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by ianschmitz 722 days ago
I wish more devices offered a way to enable a “slow charge” mode.

When I’m plugging my laptop into my dock to work for the next 8 hours it doesn’t need fast charging.

When I’m plugging my phone in before bed to charge for the next 8 hours it doesn’t need fast charging.

5 comments

On my laptop I have a script to set

    /sys/class/power_supply/BAT0/charge_control_end_threshold
I could imagine automating this to set the threshold to the current battery level, and incrementing the threshold by 1% every N minutes to control charge speed.

Right now I try to keep it at 50% max charge like this while plugged in at home.

> When I’m plugging my phone in before bed to charge for the next 8 hours it doesn’t need fast charging.

iPhones do this with "Optimised Battery Charging" turned on (which I believe is the default setting) - "allow iPhone to wait to finish charging past 80% until the time you need to use it" (which it learns over time.)

Android has something similar. A notification pops up when I plug in at night, letting me know that it's charging slowly because I usually leave it plugged in overnight, and that I can disable it (once or permanently) to switch to fast charging.
As others have mentioned, many phones do this in software, but I find the easiest solution is simply to use a charger incapable of fast charging.
It's harder to do with a usb-c charger and laptop because the spec requires higher voltages are made available with higher wattages, and manufacturers only make products to hit sweet spots in the specs and market.

You might end up with a readily available 65W charger to get the necessary 20V, even if you don't want 3A.

https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Deliver...

i have 2 chargers near my bed, one has 3 amps, the other one has 1. i use one on another depending on how fast i need it charged. not the best solution, but it works.
I have a wireless charging cradle on my nightstand intentionally hooked to a slow charger. It works fine most of the time except on the rare occasion when the phone charge is low and I'm going somewhere in a couple of hours. It would be great if there was a charging cradle with a simple "fast/slow" charge switch.

Or even better, if phones had a built-in charge status UI that instead of just saying "NN% charged / TT minutes until full" had a slider controlling charge speed that showed a range of "time until full". That way users could intelligently choose the charge speed vs time based on context.

At least on Android it's possible to disable fast charging. It's in the battery settings on my phone.