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Comment by rootusrootus | Hacker News Reader

I wish they'd give us the option (on the iPhone and iPad as well) to arbitrarily set the maximum charge level. Just like on my Tesla, I'd like to be able to tell my phone not to charge above 80%.

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Then 500M people complaining on Reddit that their phones only charge to 80% for some reason.

And then they’ll do the same thing they did to the antenna signal strength bars and fake it to make people happy...

you can mostly fix this issue by hiding the option in "developer settings". on android, there's a lot of weird stuff buried in here but you never hear people complaining about it.

Easy: make the charge percentage display relative to the maximum configured charge. Just like it already is with battery deterioration over time: if my battery only holds 80% of its design capacity, the phone will still tell me to be 100% charged as soon as the battery hits that 80%-of-design-capacity-brick-wall.

I just want the option to manually move that brick wall down a bit (they're already telling me exactly where it is right now, on iPhones at least, on the MacBook I ask coconutBattery).

Then they'll be complaining their phone only lasts 8 hours before a charge instead of 10.

If they do that after deliberately reducing their maximum charge (a setting which would probably come with a warning that reduced runtime of the phone is the result of doing it), they'll probably also complain that their internet speed has gone down after disabling the LTE/4G option (actually that does seem to be even less transparent, because not everyone knows that LTE is faster than 3G). Didn't stop Apple from offering a switch to disable LTE/4G.

They could probably get away with changing what is technically 95% to read as '100'

I realised the other day that Macs don't give 'battery time remaining' anymore, although I'm not sure when that was removed

Edit: apparently you can still see time remaining in Activity Monitor

Note that essentially all modern battery systems essentially do this under the hood. The "100%" shown to the user isn't the most you could charge the cells, just as high as you want to charge it to meet lifetime degradation targets. Tesla just goes a bit crazier here and exposes more headroom because they can rely on drivers being more involved in charging strategies.

What separates drivers from phone/laptop users? Certainly not techies vs normals. It would seem to me that both cohorts are capable of, and potentially interested in, deciding between "shorter days but more years" and "longer days but fewer years."

I think the real difference is that car manufacturers' business health depends on less maintenance over many years, and phone manufacturers' business health depends on planned obsolescence.

Cars have way more capacity than they typically need, and very predictable usage patterns. If your car has 400 km of range and your daily commute is 80 km total, you can pretty safely charge to only 200 km and not get range anxiety. In the rare cases where you need as much capacity as possible (road trips), you know your approximate departure time, so the battery only needs to be at maximal charge for a short time.

Laptops don't get used like that. People plug them in, then unplug and walk around with them until they either they run out of power or their meetings are over. It's really asking too much to have people plan their usage out. Plus the draw rates aren't predictable. If I can get away with just checking email, my laptop lasts all day. If I have to do a big C++ compile that's 30 watt-hours right there.

I might also add that really only Tesla is doing the charging guidance UI. Other car manufacturers spend a lot of resources to perpetuate the illusion of a battery working like a fuel tank.

Some laptops support this too (eg business Thinkpads). Apple is a luxury brand and batteries are cheap to replace so it doesn't want to burden users to spend their precious cognitive capacity on battery management.

Long time ago Ezekeel, a xda-developers user, published a kernel mod for the Nexus S that let you choose the max percentage that the battery could reach while charging. It was called BLX aka Battery Life eXtender. I always set it to 80%. I've always been intrigued by extending the life of li-ion cells and that's the only work that goes into that direction AFAIK. I believe it was 2011. There hasn't been anything like that ever since.

There's AccA (and the command-line ACC) which allow fairly sophisticated control over max voltage and charging rates, with easy profile switching (features depend on kernel/hardware, but works with a lot of stock ROMs). Root is required, unsurprisingly.

https://github.com/MatteCarra/AccA/releases/

>There hasn't been anything like that ever since.

https://github.com/sriharshaarangi/BatteryChargeLimit/

root required, obviously.

This is exactly what I was thinking. The article doesn't mention if there is a setting to temporarily allow the battery to charge to a higher percentage.

I assume checking the box to not use this setting will work the same way but I want to make sure I switch it back. Just like how Tesla prompts you intermittently.

The only thing wrong with my Note 8 at this point is battery life. I'd gladly have dealt with 80% charge over its entire life in order to still have a good battery life now.

iOS has made steps towards this by learning your charging habits (e.g at night), going to 80%, and wait to the last minute before topping up.

My Asus Zenfone 6 does this. It also seems to modulate the charge current to a low level if charging overnight. A tap on the notification engages full charge power.

This is something I have heard about but have yet to experience. Maybe my charging habits are too irregular.

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