GodOfPlutonium

GodOfPlutonium t1_jay78a5 wrote

check your phone settings, some phones have options now to stop charging early, but you have to enable it. IDK about most phones and its not automatic. In general not charging to 100% is good, but there is no point in unplugging it if its actually full, as then the phone electronics are just running off of wall power

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GodOfPlutonium t1_jauxq7j wrote

this is patently ridiculous. In your original comment you you replied to me saying not to deep discharge with

> but you can discharge as low as you want.

Only now have you shifted your argent to '25% is ok'.

> 500 cycles to 70% if you discharge 100% every time, not your 500 cycles to 80% claim.

I used 500 to 80% instead of 300 to 70% because the better number for standard discharge is better for your position not mine lmao, if you try to recalculate with the worse standard numbers, it just increases the amount that avoiding full discharge saves.

The point being It does not prove anything about discharging to 0%. If you want to tell people not to discharge below 25% instead of below 40% that is one thing, but you have explicitly claimed multiple times that you can discharge as far as you want , which as I have previously explained is demonstrably false using your own data.

> As for the extra protection phones have.. https://en.wikipedia.org/wiki/Cutoff_voltage which cites http://www.ibt-power.com/Battery_packs/Li_Ion/Lithium_ion_tech.html as it's source. This shows a cutoff of 3v, although it also says manufacturers set this limit themselves which is kind of obvious. I doubt they set the limit just above what kills the phone, otherwise we'd hear of phones being replaced every few months instead of every 2 years as normal. I also never did claim phones have extra protection, just that they have a BMS that protects them from full discharges. Again with the strawman arguments...

There is no strawman argument, you explcitly stated

>super well protected against this type of damage and often stop battery draw well before the battery actually loses all charge.

The term "super well" implies additional protection beyond what is normal. Furthermore you have again linked to a source disproves your own argument. Your entire argument is predicated on the idea that the low voltage protection will shut down the battery with a significant buffer before 0 charge. The graph in your own second link that at a 0.2c discharge rate (which translates to a 5 hour battery life, so in a phone itd be even lower discharge rate), there is 3% energy left at a 3v cutoff. This literally proves what I said in the previous comment

> If you actually go look at a lithium ion discharge graph, as current draw decreases, the voltage curve shifts upward and rightwards. This means that as discharge reduces , the state of charge that a voltage represents is lower and lower. Phones are a low power, high energy application, which means that even if you set the lvp to 3v, a full 0.5v over 2.5v, it represents very little remaining energy.

Furthermore,

> Lots of people believe a lot of things, to argue otherwise is nonsensical

In this very thread there are plenty of people arguing that memory effect needs to be avoided, and 0 people arguing that it is as you put it " catastrophically damaging", only more wear. Even battery myth articles commonly address the memory effect idea, not whatever youre saying.

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GodOfPlutonium t1_jaus3p0 wrote

> I never said that discharging your battery causes it to explode.

You never claimed that it actually would, you claimed that other people claimed it would, here

> is dispel this myth that it's catastrophically damaging to your phone battery to discharge it to 0%.

Once again this belief does not exist. Furthermore

> You can pretty safely discharge your battery well below the 40% level and still expect amazing longevity, you're really making the very most gains in your battery by not charging to 100%. The "Don't discharge below this level" gang is talking about miniscule battery life gains, and here I am trying to promote massive multi-year gains.

Once again your own source doesnt actually prove your point and in part argues against it. Since as you note, table 6 does not test discharge to 0%, it is impossible to actually use it to determine if not charging fully or not discharging fully is better if you had to decide between only doing one. In order to do so would require testing 75-0% in order to compare against 100%-25%

However it does completely and definitively disprove your claim that

> "Don't discharge below this level" gang is talking about miniscule battery life gains

As previously stated the typical 100%-0% lifespan to 80% of original capacity is 500 cycles. Per table 6, the 100%-25% lifespan to 80% was 3500 cycles while the 100-40% lifespan was 5000 cycles. This translates to a 7 times and 10 times extension in battery life respectively.

This is exactly the massive multi year gain that you claimed it did not bring. Furthermore it suggests that the reason that limited maximum charge was not tested in the first place is since it was obviously the first step one would take to extend battery life.

> however phone batteries are super well protected against this type of damage and often stop battery draw well before the battery actually loses all charge.

If you actually go look at a lithium ion discharge graph, as current draw decreases, the voltage curve shifts upward and rightwards. This means that as discharge reduces , the state of charge that a voltage represents is lower and lower. Phones are a low power, high energy application, which means that even if you set the lvp to 3v, a full 0.5v over 2.5v, it represents very little remaining energy. And once again, I did initially ask for a source that showed that phones have some extra protection that normal batteries dont have, which you have not posted.

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GodOfPlutonium t1_jaulq2b wrote

> It's not something that all lithium ion batteries have, and if you used them in something other than phones

My talking about charging ~overcharged~~ overdischarged cells should clue you in that i have experience handling lithium cells. Yes you can buy raw lithium cells that dont have an attached pcm/bms. The point is that it is standard to use them with one. The only use I am aware of that regularly doesnt use one is RC quads where they use a single lvp for the entire pack, necessitating the use of balance chargers and often fireproof bags

> dispel this myth that it's catastrophically damaging to your phone battery to discharge it to 0%.

That myth straight up does not exist. There is literally no common belief discharging your phone to zero will cause to explode. The exact opposite belief, that you need to discharge your phone to 0% regularly to prevent memory effect like you did with NiMH cells, is far more common.

Everyone saying that you should avoid discharging your battery below 40% or 30% is advising to do so in order to prolong battery lifespan. This is something that you explcitly argued against in your original comment, and is what I took exception to:

> , but you can discharge as low as you want.

Yet your own battery university link that you edited in proves that in table 2 and disproves your statment.

> It's not. Your phone turns off at 10% capacity at the very least

I literally said as much before you did

> the low voltage protection is set to a high voltage such as 2.7v or 3v instead of the actual minimum voltage of 2.5v. That doesnt protect you nearly as much as it sounds like because the voltage curve is not linear, it flattens out at 3.7v for a while, so 3.3v is already down to 15% left or so

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GodOfPlutonium t1_jaujcz7 wrote

All lithium batteries use protection for undervoltage (aka low voltage protection), either built into cell / pack or built into the device. PCM/BMS is standard, not some special thing that phones have.

You just read that 'technically empty doesn't mean there is no energy left' , because its physically possible to drain a cell down to 0v while protection stops at 2.7v or whatever. Thats not made to add more lifespan than normal, thats to prevent the battery from exploding after you discharge it below 2.5v and then try to charge it. Any cell that has gone under 2.5v should be considered destroyed and not used. It may be possible to revive the cell by charging it up slowly while monitoring heat but is almost never worth it since even if doesn't catch fire it is permanently damaged and will have poor performance. The 'do not do low discharge' advice is for the last part inside the allowed range

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GodOfPlutonium t1_jauglo0 wrote

Do you have some sort of actual source for this? Becuase what " stop battery draw well before the battery actually loses all charge " usually means is that the low voltage protection is set to a high voltage such as 2.7v or 3v instead of the actual minimum voltage of 2.5v. That doesnt protect you nearly as much as it sounds like because the voltage curve is not linear, it flattens out at 3.7v for a while, so 3.3v is already down to 15% left or so

edit: also typical lithium ion lifespan is 500 cycles to 80%

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GodOfPlutonium t1_jau1e7w wrote

> It can actually be bad for your phone battery to charge it too often or too soon or even too full. Best practice is to go down to critical (10% or so) then back up to 80%.

The future is now old man. What you said mightve been true for nimh batteries but is terrible advice for anything with a lithium ion battery. Best thing you can do for a lithium ion battery is to not go below 40% or 30%. Second best thing is to not go above 80%

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