5 ms·

Why doesn't the UI report 80% as 100%? It seems like exposing this to the user is more confusing than anything, when the cells could be over provisioned and tre

• Lammy 7y ago
  Reminds me of how they changed Finder in Mac OS X Snow Leopard (10.6) to report disk capacity in base-10 bytes instead of base-2 bytes.
  • duskwuff 7y ago
    Eh. That was more for consistency with how storage devices are sold -- if a 10^30 byte hard disk is described by storage vendors as "1 TB", it's incredibly confusing to users to have it show up as "931 GB".
    • noisem4ker 7y ago
      There's nothing wrong with letting users learn how hard disk marketers are ripping them off, instead of playing their game. But, as usual, Apple prefers to choose blissful ignorance for their sheep customers. Besides that, we have proper units for binary multiples: KiB, MiB, and so on. I've only seen KDE use them properly so far, and it's a shame.
      • userbinator 7y ago
        Besides that, we have proper units for binary multiples Approximately 0 average users know about them, and of the technical users, only the truly irritatingly pedantic are going to use them (which may be why they've shown up in Linux).
        • noisem4ker 7y ago
          That added "i" inbetween can go unnoticed for those not caring, it can be an invitation to learn for the curious, and most importantly it is an important disambiguation for those who know. The trade-off is absolutely positive to me.
      • hunter2_ 7y ago
        Is it really "ripping them off" to use SI prefixes for base 10 just because (a huge number of) other people are accidentally using SI prefixes (base 10) when they really ought to be using IEC prefixes (base 2)? Calling it a a "2 TiB disk" when it's actually a 2,000,000,000,000 B disk would be a blatant ripoff.
• kevingadd 7y ago
  Some samsung tablets (and phones, I think?) have an option that does this - it remaps 80% so it appears as 100% and won't charge past it. Nice way to improve battery health for a device that spends a good chunk of every day plugged in. A fun side effect of this is that the tablet can boot while at '0%' battery, and then it will automatically shut off a little bit later to avoid dipping below the safe range - presumably '0%' is actually like 10% or so.
• atombender 7y ago
  It's my understanding that modern EVs like the Kia Niro EV or the Chevy Bolt work this way. When nominally charged to 100%, the actual charge is closer to 80%. A 75 kW battery will typically only go to 64 kW.
  • floatrock 7y ago
    During one of the last few hurricanes, Tesla did an OTA update that unlocked extra range for people trying to leave. I seem to remember it being something like the hardware capacity is one number but there's a software upsell that you normally need to pay to unlock full capacity. But it may have also been a "we'll push the normal operating parameters to give you this extra boost", don't quite remember.
    • szhu 7y ago
      Tesla sells two versions of that car, one with longer range, even though they have identical hardware. During the hurricane, they lifted the software cap on the shorter-range version.
    • battery_cowboy 7y ago
      With their Powerpack products, Tesla oversizes the inverters and capacity a bit to deal with reduced capacity over time, so if you have a 1 MWh battery, they might install 1.15 MWh and limit to 1 MWh so that in 20 years it still has a 1 MWh capability.
    • aeyes 7y ago
      Tesla has a very minimal top buffer though, it is only used to offset the known degradation of the new battery. After 6-9 months you'll have no top buffer left. You can tell because charging from 99 to 100% is at extremely low amps and takes forever.
  • fulafel 7y ago
    All li ion batteries work this way. If the battery mapped 100% to the chemical max capacity, your batteries would degrade very fast and die very young. This whole discussion is colored by confusiin between the heavily simplified model presented by the charge indicator with the raw battery properties. Fun fact: there is no "80%" level either as seen from the battery controller POV, that's just a forecast about how much energy the battery might be able produce if run until the cut-off level (and the 0% level here is also a fair bit above the chemical empty state), and the battery controller is constantly updating its model about how the battery behaves when discharging to keep the forecast accuracy reasonable when the battery ages. When the batteries come from the factory, the calibrations for 0%, 80%, 100% are at certain voltages, and they constantly move throughout the life of the battery. (Maybe not the 0% voltage)
• Marsymars 7y ago
  > Why doesn't the UI report 80% as 100%? The Verge piece on this says that this is what will happen. https://www.theverge.com/2020/4/16/21223607/macbook-battery-health-management-charge-percentage https://www.theverge.com/2020/4/16/21223607/macbook-battery-...
• chipotle_coyote 7y ago
  > Why doesn't the UI report 80% as 100%? Because the last time they tried "silently manage the battery without the user being part of the decision" it didn't go over real well?
  • outworlder 7y ago
    That wasn't even managing the battery, per-se(although it is power management, it wasn't strictly about health). It was reducing clock speeds to extend the amount of time the device would be on. They still do it even if the device has a healthy battery: drain the phone to 1% and you will see. Rather than running at full blast and shutting down, you can extract more runtime. Some EVs do something similar: the Nissan Leaf, when the battery gets really low(and I mean it, far past the point where you lost all percentage and mileage indicators), will enter a reduced power mode (or popularly called "turtle mode"). This allows it to eke out a few more miles out of an otherwise mostly dead battery. There is a "turtle" that lights up on the screen, maybe Apple could just do that. Turns out batteries hate when they are almost empty and you are trying to extract full power from them, voltage drops even more. So there are some compromises that have to be made.
    • NickNameNick 7y ago
      The problem was the phones battery couldn't deliver enough current to run the cpu at full power, even though it had charge remaining to run the phone for some period of time in a lower power mode. Without power management, when a high demand task came alone and the CPU tried to draw more power, the phone would crash or shut-down. The firmware update capped performance not to extend the run-time when the batteries were low, but to allow the phone to run reliably when the batteries were worn.
    • saagarjha 7y ago
      > the Nissan Leaf, when the battery gets really low(and I mean it, far past the point where you lost all percentage and mileage indicators), will enter a reduced power mode (or popularly called "turtle mode") TIL. I thought I was pushing it coming home with 2 miles left…
  • 7y ago
• symmitchry 7y ago
  Well, as a user, wouldn't it be nice if I could access 100 % of my battery for situations where I need as much life as possible? 20 % is fairly significant. It also cuts down on battery longevity, but plenty of people might not care at all.
  • Polylactic_acid 7y ago
    Would be a fine feature if it was exposed in a setting for the user to pick.
  • cmckn 7y ago
    For sure, a "extra battery" mode could make sense as the opposite of "low power" mode. Still, that smells like the sort of feature the average user would be superstitious of, like the obsessive app force-quitting I see folks do on the bus all the time.
• unbendable 7y ago
  I just switched from Linux to Mac for my company notebook. No offense, but for me it is like the Mac is taking my hand and guiding me threw a mess. However sometimes I know the way better than the Mac but it is not letting me. It actually makes it really hard to „go my way“. For example the “only trusted developer program“ can be run . I understand why it makes sense for most people but I want an option to decide it mysel who is to be trusted. To be fair I had to google a bit for a terminal command to fix this but either way it leaves a bitter taste. I fear that I may lose this “fix“ Now back to the battery health. Why not allow being transparent? If most of users want the 100% showing then make it default. I think that’s what boils it down for me. Having no choice with OS X. Now I know some will say that’s how it is for Mac but do you think it is too much to ask for this (really stable) system to support choices?
  • madeofpalk 7y ago
    I can not align with this. "Gatekeeper", the ‘only trusted developers’ setting is a setting in System Preferences. Windows also ships with an equivalent setting in the default.
• bonestamp2 7y ago
  I believe macOS already does this. Not down to 80%, but sometimes when it shows 100% and you check the battery info, it shows that it is actually still charging.
• imtringued 7y ago
  That SSD analogy is wrong. Doubling the capacity doubles the lifespan of the device. The reason why there is extra space is because performance of a full SSD can degrade to unacceptable levels. Basically you can write and erase but you can't overwrite flash. If the drive is full the writes are queued in the over provisioned part of the SSD and once the garbage collector has run and freed up space the pending writes are transferred back onto the regular storage.