Probably wearing your batteries out more. Bunch of studies done have found fast charging causes no additional degradation. Unless you hold the charge below 90% or something letting them dwell at 100% for hours is worse.

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appreciatorBus 2 days ago | parent | next [-]

Yes I’m aware of the studies re: fast charging , and the importance of avoiding dwelling at high charge levels :)

If a device charged overnight does not support limiting charging to 80%, a 5W charger means the device spends less time between 80% and 100% versus a higher wattage charger.

For a newer device that does support limited charging to 80%, I agree that there’s probably a little difference in battery aging between different speed chargers, however for overnight charging, where I really don’t care how long it takes to charge, I would still go with the lower power.

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Barbing 3 days ago | parent | prev [-]

Why wearing out more? I’d been planning on pulling out an old charger to slow charge overnight.

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red369 3 days ago | parent [-]

I suppose the previous comment was likely saying more compared to not charging overnight, and fast charging in the morning.

I would also have guessed the slow charging was better, but that is an uninformed opinion. I'd be quite interested in what people think.

An extra dilemma - often if I'm around the house or the office all day, I'll just plug in my phone every time I see it reach about 70%, and unplug when it reaches 80% (this is easier to spot if you have low-power mode on for an iPhone because the screen lights up at 80% when low-power mode is turned off). Is it worse to do that 2 or 3 times, compared to just charging to 100% and leaving it on the charger all day. Is being at 100% all day, but not using any (fractions of) charge cycles, worse than doing a few shallow discharges?

Of course, I don't think it really matters, but it's the kind of thing that I wonder and then do when I remember.

	▲	appreciatorBus 2 days ago \| parent [-]
		To be clear, I also don’t think it really matters. :) That said, my assumption is that most people want to charge overnight precisely because they do not want to have to remember to do a fast charge in the morning. Maybe that’s just me tho. Assuming you want to charge overnight, I totally agree that spending less time between 80% and 100% is good, and software that either prevents this or limits it is good. But whether you have such a device or not, for overnight charging a lower power charger seems prudent.