz Weber

It is more than 9% and much more than 4%

Dec 13, 2021permalink

But slightly less than 11%, while at the same time significantly less than 15%.
Seems we can settle on it being a compromise?

Dec 13, 2021permalink

Kerensky97

But what is it in APS-C equivalence?

Dec 14, 2021permalink

M4NH4CK

I would be more concerned with the 3D pop due to all that added silicon... Wouldn't want my batteries to have high dynamic range.

Dec 14, 2021permalink