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How to prolong lithium based batteries

batteryuniversity.com

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Re: How to prolong lithium based batteries

#31

Post by 1970-01-01 »

speedgoose wrote: post #8

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.

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.

Re: How to prolong lithium based batteries

#33

Post by SubiculumCode »

izzydata wrote: post #29
speedgoose wrote: post #8

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?

Re: How to prolong lithium based batteries

#34

Post by 1970-01-01 »

SubiculumCode wrote: post #32

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.

Re: How to prolong lithium based batteries

#35

Post by radomir_cernoch »

izzydata wrote: post #29
speedgoose wrote: post #8

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.

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.

Re: How to prolong lithium based batteries

#36

Post by sitkack »

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...

Re: How to prolong lithium based batteries

#37

Post by Rygian »

SubiculumCode wrote: post #32

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.

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

Re: How to prolong lithium based batteries

#38

Post by sitkack »

_yb2s wrote: post #19

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…

https://chargie.org/

Re: How to prolong lithium based batteries

#39

Post by sitkack »

SubiculumCode wrote: post #32

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.

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

Re: How to prolong lithium based batteries

#40

Post by crazygringo »

ein0p wrote: post #27
crazygringo wrote: post #18

Earlier quoted context omitted.

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.

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

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