7 ms·

Battery power management for power users (2023)

32 points by laserstrahl 3y ago

user_7832 3y ago
> If you want to keep your phone’s battery health in the best possible condition it possibly could be in, you must use the Google charger and cable and keep them all plugged in around the clock. Correct me if I'm wrong but the best state of charge for long term storage (not use) is around 60%. While modern Apple devices (and probably Pixels too?) cap their charge at 80% if permanently plugged in, a. this indicates that 80% is better than 100%; and b. this partially matches with what I've heard of users with permanently plugged in devices/iPads in meeting rooms ending up with swollen batteries. Heck, my Framework has an option in the bios to limit max charge, and recommends that to be used if kept plugged in very often. There is the counter-fact that if your system doesn't support a lower state of max charge, you may need to unplug the device and use it, ideally draining it from 80%-40% and back (as per Apple). However, I rarely find swollen batteries in phones used in everyday life but have heard about it in the cases of permanently plugged devices. I think I'd rather just use the charge cycles of the device. > Popular advice going around has been to slow charge with an older and slower charger rated for less current, to reduce the heat on the battery. > If the battery’s getting too hot or the battery’s own conditions aren’t ideal for fast charging, the phone will slow down to preserve the health of the battery. I'm sorry but this doesn't make too much sense. Heat is generally acknowledged as bad for batteries. Saying "the system will throttle charging if it gets too warm" doesn't mean it's necessarily good to hit that throttle temp in the first place. If 25 degrees is good, 30 degrees is not bad and 40 degrees is bad, it's great that it's not going to hit 40, but if I can restrict it to 25 that's even better. Additionally, anecdotally the possible cause of "wireless chargers degrade batteries" is due to thermal degradation (again, what I saw probably on reddit). I have a 5w ikea wireless charger. It takes time to charge my Pixel 5, but my phone doesn't get too hot. I'll be very happy to hear from the more experienced members of their views.
- user_7832 3y ago
  (I would greatly appreciate it if some clarification can be provided on what I said wrong, as I regularly deal with 21700 li-ion cells and likely will deal with more, and I’d like to do so safely. I’m assuming I was downvoted because I said something wrong, which in the world of lithium batteries, can be quite dangerous.)
  - deleted 3y ago
    [deleted]
- Domenic_S 3y ago
  >> If you want to keep your phone’s battery health in the best possible condition it possibly could be in, you must use the Google charger and cable and keep them all plugged in around the clock. > Correct me if I'm wrong but the best state of charge for long term storage (not use) is around 60%. Your reaction is a non-sequitur to the author's point; they were being sassy by saying if you want optimal battery life, plug in and let the device manage voltage/battery health forever. > this indicates that 80% is better than 100% Better for what? 50% is better for long-term disconnected storage -- actually, voltage is better than % and for storage you're aiming for 3.7v/cell (which is roughly 40-50%) which is where the discharge properties slow almost to a halt. 80% is the kind of standard "I'm not discharging this charge immediately"-recommended state (see: EV charging recommendations). What the author mentioned in passing and didn't really explain is overprovisioning, which is where the device reports e.g. 100% charge, when the cells are really e.g. 92% charged, which some devices do to maintain battery health. So depending on your device and its configuration, trying to keep charge capped at 80% might in reality be keeping it much lower than you intended. Anyway, the point of the article is for batteries with good battery management systems -- like modern phones -- it is better to not try and micromanage SoC and let the system do its thing. Those of us that have lots of naked cells should be doing that micro for those cells, but when built into a device with proper management there's no need and it could hurt more than it helps.
  - yjftsjthsd-h 3y ago
    > Your reaction is a non-sequitur to the author's point; they were being sassy by saying if you want optimal battery life, plug in and let the device manage voltage/battery health forever. I don't think that's a non sequitur; the author is wrong. Leaving the device plugged in won't give you optimal battery life, it will at best simply avoid it mattering. The firmware can reserve room and say it's at 100% when it's physically 90%, but that's still going to degrade the cells faster than 80% or 60%.
    - Domenic_S 3y ago
      The fact is we (you and I) don't know what the Android phone's behavior is when plugged in 24/7 (note the author is a community mod for an Android-compatible OS). The UI can/does lie, and it's probably different from model to model, so at best we can say we're not sure if he's right or not. Technically using DC power instead of battery is best for battery health (dis/charge cycles are worse for battery health) but like I said before, it's just a snarky suggestion on his part.
easygenes 3y ago
The article suggests not charging your phone to 80% and unplugging, but doesn’t cover the recent iOS setting which allows capping your charge to 80%. That’s what I do and it offers best of both worlds.
ohazi 3y ago
No, this is bad advice. Yes, battery management software has gotten better, but you still can't get around physics. Keeping lithium polymer cells at close to 4.2V per cell for prolonged periods of time will degrade them quickly, regardless of any clever "maintenance mode" hacks that make the cell dance around the top 5% of it's capacity. But also, never charging past 80% will confuse the charge controller and start giving you incorrect percentages if it's not expecting you to do that. Charge to 80% most days, charge to 100% occasionally, avoid discharging beyond 10 or 15%.
- Terr_ 3y ago
  Maybe I'm just on a nostalgia kick today, but it's funny to think of when I was first introduced to that caution in the form of cyborg video- game dialogue. > JAIME REYES: What kind of pain? > WALTON SIMONS: Behind the eyes. A sharp burning. Almost electrical. > JAIME REYES: How's your bioelectric level? > WALTON SIMONS: It's always at a hundred percent. I like to stay prepared. > JAIME REYES: That's probably it right there. Free radicals. You should charge your systems only when they've been significantly drained. > WALTON SIMONS: I wasn't informed of that. > JAIME REYES: It's a lot like an electric razor. If you leave it plugged in all the time, the battery loses its zero point. Just watch your levels. > WALTON SIMONS: Interesting. Thanks, Doctor. -- Deus Ex (2000)
- ploxiln 3y ago
  > the GrapheneOS golden rule applies: don’t try to be a ‘power user.’ The devices GrapheneOS supports are thoroughly modern and will manage their own battery health automatically, far better than you ever could manually So this advise is distorted by an apparent hate for "power users". It's strange to suggest that modern embedded hardware is perfect. But more importantly, there's a conflict between the longest battery life your product can offer in initial reviews, and longevity years later. And while it's true that "fast" charging isn't necessarily bad at all, there is similarly a conflict between offering the fastest charging for reviews/comparisons, and keeping the temperature optimal for longevity. So for their "power users bad" philosophy they should have just said "plug it in whenever you want, it'll be perfectly fine". To say you could get the best possible battery longevity by keeping the phone plugged in at all times (with the original charger?!) is absurd, especially combined with the fact that apparently grapheneOS doesn't have the usage-pattern-learning feature to keep charge at 80% until just before you unplug each day ...
yjftsjthsd-h 3y ago
> They were designed for certain assumptions taking into account certain limitations, and taking into account what most users tend to do. ...and that right there is why most[0] of this article is bad advice. It's not about being a "power user"[1], it's that I know more than the machine. I know when I'm going to want battery power available and when I won't. I know when I need to charge as fast as possible and when trickle charging is an option. For bonus points, Google's been trying to let the phone figure these things out... so then these folks apparently rip that out, too, lest the poor firmware get any help knowing what to do. [0] The bit about not discharging to zero is good; I don't miss NiCd. [1] Side note: "the GrapheneOS golden rule applies: don’t try to be a ‘power user.’" is... interesting advice for an OS that is almost by definition only used by power users; I would love to hear a definition of the term that somehow doesn't include people who replace their phone's OS.
ziotom78 3y ago
This is in stark contrast with what has been said elsewhere: https://electronics.stackexchange.com/a/623375 https://electronics.stackexchange.com/a/623375

32 points by laserstrahl 3y ago

> If you want to keep your phone’s battery health in the best possible condition it possibly could be in, you must use the Google charger and cable and keep them all plugged in around the clock. Correct me if I'm wrong but the best state of charge for long term storage (not use) is around 60%. While modern Apple devices (and probably Pixels too?) cap their charge at 80% if permanently plugged in, a. this indicates that 80% is better than 100%; and b. this partially matches with what I've heard of users with permanently plugged in devices/iPads in meeting rooms ending up with swollen batteries. Heck, my Framework has an option in the bios to limit max charge, and recommends that to be used if kept plugged in very often. There is the counter-fact that if your system doesn't support a lower state of max charge, you may need to unplug the device and use it, ideally draining it from 80%-40% and back (as per Apple). However, I rarely find swollen batteries in phones used in everyday life but have heard about it in the cases of permanently plugged devices. I think I'd rather just use the charge cycles of the device. > Popular advice going around has been to slow charge with an older and slower charger rated for less current, to reduce the heat on the battery. > If the battery’s getting too hot or the battery’s own conditions aren’t ideal for fast charging, the phone will slow down to preserve the health of the battery. I'm sorry but this doesn't make too much sense. Heat is generally acknowledged as bad for batteries. Saying "the system will throttle charging if it gets too warm" doesn't mean it's necessarily good to hit that throttle temp in the first place. If 25 degrees is good, 30 degrees is not bad and 40 degrees is bad, it's great that it's not going to hit 40, but if I can restrict it to 25 that's even better. Additionally, anecdotally the possible cause of "wireless chargers degrade batteries" is due to thermal degradation (again, what I saw probably on reddit). I have a 5w ikea wireless charger. It takes time to charge my Pixel 5, but my phone doesn't get too hot. I'll be very happy to hear from the more experienced members of their views.

user_7832 3y ago
(I would greatly appreciate it if some clarification can be provided on what I said wrong, as I regularly deal with 21700 li-ion cells and likely will deal with more, and I’d like to do so safely. I’m assuming I was downvoted because I said something wrong, which in the world of lithium batteries, can be quite dangerous.)
- deleted 3y ago
  [deleted]
Domenic_S 3y ago
>> If you want to keep your phone’s battery health in the best possible condition it possibly could be in, you must use the Google charger and cable and keep them all plugged in around the clock. > Correct me if I'm wrong but the best state of charge for long term storage (not use) is around 60%. Your reaction is a non-sequitur to the author's point; they were being sassy by saying if you want optimal battery life, plug in and let the device manage voltage/battery health forever. > this indicates that 80% is better than 100% Better for what? 50% is better for long-term disconnected storage -- actually, voltage is better than % and for storage you're aiming for 3.7v/cell (which is roughly 40-50%) which is where the discharge properties slow almost to a halt. 80% is the kind of standard "I'm not discharging this charge immediately"-recommended state (see: EV charging recommendations). What the author mentioned in passing and didn't really explain is overprovisioning, which is where the device reports e.g. 100% charge, when the cells are really e.g. 92% charged, which some devices do to maintain battery health. So depending on your device and its configuration, trying to keep charge capped at 80% might in reality be keeping it much lower than you intended. Anyway, the point of the article is for batteries with good battery management systems -- like modern phones -- it is better to not try and micromanage SoC and let the system do its thing. Those of us that have lots of naked cells should be doing that micro for those cells, but when built into a device with proper management there's no need and it could hurt more than it helps.
- yjftsjthsd-h 3y ago
  > Your reaction is a non-sequitur to the author's point; they were being sassy by saying if you want optimal battery life, plug in and let the device manage voltage/battery health forever. I don't think that's a non sequitur; the author is wrong. Leaving the device plugged in won't give you optimal battery life, it will at best simply avoid it mattering. The firmware can reserve room and say it's at 100% when it's physically 90%, but that's still going to degrade the cells faster than 80% or 60%.
  - Domenic_S 3y ago
    The fact is we (you and I) don't know what the Android phone's behavior is when plugged in 24/7 (note the author is a community mod for an Android-compatible OS). The UI can/does lie, and it's probably different from model to model, so at best we can say we're not sure if he's right or not. Technically using DC power instead of battery is best for battery health (dis/charge cycles are worse for battery health) but like I said before, it's just a snarky suggestion on his part.

easygenes 3y ago

The article suggests not charging your phone to 80% and unplugging, but doesn’t cover the recent iOS setting which allows capping your charge to 80%. That’s what I do and it offers best of both worlds.

ohazi 3y ago

No, this is bad advice. Yes, battery management software has gotten better, but you still can't get around physics. Keeping lithium polymer cells at close to 4.2V per cell for prolonged periods of time will degrade them quickly, regardless of any clever "maintenance mode" hacks that make the cell dance around the top 5% of it's capacity. But also, never charging past 80% will confuse the charge controller and start giving you incorrect percentages if it's not expecting you to do that. Charge to 80% most days, charge to 100% occasionally, avoid discharging beyond 10 or 15%.

Terr_ 3y ago
Maybe I'm just on a nostalgia kick today, but it's funny to think of when I was first introduced to that caution in the form of cyborg video- game dialogue. > JAIME REYES: What kind of pain? > WALTON SIMONS: Behind the eyes. A sharp burning. Almost electrical. > JAIME REYES: How's your bioelectric level? > WALTON SIMONS: It's always at a hundred percent. I like to stay prepared. > JAIME REYES: That's probably it right there. Free radicals. You should charge your systems only when they've been significantly drained. > WALTON SIMONS: I wasn't informed of that. > JAIME REYES: It's a lot like an electric razor. If you leave it plugged in all the time, the battery loses its zero point. Just watch your levels. > WALTON SIMONS: Interesting. Thanks, Doctor. -- Deus Ex (2000)
ploxiln 3y ago
> the GrapheneOS golden rule applies: don’t try to be a ‘power user.’ The devices GrapheneOS supports are thoroughly modern and will manage their own battery health automatically, far better than you ever could manually So this advise is distorted by an apparent hate for "power users". It's strange to suggest that modern embedded hardware is perfect. But more importantly, there's a conflict between the longest battery life your product can offer in initial reviews, and longevity years later. And while it's true that "fast" charging isn't necessarily bad at all, there is similarly a conflict between offering the fastest charging for reviews/comparisons, and keeping the temperature optimal for longevity. So for their "power users bad" philosophy they should have just said "plug it in whenever you want, it'll be perfectly fine". To say you could get the best possible battery longevity by keeping the phone plugged in at all times (with the original charger?!) is absurd, especially combined with the fact that apparently grapheneOS doesn't have the usage-pattern-learning feature to keep charge at 80% until just before you unplug each day ...

yjftsjthsd-h 3y ago

> They were designed for certain assumptions taking into account certain limitations, and taking into account what most users tend to do. ...and that right there is why most[0] of this article is bad advice. It's not about being a "power user"[1], it's that I know more than the machine. I know when I'm going to want battery power available and when I won't. I know when I need to charge as fast as possible and when trickle charging is an option. For bonus points, Google's been trying to let the phone figure these things out... so then these folks apparently rip that out, too, lest the poor firmware get any help knowing what to do. [0] The bit about not discharging to zero is good; I don't miss NiCd. [1] Side note: "the GrapheneOS golden rule applies: don’t try to be a ‘power user.’" is... interesting advice for an OS that is almost by definition only used by power users; I would love to hear a definition of the term that somehow doesn't include people who replace their phone's OS.

ziotom78 3y ago

This is in stark contrast with what has been said elsewhere: https://electronics.stackexchange.com/a/623375 https://electronics.stackexchange.com/a/623375