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snerkler

macrumors 65816
Original poster
Feb 14, 2012
1,170
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I've just bought the iPad Pro 11" and looked on google and have seen that I can charge it with my MBP's 87W USB-C adapter too which is great if I ever forget to take my iPad charger somewhere and have my MBP one. However, I can't find any info as to which would charge the iPad quicker and which one (in theory) should give it a longer lasting battery (if any).

So, which will charge the battery fastest, the bundled 18W or my MBP 87W adapter, and which (if any) will give it a longer battery life between charges?
 

haruhiko

macrumors 604
Sep 29, 2009
6,691
6,245
I've just bought the iPad Pro 11" and looked on google and have seen that I can charge it with my MBP's 87W USB-C adapter too which is great if I ever forget to take my iPad charger somewhere and have my MBP one. However, I can't find any info as to which would charge the iPad quicker and which one (in theory) should give it a longer lasting battery (if any).

So, which will charge the battery fastest, the bundled 18W or my MBP 87W adapter, and which (if any) will give it a longer battery life between charges?
As I remember the iPad takes more than 18W of power in charging so your 87W may be faster.
 
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zhenya

macrumors 604
Jan 6, 2005
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The 87W charger will charge the iPad Pro at 9V/3a or 27W - so considerably faster than the included charger. There are chargers available that support 15V/2a or 15V/3a that will charge at 30/36W respectively.
 

zhenya

macrumors 604
Jan 6, 2005
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The kind of 'fast' charging that we are getting to now is only relative - the prior iPad chargers were simply ridiculously slow. We are nowhere near the point of doing damage to ones battery, and the charge automatically tapers as the battery fills, mitigating the possibility of any damage. The thing I like about fast charging is that you can so quickly inject a bunch of power into the device. This allows you to have a usage routine that should be far better for the battery - rather than leave it on a charger until it is 100% full (the worst state for a battery to be kept in other than 0%), I simply pop it on the charger for 30-40 minutes in-between use. I rarely charge it to 100%, and rarely let it drop below 20%. This is the sweet spot for battery longevity, and it's much more practical to keep the battery in this zone with fast charging.

FWIW I charged my 2015 Macbook almost exclusively on a low-power (12w) usb-c charger. That battery is at 68% capacity after 3 years and less than 450 cycles.
 

Newtons Apple

Suspended
Mar 12, 2014
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The kind of 'fast' charging that we are getting to now is only relative - the prior iPad chargers were simply ridiculously slow. We are nowhere near the point of doing damage to ones battery, and the charge automatically tapers as the battery fills, mitigating the possibility of any damage. The thing I like about fast charging is that you can so quickly inject a bunch of power into the device. This allows you to have a usage routine that should be far better for the battery - rather than leave it on a charger until it is 100% full (the worst state for a battery to be kept in other than 0%), I simply pop it on the charger for 30-40 minutes in-between use. I rarely charge it to 100%, and rarely let it drop below 20%. This is the sweet spot for battery longevity, and it's much more practical to keep the battery in this zone with fast charging.

FWIW I charged my 2015 Macbook almost exclusively on a low-power (12w) usb-c charger. That battery is at 68% capacity after 3 years and less than 450 cycles.

None of the above saves on cycles and I am not going to baby sit my iPad while it charges overnight. Never had any battery problems with any of my iPhone or iPads and I have owned all of them.

Enjoy!
 

zhenya

macrumors 604
Jan 6, 2005
6,931
3,681
None of the above saves on cycles and I am not going to baby sit my iPad while it charges overnight. Never had any battery problems with any of my iPhone or iPads and I have owned all of them.

Enjoy!

Cycles are not what causes a battery to fail. Running it to its extremes is. This is why hybrid vehicles like the Prius or the Volt only use the portion of the total battery capacity from ~40-80%. And it's why even Tesla only charges to 90% unless the user over-rides that selection manually. These batteries last for tens of thousands of cycles because of this. The point I was making was that with a fast charger, there is no need to babysit. I have a charger on my desk where I sit all day. If I plug it in for half an hour I get enough battery to last for days of use.

That said, no, I don't think most people should worry one bit about how they charge their devices. Just don't think that using a lower-powered charger is doing your device any favors.
 

snerkler

macrumors 65816
Original poster
Feb 14, 2012
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Thanks for all the replies guys, much appreciated. Some interesting info on battery 'maintenance' that I wasn't aware of too :)
 

muzzy996

macrumors 65816
Feb 16, 2018
1,119
1,068
The thing I've always wondered is if other companies such as those mentioned above are engineering the useful charge range limits into their products to maximize battery lifespan, are companies like Apple doing it for their devices as well?

At the end of the day the answer to that question isn't going to change my usage patterns but I do wonder whether people on either extreme are on target or worrying for nothing.
 

macduke

macrumors G5
Jun 27, 2007
13,480
20,591
Anything over 30W won't hurt it, but it won't help it. If you need to buy another adapter for faster charging at some point, Anker makes a 30W USB-C charger that is about half the price of Apple's 30W.
 

Buran

macrumors 6502
Oct 22, 2007
430
261
I just use my MBP's charger since I have it plugged in for plugging the laptop in from time to time for a recharge. It's easier to just leave one charger out than two. Well-made USB devices and chargers will only "take" what they need, so there's no harm to worry about.

I haven't measured which charger is faster as the one that came with the iPad is still packed in the box. Most likely, there's a noticeable difference but I'm not concerned about that.

Sometimes, I take the iPad to work and draw in Procreate if things are slow, so I plug it in to the PC there. I don't think the PC has the power to do more than maintain the battery's charge level, but that's fine with me.
 

BeatCrazy

macrumors 603
Jul 20, 2011
5,127
4,507
The thing I've always wondered is if other companies such as those mentioned above are engineering the useful charge range limits into their products to maximize battery lifespan, are companies like Apple doing it for their devices as well?

Of course Apple does this :) They’ll never tell us engineering secrets, but it’s obvious they have a handle on battery performance:
https://www.apple.com/batteries/maximizing-performance/
https://support.apple.com/en-us/HT208387
 

zhenya

macrumors 604
Jan 6, 2005
6,931
3,681
Anything over 30W won't hurt it, but it won't help it. If you need to buy another adapter for faster charging at some point, Anker makes a 30W USB-C charger that is about half the price of Apple's 30W.

It will take up to about 36W when connected to a 15V/3a charger.
 

secretk

macrumors 65816
Oct 19, 2018
1,494
1,229
The thing I've always wondered is if other companies such as those mentioned above are engineering the useful charge range limits into their products to maximize battery lifespan, are companies like Apple doing it for their devices as well?

Good point. I don't think that most smartphone companies are doing something. I have Sony phone. It can definitely allow me to charge my phone to 100 %. What my phone does though is having specific battery care routine that I use for charging at night. If I let it charging over night (which I prefer to not do often as I tend to use my phones for at least 3 and half/3 years) it checks my alarm. Then it spans the charging levels between the start time and the alarm so that it does not stay for long at 100 % (it would charge up to 90 % at regular time, then wait for an hour before alarm to continue charging). It also charges way quicker from 0 to 70 % compared to after that. This definitely prolongs my battery life. However then again I charge my phone every 4 or 5 days (software optimization of the phone itself, plus my own one of tweaking the Android settings and restricting some of the apps that I don't use enough to warrant them full access over stuff). As a result battery is never something I have issues with. My old Sony phone is now used by my mother after 2 and half years of my own usage and she has no issues with battery either.

So yeah some companies are starting to think about this. Nevertheless Lithium batteries are supposed to last up to 1000 charging cycles. What is true though is that charging often Lithium batteries with chargers at way higher voltage than what they battery needs would cause issues - namely expanding batteries than in the case of thin devices could even lead to not fitting anymore in the chassis of the device.

While I agree that 18 W is not the maximum for the iPad battery I also doubt that 87 W is optimum. I would suggest consulting with Apple on this.
 

zhenya

macrumors 604
Jan 6, 2005
6,931
3,681
While I agree that 18 W is not the maximum for the iPad battery I also doubt that 87 W is optimum. I would suggest consulting with Apple on this.

The iPad will not charge at 87W. The Apple 87W adapter will provide 9V/3a or 27W.
 

secretk

macrumors 65816
Oct 19, 2018
1,494
1,229
The iPad will not charge at 87W. The Apple 87W adapter will provide 9V/3a or 27W.

I hope that this is the case. And maybe the iPad Pro has this feature over the regular one. I have the regular one and I have specifically asked about this in the Apple store. They told me that they managed to damage a device by charging it with 30 W charger. I hope that it's issue only with regular iPads and does not affect you. However this is what I meant when I said that I suggest consulting with Apple :).
 

zhenya

macrumors 604
Jan 6, 2005
6,931
3,681
I hope that this is the case. And maybe the iPad Pro has this feature over the regular one. I have the regular one and I have specifically asked about this in the Apple store. They told me that they managed to damage a device by charging it with 30 W charger. I hope that it's issue only with regular iPads and does not affect you. However this is what I meant when I said that I suggest consulting with Apple :).

Whoever told you this was mistaken, which is not too surprising as the technical expertise required to work at the Apple store is not terribly high. This is nothing new - all USB device have had this capability from day 1. What is new is that only in recent years have iPads been able to accept more than 12W when made available.
 

TheRealAlex

macrumors 68030
Sep 2, 2015
2,988
2,253
Never Let the charge drop Below 20%
Do not charge with an over charger ie pushing too much voltage in too fast is bad for Lithium polymer cell packs.
Don’t put in a freezing cold place, ie outside in winter.
Use standard Apple charger from the box.
Or use Apple 30 Watt USB-C Charger for fast charging. Nothing stronger.
 

AutomaticApple

Suspended
Nov 28, 2018
7,401
3,378
Massachusetts
I've just bought the iPad Pro 11" and looked on google and have seen that I can charge it with my MBP's 87W USB-C adapter too which is great if I ever forget to take my iPad charger somewhere and have my MBP one. However, I can't find any info as to which would charge the iPad quicker and which one (in theory) should give it a longer lasting battery (if any).

So, which will charge the battery fastest, the bundled 18W or my MBP 87W adapter, and which (if any) will give it a longer battery life between charges?
I just use the charger that comes with the iPad, but that’s just me.
 

WesEdit

macrumors member
Nov 12, 2018
33
26
Never Let the charge drop Below 20%
Probably ‘flat’ charging in the range ~20-80% SOC extends the life of the battery minimally. But the question is, is it really important in today's short product lifetime? That can not be answered the same for everyone. I use my iPad's for a maximum of 2 years and I do not want to worry about the charge level at which I have to charge the device

Do not charge with an over charger ie pushing too much voltage in too fast is bad for Lithium polymer cell packs.
Apple allows to charge the new iPad Pro with a maximum of 15V and 2.4A. So, it is limited by Apple and you can safely use ie the Apple 61W or the 87W Power Adapter.

Use standard Apple charger from the box.
Why? They are at least twice as expensive. You can safely use third-party quality chargers. Just be aware that they support Power Delivery.

Or use Apple 30 Watt USB-C Charger for fast charging. Nothing stronger.
The fastest possible charging (~36W) you get with chargers that supports 15V/3A, which the Apple 30W Charger will not do. The iPP will also handle stronger chargers than the 30W one without any problems.
 
Last edited:

Steve121178

macrumors 603
Apr 13, 2010
6,463
7,171
Bedfordshire, UK
Charge normally with the adapter in the box or buy a 30w charger for fast charging, which is what I have always done.

Fast charging doesn't knacker the battery. If your battery shows serious decline then it's clearly faulty, so just take it to Apple & get it swapped for free.
 

DieselFiend1989

macrumors member
Dec 8, 2019
97
45
Fast reply on this two year old thread lol.

I already do, no questions here. Just perusing and merely wanted to point out to those who do have questions, maybe look at another thread if they want some accuracy. I was impressed at the diversity in the misinformation though.
 

BigMcGuire

Cancelled
Jan 10, 2012
9,832
14,032
Fast reply on this two year old thread lol.

I already do, no questions here. Just perusing and merely wanted to point out to those who do have questions, maybe look at another thread if they want some accuracy. I was impressed at the diversity in the misinformation though.
If you have the time I would love to know what information is bad. I don’t ask in sarcasm, in true interest as a battery fan. I can see some myself too.
 
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