Just turn off the main power line. Switch the power back in the morning. Safety first.
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Other Is it bad practice to leave your iPhone & Apple Watch on a wireless charger overnight?
- Thread starter The Cockney Rebel
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There is no data or proof for any of this, it may or may not. I look at this as more mental gymnastics than anything else. Too many variables. Anecdotally, the guy who baby sits battery has worse battery health than mine, which isn’t misused but charges overnight. My 13 PM after almost 3 years is still far from being replaced.
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Cost you pay for safety and battery health.
Apple Watch Series 3, using it for 2.121 days exactly.
Charging it on 5W Apple Charger overnight every night (6+ hrs).
Battery Health 100%.
Charging it on 5W Apple Charger overnight every night (6+ hrs).
Battery Health 100%.
Do you mean charge capacity or power capacity? Those are different, and each ages differently depending on usage pattern.
I have a Belkin 3-in-1 wireless chargher (this stand), I have turned on optimized battery charging and after 215 cycles I still have 100% battery capacity.
I have charged my Apple Watch Ultra and iPhone 14 Pro Max overnight (using the same charger) every night (optimized battery charging on). The Watch is now at 95% battery health (after 1.5 years) and the iPhone at 85% battery health.
I don't think the wireless charging heat is much of an issue, but I do think they would last longer if they stopped at 80%. I will cap new devices at 80%, and just bump it up to 100% as needed.
An enhancement Apple could make is to reduce charging speed if you charge overnight. Just bake it in to the optimized charging setting.
Thanks for the info.
My 14 Pro Max is at 94%, and my Apple Watch S8 is at 99%.
I’ve never left them on charge overnight.
I actually have an Automation that tells me when my iPhone (and iPad) are fully charged. I also get a silent notification on my watch, when my iPhone is fully charged.
I am using the charging pad. Been using it since I bought my 15 PM with no issues 👍
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It’s also a topic that’s very prone to the placebo effect.
In “serious” automotive circles, there’s a tendency to prefer manual transmissions over automatic because “I can maximize fuel economy/preserve my motor’s health thanks to my skill at driving a manual” (oversimplification, but, oh well), and there’s been some handwringing over computerized automatic transmissions. Battery charging seems a lot like that. Just learn to love the [battery charging circuitry].
I don't have the cycle count in front of me, but I imagine the differences in health could be due to usage (rather than how they are charged). I have used my phone for app development.
What are you even talking about here? Making **** up and calling it science doesn’t make it science.
If you use a 5v 2.1a charger it will be easier on batteries than say 9v 3a (going from memory but I think that’s the charging profile Apple uses for usb c fast charging 14 down). But claiming that voltage gets higher because you charge overnight is false. Voltage stays consistent during your charging cycle and amperage drops as the batteries charge level gets higher. Want proof? Buy a volt meter and check it yourself. The reason your battery degrades from charging is because the heat caused by higher amperage chargers degrades the chemistry.
Think of power as this (mind you not a perfect analogy):
Voltage is the number of lanes on a highway
Resistance is the roads condition (pot holes and other factors that prevent you from going faster. You can’t go 90 on a bumpy dirt road)
Amperage is the speed limit
The faster you go the more heat and wear you cause. A higher voltage is preferable to a higher amperage but both play a factor. The best you can do is use a 5v charger overnight and realistically any 5v any amp charger will be fine. Charging in the 5v usb spec doesn’t generate as much heat as it used to.
Personally I charge my iPhone with whatever charger is available. I’ve got usbc and standard 5v usb chargers at my bedside and in 3 years my iPhone 13 is at 97%. In 6 years my XS max is at 87%. In 7 years my 2017 10.5 iPad Pro is at 84%. The charging logic Apple uses is very good and does all the work. Trust your device, use it like you want, and like others said if you’re really dedicated to it keep your charge level between 20% and 80% but with all that effort your just wasting your time you could spend on something more fulfilling. That’s why we have charging and power management circuits, they work.
As for the fire risk argument. Someone said the main breaker is enough but what if the breaker catches fire? Or the connection to the house does? What if the next city block catches fire because they forgot to turn their block off like someone suggested? Best to just shut down the local substation and save your city from becoming the next California wildfire.
Edit: I make usb battery packs on my time off and have thoroughly researched this topic as well as taken classes in it so while your base logic is right, the application of it is not.
I noticed something with my iPhone 14 Pro. I overnight wireless charged it on the Apple MagSafe charger for the first 9 months I had it. I was down to 90% battery health in only 9 months. I had to get an AppleCare replacement for it and on that phone I did NOT overnight charge it and switched to plug in charging 90% of the time. I had an unfortunate accident and it was collateral damage in my fall but in the year I had it the battery health was at 96%. My hubby also has my old iPhone 13 Pro and he doesn’t wireless charge it and it’s still at 93% battery health.
I’ve never had a phone drop battery health like that first 14 Pro that I only wireless charged and charged overnight every night. Never. So I’ve stopped overnight wireless charging.
Take from that what you will.
I’ve never had a phone drop battery health like that first 14 Pro that I only wireless charged and charged overnight every night. Never. So I’ve stopped overnight wireless charging.
Take from that what you will.
Wireless charging creates a lot of heat. A basic QI charger is particularly bad. MagSafe (or QI2) generates less heat but still more than wired and with the increase in MagSafe charging speeds I suspect we’ll see similar heat generation as the original QI chargers. With the newer charging speed for MagSafe we’ll need more time to see what effect it has in the real world.
Of course defects and different manufacturers can cause differences between devices too so it’s a bit of a toss up.
I have owned several Apple Watches over the year, and they have all been charged in similar ways. Yet their batteries have degraded with different patterns.
As an example, my Apple Watch Ultra stayed at 100% for the entire first year. This does not mean that its health did not degrade, and it does not mean that means my charging habits were superior (whatever that means).
Good battery habits are not that hard:
- Keep them between 20-80% (or possibly even 30-70%)
- Avoid extreme temperatures
Both of these are things Apple could manage with software, if they wanted to.
I use 80% limit on my 15PM and I do my best to do that manually for watch. I do not overnight charge and only charge during the day, and take off the charger as soon as it's there. Have been doing for years and seems to have a positive effect on longevity. I usually upgrade iPhone annually, and am always at 100% battery health, but my watch Series 5 is doing well on battery too, and I've had it long enough to have more results. No battery life issues.
Bad practice? Depends on your goal. Wireless charging will degrade your battery more, leaving it on a charger even more so. Otoh, there‘s no other way to charge a watch than wireless. Apple‘s intelligent charging will mitigate the effect of leaving your devices on a charger, but it won’t mitigate it fully. In my case, my life is to irregular for this feature to work. (e.g. I usually get up everyday between 6am and 11am - with exceptions - depending on my work that day). Also, it depends on how long you‘re planning to keep your device. It won‘t make much of a difference if you want to buy a new one over the next 2-3 years anyway. In my experience it‘s not worth the hassle to think much about this, app usage and luck/bad luck with the battery will have a greater impact. If you want to maximise your battery life, don‘t use a wireless charger, charge slowly and keep the charging state between 20-80%, if possible.
Oh I know, it’s anecdotal definitely, but I was way heavier with wireless charging with that first 14 Pro and the second was back to my usual battery degradation from previous devices. Thought it was awfully coincidental.
While it's true that heat is a primary factor in battery degradation, it's not wireless charging itself that's inherently harmful. The culprit is often poorly designed or incompatible wireless chargers that generate excessive heat.
Apple's MagSafe technology, for example, is designed to optimize charging efficiency and minimize heat generation. When used with certified MagSafe chargers, it's a safe and convenient way to charge your devices.
The key is to choose high-quality wireless chargers that prioritize heat management. Look for chargers that are Qi-certified and have built-in thermal protection features. Additionally, avoid using your phone while it's wirelessly charging, as this can contribute to heat buildup.
As for leaving your phone on the charger overnight, Apple's Optimized Battery Charging feature is designed to mitigate the negative effects by learning your charging habits and delaying charging past 80% until you're likely to need it. However, if your schedule is highly irregular, it might not be as effective for you.
The best approach is to be mindful of your charging habits and use reputable chargers. Whether you choose wired or wireless charging, prioritizing heat management will go a long way in preserving your battery health.
You are thinking about voltage and current at the wall charger versus at the cells. Well, it's constant at the wall charger for most charge standards but the more modern ones are changing that too. I really hope your homemade battery packs do not put constant voltage across those cells!
Voltage at the cell does not match the voltages you indicate. Want proof? If you connected a constant 9V, 3A source to a nominally 3.81V iPhone battery you'd be wasting 9*3 - 3.81*3 = 15.57W in whatever internal resistor was providing that voltage difference.
You also can't have constant voltage at the cell. Proof: Your 9V, 3A charger provides about 27W maximum. At a 3.81V nominal cell voltage that means your cell is capable of drawing about 7A of charge current. Your 5V, 2A charger only provides about 10W maximum power. At a 3.81V nominal voltage, that is only 2.6A available. What happens when you try to draw 7A from a 2.6A source? The voltage would drop.
What really happens is that the battery goes through a few phases: First a low current charge phase to ensure the cell is ok to accept higher current. Then a constant current phase where the voltage applied is slowly raised as the cell voltage rises in order to keep constant current and thus maximum power into the cell. As the cell gets closer to capacity, the applied voltage is capped and a constant voltage is applied as the charge current diminishes until capacity is reached.
(That curve will be different for different devices, but it illustrates my point)
How is the voltage at the cell changed? Traditionally, it's managed by the internal charge circuit of the device. A USB voltage is negotiated, and then internal charge circuit converts that to the voltage it needs to apply to the cells. More modern chargers have modes such as PPS which also allow the wall adapter to provide continuously varying voltages into the device to make the internal charger as efficient as possible.
Batteries don't only degrade from heat, in fact it's arguably worse to charge batteries too cold (but the internal heating makes that harder to do unless the ambient temperature is quite low). There are a number of mechanisms that degrade batteries-- average cell voltage, peak cell voltage, depth of discharge, total current passed, temperature, time, chemistry, physical construction-- and they all interact and affect the ability of the cell to store charge and the internal resistance (ability to deliver power) differently.
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