Quote from: _MT_ on April 20, 2020, 11:57:41
You're right that I don't know what "Battery Idle Priority" is. I tried looking it up but Google unusually found only one result - your post under this article. Not a single other mention. And no, thank you, I'm not going to root my phone. You wrote that "the charging input current can bypass the battery totally and only powers the device's internal components directly." I never looked at the boards or experimented with it, but that's how a laptop should behave and always appeared to me to behave that way. It should work like that as Li-ion cells generally can't be trickle charged. At some point, there has to be a hard cut-off. As I understand it, charging circuits for Li-ion cells typically have a timer as a last resort limit to prevent accidental overcharging (it's simple and more fool proof than integrating charge from current; but again, I won't claim to know all the charging solutions on the market because I don't). Because it's tricky to measure state of charge at high states. Once the battery was charged, laptop went into AC powered mode and stayed there. I have never observed any cycling between charging and discharging. To me, that would be really stupid. So stupid it's unthinkable. Why would anyone do that? As I said, I never looked into how they do it. Which chips they use, what the datasheets say. And at least in the "dumb phone" days, I would have expected the exact same behaviour. And again, I don't recall a single phone that would show cycling. At idle, no phone call. With a phone call, I believe it could cycle (meaning cell would discharge during the call and top up after the call). But again, I never verified. I've never tried connecting a cell simulator instead of the actual cell to monitor what's going on.
While it's not my field, I read a fair share of white-papers from companies like Saft. Apparently, I know enough for them to sell me cells which are restricted and not available to the public. I haven't yet burned down my house. Yes, when I wrote that it should take days, it was an understatement. Call it laziness. I never needed that number (I know how much I should charge them for storage and how often to check them, that's all I need) and was more concerned about not overselling. Point was that charging won't restart in a hurry. If you actually unplug the laptop from time to time and use it, it should charge just once.
I call that honesty. It always appeared to work that way and I never felt the need to check. I have much more interesting projects to spend time on than digging around a laptop charging circuit. If I ever noticed the cycling you speak of, I would have investigated. As I wrote, to me, the notion is incredibly stupid and I would find it unbelievable that someone did it, motivating me to investigate. Never noticed, never investigated. One difference between phones and laptops was that it was pretty common for laptops to spend significant time on a charger. With phones, however, you'd generally disconnect them once they were recharged (at the earliest opportunity). So, to design a laptop the way you suggest would be really stupid. A phone, not so much. And while I never investigated, over the years, I left quite a few laptops sitting on a charger. Sometimes for months at a time (of course, with the battery kept at a lower state of charge). Never noticed the batteries suffering. Constant cycling would have surely shown.
How do you know it's "EXACTLY" 60 %? Because the phone told you? Don't make me laugh. If you know so much, you know the difficulties and uncertainties.
Quote from: Astar on April 19, 2020, 21:32:09You're right that I don't know what "Battery Idle Priority" is. I tried looking it up but Google unusually found only one result - your post under this article. Not a single other mention. And no, thank you, I'm not going to root my phone. You wrote that "the charging input current can bypass the battery totally and only powers the device's internal components directly." I never looked at the boards or experimented with it, but that's how a laptop should behave and always appeared to me to behave that way. It should work like that as Li-ion cells generally can't be trickle charged. At some point, there has to be a hard cut-off. As I understand it, charging circuits for Li-ion cells typically have a timer as a last resort limit to prevent accidental overcharging (it's simple and more fool proof than integrating charge from current; but again, I won't claim to know all the charging solutions on the market because I don't). Because it's tricky to measure state of charge at high states. Once the battery was charged, laptop went into AC powered mode and stayed there. I have never observed any cycling between charging and discharging. To me, that would be really stupid. So stupid it's unthinkable. Why would anyone do that? As I said, I never looked into how they do it. Which chips they use, what the datasheets say. And at least in the "dumb phone" days, I would have expected the exact same behaviour. And again, I don't recall a single phone that would show cycling. At idle, no phone call. With a phone call, I believe it could cycle (meaning cell would discharge during the call and top up after the call). But again, I never verified. I've never tried connecting a cell simulator instead of the actual cell to monitor what's going on.
I don't know the point of your post. I don't think you understand what Battery Idle Priority means either. Go root your Android before you comment. It actually requires your Android kernel to support it and by extension the charging circuit.
I don't think you even understand Li-ion battery chemistry. The rate of self-discharge is very low compared to other chemistries. Again, I don't think you even understand how it works - my Android phone battery level stays at 60% EXACTLY when I prioritize battery idle. Without enabling the mode, it does the same thing as the laptop, which is charge up to 60%, discharge to 59% and then charges up to 60% ad nauseum. That means you are eating up charging cycles and wearing out the battery still.
Then again... if you can open your comment by saying "I have never verified ... " then you truly don't know what you are saying.
Quote from: _MT_ on April 19, 2020, 12:07:26
I have never verified but this is how any laptop should work. At least with traditional charging (and I don't see any reason why USB charging should be different). The second threshold is there so that the charger doesn't have to maintain precisely that level. Because cells slowly discharge on their own, without any load. First of all, it can be tricky to precisely determine the state of charge. And you don't want to restart charging all the time. So they leave a small window of a few percent (I don't think I have ever seen less than two; or more than five). It should take days for it to lose a couple percent. This way, you have a guarantee that there will always be at least 97 % or whatever it is.
The main reason to remove battery is to protect it from heat. Charging limits are great in that they allow you to set and forget. Rather than having to stop the charging manually (at least I believe I could simply do it from Windows - I don't think I ever had to). Awesome thing back in the day when docking stations were popular.
I would love such a manual limit in a phone. Especially in phones with inductive charging. Because I can keep in on a mat most of the time. It would allow me to forget about it without unnecessarily damaging the cell. At least some phones have "intelligent" charging which should recognize such behaviour and limit charging appropriately. I guess it's better for most people, I would prefer a dumb limit I can trust in (rather than trusting that a piece of silicon can figure out what I'm trying to do).
Quote from: Astar on April 18, 2020, 23:52:04I have never verified but this is how any laptop should work. At least with traditional charging (and I don't see any reason why USB charging should be different). The second threshold is there so that the charger doesn't have to maintain precisely that level. Because cells slowly discharge on their own, without any load. First of all, it can be tricky to precisely determine the state of charge. And you don't want to restart charging all the time. So they leave a small window of a few percent (I don't think I have ever seen less than two; or more than five). It should take days for it to lose a couple percent. This way, you have a guarantee that there will always be at least 97 % or whatever it is.
I just wish ASUS and all laptop manufacturers can implement what Android allows (with root) - a Battery Idle Priority function (with ACCA) - where the charging input current can bypass the battery totally and only powers the device's internal components directly. This is a godsend on Android where my smartphone is connected to the USB for most of the working day and I know the battery isn't being touched at all. Also works great when I am using USB tethering as I know the laptop battery isn't being drained by the requirements of Android phone battery charging.
Quote from: Astar on April 18, 2020, 23:52:04
CrApple... late to the game as ALWAYS!
ASUS laptops have had this feature for a few years now.
Its called "ASUS Battery Health Charging" and is just a simple pre-installed software tool (or you can download it separately if you don't want all the other ASUS software) with 3 checkboxes - 100% (Full Capacity Mode), 80% (Balanced Mode) or 60% (Maximum Lifespan Mode).
It just stops charging at any of the 3 levels you select and only resumes charging at 78% or 58%.
I just wish ASUS and all laptop manufacturers can implement what Android allows (with root) - a Battery Idle Priority function (with ACCA) - where the charging input current can bypass the battery totally and only powers the device's internal components directly. This is a godsend on Android where my smartphone is connected to the USB for most of the working day and I know the battery isn't being touched at all. Also works great when I am using USB tethering as I know the laptop battery isn't being drained by the requirements of Android phone battery charging.
Quote from: jeremy on April 18, 2020, 19:41:31
I've been running something similar with every laptop I've had since the early 2010s, with my Sony Vaio S. The one time I haven't, was on the first battery of my Dell Latitude E5450. The battery lasted about 15 months before it would randomly cut power at 10-30%. Its replacement, which I used the battery threshold limit on (80% for that one), has lasted for at least 4 years, now. without the same failures. For me, it's a hard pass on any laptop without such a feature. I do appreciate that on Dells, the limit may be set in the BIOS/UEFI, so I don't have to install any application to actually change the thresholds.