8 ms·

"New firmware-based battery charge control, which offers fixed a 75%/80% threshold setting. To use this, you need to update your system firmware to at least ver

"New firmware-based battery charge control, which offers fixed a 75%/80% threshold setting. To use this, you need to update your system firmware to at least version 13.0, which you can do by simply updating your macOS partition to at least that version or newer. This new charge control method also works in sleep mode." This is interesting, am I correct in thinking this a feature implemented by Apple and now supported by the Asahi team? Does that mean that macOS supports this charge control feature? I really hope Apple brings the same charge limiting to iPhone as well.

brynet 3y ago
> This is interesting, am I correct in thinking this a feature implemented by Apple Yes, battery charge control is a hardware(/firmware) feature supported on other modern laptops as well, such as the Lenovo ThinkPads, but it's not a standard so it requires explicit driver and OS support. OpenBSD recently added support for this as well for both of these implementations (Apple silicon and ThinkPads). https://marc.info/?l=openbsd-cvs&m=168436150408382&w=2 https://marc.info/?l=openbsd-cvs&m=168436150408382&w=2 https://marc.info/?l=openbsd-cvs&m=168458409622780&w=2 https://marc.info/?l=openbsd-cvs&m=168458409622780&w=2 https://marc.info/?l=openbsd-cvs&m=168521616605492&w=2 https://marc.info/?l=openbsd-cvs&m=168521616605492&w=2 I know certain Android/Samsung phones support this as well, not sure about iOS/macOS.
- londons_explore 3y ago
  If your laptop firmware doesn't support it, here is one trick if you have a removable battery: Put a piece of paper over one of the batteries middle contacts. That will make the firmware think the battery is overheating. It will then refuse to charge, but will still happily discharge. You can do that to keep your battery at 80% while still on AC power. Handy if you operate from AC power 99% of the time, yet don't want your battery to die from being stored at 100% charge and hot for many years.
  - mschuster91 3y ago
    > Put a piece of paper over one of the batteries middle contacts. Bad, very bad idea if you don't know what you are doing - depending on where the "smarts" in the BMS are, you may damage your battery or make your BMS think the pack is broken or prevent your BMS from recognizing a charge state mismatch (and in the worst case, a cell going undervoltage or reverse polarity) as you have a good chance that you cut off one of the cell balancer contacts. This trick only works with removable phone batteries.
    - londons_explore 3y ago
      Would an engineer really make a consumer design where a sliding contact failing open led to a safety incident? Every laptop since the 90's has the balancing and protection circuitry inside the battery, not inside the laptop.
      - userbinator 3y ago
        Indeed, at worst you'll get a "no battery installed" and the laptop might not even try to discharge it. The comment you're replying to is just paranoic FUD. Which removable laptop battery has external balancing contacts!?!? They're all +/-/data.
        mschuster91 3y ago
        I'm a corporate firefighter assistant. If there's one thing people should not be messing around with, it's Li-Ion batteries. These things are dangerous enough even without people messing around with their control and management systems.
- Thews 3y ago
  I am on macos 13.3.1 and have noticed this feature for at least a couple of months, maybe longer. It says Charging On Hold (Rarely Used On Battery)
  - eisa01 3y ago
    I can never get that to activate, even though I use my MBP 14" 100% at home...
    - hedgehog 3y ago
      In my experience for it to take effect you need either a predictable window of plugged in time (it will delay charging until it needs to to hit 100% by when you normally unplug) or just to use your compute almost exclusively plugged in (at which point it will start letting the battery drift down to 80%). If you regularly unplug to work on the couch or whatever you may not ever see the effect directly unless you wake up an hour early to check the charge state of your laptop.
    - MobiusHorizons 3y ago
      It’s in settings under battery
  - windowsrookie 3y ago
    Optimized Battery charging has been available since Mac OS 11. Works on intel MacBooks too. https://www.macworld.com/article/235001/macos-big-surs-battery-optimization-you-cant-do-much-to-tweak-laptop-settings.html https://www.macworld.com/article/235001/macos-big-surs-batte...
- ficklepickle 3y ago
  I really want to try this out on my work ThinkPad since it stays plugged in effectively all the time. It requires a kernel module though, I'd need to get that approved first and I haven't got around to it. Naïve me doesn't understand why it can't be done from userspace, but I'm sure there is a good reason...
GeekyBear 3y ago
> I really hope Apple brings the same charge limiting to iPhone as well. This was added to iPhones in 2019. > If your iPhone stops charging at 80%, it's most likely due to a feature Apple introduced in iOS 13 called Optimized Battery Charging. It aims to prevent over-stressing the battery and hence extend the battery life of your iPhone by limiting the charge to 80%. Your iPhone learns your usage patterns and delays 100% charging until moments before you wake up in the morning. https://www.makeuseof.com/why-your-iphone-stops-charging-at-80-percent/ https://www.makeuseof.com/why-your-iphone-stops-charging-at-...
- vladvasiliu 3y ago
  It's a bit different, though. I don't often need my iphone to last multiple days on end. Yet, if I keep it plugged in as often as I'm sitting at a desk, it'll never go below 80%. If I get it below 80%, sooner or later, it will figure "i want to use it" and will charge it all the way to 100%. The lowest my battery ever got on this phone was 40 something when I was away for a weekend without a charger. It's very rare I use it a lot, so the "intelligence" clearly doesn't care how long the battery needs to last. The way it's implemented on my mom's android, it always shows 80 or 85% (can't recall which one it is), even if she leaves it plugged in for the whole weekend. On my HP laptop, if I activate the "battery saver mode" (as opposed to "AI"), it reports the maximum capacity as somewhere around 80% of the design capacity. I don't know whether Linux cooperates with this, but probably not. HP only talks about OS compatibility for the "AI" mode, which not only requires Windows but a specific HP app.
  - GeekyBear 3y ago
    > It's a bit different, though. Yes. It learns your normal waking time (if you have one) and gives you a full charge before you wake up. Which is what I want. A full charge for the working day, without needlessly shortening the batteries functional lifetime.
    - vladvasiliu 3y ago
      Sure, but if I know I won't drain my battery more than 10% that day, I can't tell it not to top it up more than 80%. That's the case for me 99.9% of days. This also seems to work only if you've drained the battery below 80%. If it says 90% and I plug it in? It'll charge it fully right away.
cyberax 3y ago
> This is interesting, am I correct in thinking this a feature implemented by Apple and now supported by the Asahi team? Does that mean that macOS supports this charge control feature? It does, but in a weird way. You can turn on "adaptive charging" and it will randomly decide to charge to 80%. If you want to properly control it, just install the wonderful AlDente utility ( https://apphousekitchen.com/ https://apphousekitchen.com/ ). Then you can manually control the max charge percentage. Mine is permanently set to 80% because I never really use even 40% of the battery on my M2-based laptop.

brynet 3y ago

> This is interesting, am I correct in thinking this a feature implemented by Apple Yes, battery charge control is a hardware(/firmware) feature supported on other modern laptops as well, such as the Lenovo ThinkPads, but it's not a standard so it requires explicit driver and OS support. OpenBSD recently added support for this as well for both of these implementations (Apple silicon and ThinkPads). https://marc.info/?l=openbsd-cvs&m=168436150408382&w=2 https://marc.info/?l=openbsd-cvs&m=168436150408382&w=2 https://marc.info/?l=openbsd-cvs&m=168458409622780&w=2 https://marc.info/?l=openbsd-cvs&m=168458409622780&w=2 https://marc.info/?l=openbsd-cvs&m=168521616605492&w=2 https://marc.info/?l=openbsd-cvs&m=168521616605492&w=2 I know certain Android/Samsung phones support this as well, not sure about iOS/macOS.

londons_explore 3y ago
If your laptop firmware doesn't support it, here is one trick if you have a removable battery: Put a piece of paper over one of the batteries middle contacts. That will make the firmware think the battery is overheating. It will then refuse to charge, but will still happily discharge. You can do that to keep your battery at 80% while still on AC power. Handy if you operate from AC power 99% of the time, yet don't want your battery to die from being stored at 100% charge and hot for many years.
- mschuster91 3y ago
  > Put a piece of paper over one of the batteries middle contacts. Bad, very bad idea if you don't know what you are doing - depending on where the "smarts" in the BMS are, you may damage your battery or make your BMS think the pack is broken or prevent your BMS from recognizing a charge state mismatch (and in the worst case, a cell going undervoltage or reverse polarity) as you have a good chance that you cut off one of the cell balancer contacts. This trick only works with removable phone batteries.
  - londons_explore 3y ago
    Would an engineer really make a consumer design where a sliding contact failing open led to a safety incident? Every laptop since the 90's has the balancing and protection circuitry inside the battery, not inside the laptop.
    - userbinator 3y ago
      Indeed, at worst you'll get a "no battery installed" and the laptop might not even try to discharge it. The comment you're replying to is just paranoic FUD. Which removable laptop battery has external balancing contacts!?!? They're all +/-/data.
      - mschuster91 3y ago
        I'm a corporate firefighter assistant. If there's one thing people should not be messing around with, it's Li-Ion batteries. These things are dangerous enough even without people messing around with their control and management systems.
Thews 3y ago
I am on macos 13.3.1 and have noticed this feature for at least a couple of months, maybe longer. It says Charging On Hold (Rarely Used On Battery)
- eisa01 3y ago
  I can never get that to activate, even though I use my MBP 14" 100% at home...
  - hedgehog 3y ago
    In my experience for it to take effect you need either a predictable window of plugged in time (it will delay charging until it needs to to hit 100% by when you normally unplug) or just to use your compute almost exclusively plugged in (at which point it will start letting the battery drift down to 80%). If you regularly unplug to work on the couch or whatever you may not ever see the effect directly unless you wake up an hour early to check the charge state of your laptop.
  - MobiusHorizons 3y ago
    It’s in settings under battery
- windowsrookie 3y ago
  Optimized Battery charging has been available since Mac OS 11. Works on intel MacBooks too. https://www.macworld.com/article/235001/macos-big-surs-battery-optimization-you-cant-do-much-to-tweak-laptop-settings.html https://www.macworld.com/article/235001/macos-big-surs-batte...
ficklepickle 3y ago
I really want to try this out on my work ThinkPad since it stays plugged in effectively all the time. It requires a kernel module though, I'd need to get that approved first and I haven't got around to it. Naïve me doesn't understand why it can't be done from userspace, but I'm sure there is a good reason...

GeekyBear 3y ago

> I really hope Apple brings the same charge limiting to iPhone as well. This was added to iPhones in 2019. > If your iPhone stops charging at 80%, it's most likely due to a feature Apple introduced in iOS 13 called Optimized Battery Charging. It aims to prevent over-stressing the battery and hence extend the battery life of your iPhone by limiting the charge to 80%. Your iPhone learns your usage patterns and delays 100% charging until moments before you wake up in the morning. https://www.makeuseof.com/why-your-iphone-stops-charging-at-80-percent/ https://www.makeuseof.com/why-your-iphone-stops-charging-at-...

vladvasiliu 3y ago
It's a bit different, though. I don't often need my iphone to last multiple days on end. Yet, if I keep it plugged in as often as I'm sitting at a desk, it'll never go below 80%. If I get it below 80%, sooner or later, it will figure "i want to use it" and will charge it all the way to 100%. The lowest my battery ever got on this phone was 40 something when I was away for a weekend without a charger. It's very rare I use it a lot, so the "intelligence" clearly doesn't care how long the battery needs to last. The way it's implemented on my mom's android, it always shows 80 or 85% (can't recall which one it is), even if she leaves it plugged in for the whole weekend. On my HP laptop, if I activate the "battery saver mode" (as opposed to "AI"), it reports the maximum capacity as somewhere around 80% of the design capacity. I don't know whether Linux cooperates with this, but probably not. HP only talks about OS compatibility for the "AI" mode, which not only requires Windows but a specific HP app.
- GeekyBear 3y ago
  > It's a bit different, though. Yes. It learns your normal waking time (if you have one) and gives you a full charge before you wake up. Which is what I want. A full charge for the working day, without needlessly shortening the batteries functional lifetime.
  - vladvasiliu 3y ago
    Sure, but if I know I won't drain my battery more than 10% that day, I can't tell it not to top it up more than 80%. That's the case for me 99.9% of days. This also seems to work only if you've drained the battery below 80%. If it says 90% and I plug it in? It'll charge it fully right away.

cyberax 3y ago

> This is interesting, am I correct in thinking this a feature implemented by Apple and now supported by the Asahi team? Does that mean that macOS supports this charge control feature? It does, but in a weird way. You can turn on "adaptive charging" and it will randomly decide to charge to 80%. If you want to properly control it, just install the wonderful AlDente utility ( https://apphousekitchen.com/ https://apphousekitchen.com/ ). Then you can manually control the max charge percentage. Mine is permanently set to 80% because I never really use even 40% of the battery on my M2-based laptop.