Proper phone charging

billt460 said:
Motorola Moto E phone with this charger. I usually charge both the phone, and my JBL TV headphones with it at the same time. Both take about the same time to charge.

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There are many "E" phones. Is it this one?
www.phonearena.com

Motorola Moto E (2020) specs

Motorola Moto E (2020) specifications - Display: 6.2 inches IPS LCD; Camera: 13 MP (PDAF); Processor: Qualcomm Snapdragon 632 SDM632 (14 nm); RAM: 2GB LPDDR3; Battery: 3550 mAh
www.phonearena.com www.phonearena.com

According to specs, it can only charge at 5W, so that isn't fast charging, which is why your phone is not getting warm, but I'm surprised that you can charge it from 20% to 100% in 1 hour.

Even if the phone is capable of charing with higher power, that charger can only deliver 12W across both ports combined, so if you have something else charging at the same time, your phone is receiving whatever is leftover, maybe half of that.
 
JHZR2 said:
Ohms law. Are you denying it?

Maybe your nerves are numb. Maybe the phone is on a big, cool mass. I don’t know the situation.

If the resistance of the battery is lower, the heat generated is lower.
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The heat generated while charging a phone is not primarily from the battery unless you've got a phone with 97%+ efficient converters and charging at a big C multiple. LiPo packs have extremely low internal resistance. Most of the losses occur in the DC-DC converters of the charging circuitry or with Qi, the poor magnetic coupling. There can be big differences in phones depending on PCB layout, efficiency of the buck converters, etc.
 
KrisZ said:
Yup, more money for Apple, because the cable they ship with iPhones is usb-c instead of usb-a so it doesn't work with the 5w cube.
The iPhone box is also smaller so they can ship more of them with the same size container.
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That's true, but the EU and environmental groups have also been pressuring manufacturers to not bundle to cut down on waste.
 
Hermann said:
To prolong battery life only charge to 80-85%, many Samsung phones have that feature, which shuts off charging at 85%. Don't know about other phones.
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My Android Motorola "G Pure" doesn't have that feature. I wish it did. However, I obtain about the same effect by charging through a timer, knowing that it charges about 0.6% per minute from the standard 10-watt (nominal) charger. Before I got the timer, I accidently let it charge to or near 100% a few times.
 
chris719 said:
The heat generated while charging a phone is not primarily from the battery unless you've got a phone with 97%+ efficient converters and charging at a big C multiple. LiPo packs have extremely low internal resistance. Most of the losses occur in the DC-DC converters of the charging circuitry or with Qi, the poor magnetic coupling. There can be big differences in phones depending on PCB layout, efficiency of the buck converters, etc.
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Anything and everything is impacted by I^2R

I don’t fundamentally disagree with your comment though. Lots of other stuff that has little inefficiencies that add more heat inside a tight packed phone…
 
JHZR2 said:
Anything and everything is impacted by I^2R

I don’t fundamentally disagree with your comment though. Lots of other stuff that has little inefficiencies that add more heat inside a tight packed phone…
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Yep, and the R in a phone battery is very small. I have a 1800 mAh cell on my desk that measures at around 7 mOhm. If you short the terminals without a protection circuit in place the clip leads will start glowing within half a second. If I charged this battery at 5 A (2x higher than it's rated for), it would dissipate 0.175 W.
 
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chris719 said:
Yep, and the R in a phone battery is very small. I have a 1800 mAh cell on my desk that measures at around 7 mOhm. If you short the terminals without a protection circuit in place the clip leads will start glowing within half a second. If I charged this battery at 5 A (2x higher than it's rated for), it would dissipate 0.175 W.
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Don’t disagree. But it does create localized heating, and impedance rises with age and exposure to the rest of the phone getting hot. Plus the stress and strain of charging full.
 
How about this... Charge to 80% or so, then shut down for say an hour, and allow everything to, "cool down". Then charge the remaining 20% until full. Will that help anything?

Elon Musk said on Joe Rogan's podcast, that charging Lithium Ion batteries is like letting people into a room full of chairs. The first bunch in can easily find chairs to sit in. (Charging a low battery).

But as more and more people pile into the room, (battery becomes more fully charged), they keep bumping into each other trying to find the last few chairs that are left. And all of this "bumping" is where the heat comes from.
 
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billt460 said:
How about this... Charge to 80% or so, then shut down for say an hour, and allow everything to, "cool down". Then charge the remaining 20% until full. Will that help anything?

Elon Musk said on Joe Rogan's podcast, that charging Lithium Ion batteries is like letting people into a room full of chairs. The first bunch in can easily find chairs to sit in. (Charging a low battery).

But as more and more people pile into the room, (battery becomes more fully charged), they keep bumping into each other trying to find the last few chairs that are left. And all of this "bumping" is where the heat comes from.
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Why overthink it? I seriously doubt charging more often (as in more complete cycles) while limiting the charge to 85% is any better long term than charging to 100% for that extra bit of capacity. I take care of my devices for maximum longevity, but at the end of the day don't wanna have to babysit something to possibly get 1% longer useful life out of it in a 3-4 yr time span.
 
billt460 said:
How about this... Charge to 80% or so, then shut down for say an hour, and allow everything to, "cool down". Then charge the remaining 20% until full. Will that help anything?

Elon Musk said on Joe Rogan's podcast, that charging Lithium Ion batteries is like letting people into a room full of chairs. The first bunch in can easily find chairs to sit in. (Charging a low battery).

But as more and more people pile into the room, (battery becomes more fully charged), they keep bumping into each other trying to find the last few chairs that are left. And all of this "bumping" is where the heat comes from.
Click to expand...

Yeah but Tesla superchargers are not comparable to 25W phone chargers.
SuperVOOC 65-160W automatically slows down at 80% and when temperature are too high or low.
 
JonnyRingvald said:
Why overthink it? I seriously doubt charging more often (as in more complete cycles) while limiting the charge to 85% is any better long term than charging to 100% for that extra bit of capacity. I take care of my devices for maximum longevity, but at the end of the day don't wanna have to babysit something to possibly get 1% longer useful life out of it in a 3-4 yr time span.
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I agree. But if this heating is so bad, why not try to avoid it if you can? My last Motorola phone was almost constantly left plugged in, on charge. I only took it off when we went somewhere. It lasted several years.

The only thing I noticed is that the battery swelled a bit. But it still functioned perfectly. I have heard people say this has happened to them with normal charging and discharging cycles.

And there always are stories about Lithium battery fires happening. From phones, to electric scooters, to laptops. Boeing even had a problem with Lithium batteries on it's 787 when in development. So the overheating of these things appears to be a legitimate issue, that is best to avoid if at all possible.
 

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billt460 said:
I agree. But if this heating is so bad, why not try to avoid it if you can? My last Motorola phone was almost constantly left plugged in, on charge. I only took it off when we went somewhere. It lasted several years.

The only thing I noticed is that the battery swelled a bit. But it still functioned perfectly. I have heard people say this has happened to them with normal charging and discharging cycles.

And there always are stories about Lithium battery fires happening. From phones, to electric scooters, to laptops. Boeing even had a problem with Lithium batteries on it's 787 when in development. So the overheating of these things appears to be a legitimate issue, that is best to avoid if at all possible.
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I never leave a device plugged in after it hits 100% and always charge them in front of a desktop fan. If I need to charge in transit my phone is positioned in front of a vent with air on.
 
JonnyRingvald said:
I never leave a device plugged in after it hits 100% and always charge them in front of a desktop fan. If I need to charge in transit my phone is positioned in front of a vent with air on.
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I have several of those refreezable gel ice packs you put on sore knees, sprains and the like. What about sitting it on one of those?
 
billt460 said:
How about this... Charge to 80% or so, then shut down for say an hour, and allow everything to, "cool down". Then charge the remaining 20% until full. Will that help anything?

Elon Musk said on Joe Rogan's podcast, that charging Lithium Ion batteries is like letting people into a room full of chairs. The first bunch in can easily find chairs to sit in. (Charging a low battery).

But as more and more people pile into the room, (battery becomes more fully charged), they keep bumping into each other trying to find the last few chairs that are left. And all of this "bumping" is where the heat comes from.
Click to expand...

There’s a few phenomena here.

Li-ion is an intercalating battery. The li goes between planes of graphite in the anode. The easiest spots to slide in go first. Elon’s not wrong…

On top of that. The graphite swells. It’s a planar structure. Imagine shoveling bbs between sheets of paper… and the electrodes swell and crack with charging too high and often.

Do it too fast and you can plate lithium too.

The best bet is to avoid going over 80% if you can.

The latest iPhone sw has this option. I’d assume your phone has something like it too.
 
JHZR2 said:
There’s a few phenomena here.

Li-ion is an intercalating battery. The li goes between planes of graphite in the anode. The easiest spots to slide in go first. Elon’s not wrong…

On top of that. The graphite swells. It’s a planar structure. Imagine shoveling bbs between sheets of paper… and the electrodes swell and crack with charging too high and often.

Do it too fast and you can plate lithium too.

The best bet is to avoid going over 80% if you can.

The latest iPhone sw has this option. I’d assume your phone has something like it too.
Click to expand...
The last few phones I've had will 'supercharge' until it hits in the 80s%, then is designed to slow down to the finish. Higher end phones no doubt have safety measures built in to minimize long term fast charging damage. Been charging every phone I've had to 100% for many years and have yet to have any sort of battery issue and most phones I have had for 3-4 yrs with moderate daily use. Have only upgraded over time for up-to-date software applications, that sort of thing. This subject reminds me of some buying a vehicle then afraid to drive it in less than perfect conditions. It's made to be driven!
 
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