cell phone charge rate, temperature and longevity

sbslider · 2018-11-21T00:43:23.000Z

Recently purchased a moto G6 which has a 3A max charge capability. The battery is 3A hr, so this is basically 1C peak.

This webpage says a full charge takes 109 minutes to go from 0% to 100%.

The phone definitely gets warm when charged with 3A,I was going to try to measure temperature rise of the case but I can’t find my thermocouple.

Anyway, I am thinking I can cool the battery (enough?) to counteract the internal heating my charging my phone in the cool of the morning. Outside temperatures are 8-12 degrees Celcius this time of year, and I can easily plop my phone between the window and screen while charging.

What is a bigger contributor, temperature while charging or staying within 25% to 75% charged? I try to keep my phone between those limits as measured by the phone itself, as I don’t have access to the battery voltage. Any idea how the numbers on battery U compare to what a phone tells you?

I have looked at battery university, and the famous charts of number of charge cycles vs depth of discharge. 20% depth of discharge gets a whopping 2000 cycles, but this is really equivalent to 400 cycles at 100% depth of discharge, so why bother using only 20% of the battery and charging constantly. Likely to wear out the connector instead, and needing a new phone anyway.

To summarize, curious to hear inputs on keeping a phone cool while charging at 1C rate to offset any degradation that could be caused by charging at 1C rate.

BlueSwordM · 2018-11-21T01:19:28.000Z

What you need to take into account is:

1.1 Temperature
1.2 State of charge
2. Charge speed

All of them are really important, but some factors like charge speed and temperature are easier to control.

- You want to use fast charging tech like QC 3.0 and USB PD 2.0+ as few times as possible, like with your G6s 15W fast charging. Not only does fast-charging hurt cycle life just because it charges the cell faster, but it can also create noticeable heating due to cell internal resistance and the buck converter inside of your cellphone.

Basically, you want to charge from a regular USB power supply without fast charging, like from a 2A USB power supply, which will usually give out 7,5W-10W max depending on your phone, which will help out with cycle life quite a bit, since you won’t be pushing your phone’s battery quite as much, and less heat is produced. Or just charge from a computer’s USB port.

You don’t need to always quick charge your phone, do you? Haha

- When charging, keep on your phone on a solid surface. The surface will act like a heatsink, and spread out the heat generated during fast charging, which can help during the morning for example if you need a few more %.

- Here’s the more complicated part now, in relation to keeping your phone between 20–80/90 as seamlessly as possible:

If you have an unlocked phone, you can try unlocking the bootloader, and getting root access to your phone. This will allow you to install a root app called Battery Charge Limit:

f-droid.org

Battery Charge Limit | F-Droid - Free and Open Source Android App Repository

Stops charging at a desired level

This will allow you to limit the max charging voltage on your phone. This can help immensely in terms of cycle life, and even fast charging more often.

I personally keep it at 86% for optimal balance between capacity/cycle life, which has helped out a ton of people in my entourage keep their phone’s battery healthy, even with quick charging.

- Final tip: If you can activate battery saver at a certain percentage, put it at 20%. This will help.

TLDR:

1. Fast charge your cell phone as few times as possible. Use a regular 2A charger, or a computer’s USB port.

2. Keep your phone on a surface while fast charging. This will help it dissipate the heat produced.

3. Limit your max charging to 80-90% charge. This will help. If you have access to root, with an unlocked phone, you can install this app to automate it, and make it as seeamless as possible:

f-droid.org

Battery Charge Limit | F-Droid - Free and Open Source Android App Repository

Stops charging at a desired level

4. Keep your phone above 20% preferably, and above 15% if you really need it.

sbslider · 2018-11-21T01:49:16.000Z

Thanks for the tips BSM. I definitely don’t need to charge my phone quickly in general, and was hoping keeping it cool during quick charge would offset any degradation quick charging might cause, but it sounds like it won’t.

As far as rooting my phone goes, I did that with my last phone and regretted it. Never got updates, and it after a couple years did not work very well. Most folks get a new phone every year or two, but I like to hold onto mine. My first phone lasted 8 years, second one only 4 though. Would love to get at least 4 out of this one. If you have advice as to how to install the battery charge limit app without loosing access to updates, I would consider that. Meanwhile I’ll poke around and see if there are others that do the same thing and install easier.

Thanks!

BlueSwordM · 2018-11-21T01:58:27.000Z

Well, the difference now with rooting is that it’s literally systemless. Have you heard of our lord and savior Magisk?

I’ve had no problem with it persisting with updates, unlike SuperSu.

And keeping it cool will help. It’s just that it is easier to keep a phone cool if it isn’t fast charging.

Barkuti · 2018-11-21T02:13:36.000Z

sbslider:

…

As far as rooting my phone goes, I did that with my last phone and regretted it. Never got updates, and it after a couple years did not work very well. Most folks get a new phone every year or two, but I like to hold onto mine. My first phone lasted 8 years, second one only 4 though. Would love to get at least 4 out of this one. If you have advice as to how to install the battery charge limit app without loosing access to updates, I would consider that.

…

I've been running rooted systems since nearly 3 years ago, and I am quite happy with them. First of all, updates may not be a good thing. I used a rooted Moto G 2013 from early 2016 until April 2018 when I got a Zuk Z2 Pro, never missed one of those “install this update now because fuck-thee” stuff, and its optimized debloated 5.1 ROM was super fast. There even were Marshmallow custom ROMs for the Moto G 2013, something unseen from Motorola.

Now running AEX 5.7 Oreo 8.1 in the Zuk, runs like cream. Custom ROMs like this one have automatic updates, though I do not care. If I want to update I usually peek at XDA Forums first to check what's going on with the updates and other ROMs, to see if I want to update or even download a new ROM of my liking and install it via recovery.

Rooting may not be for uninformed users, though I have a friend which is now running a rooted custom ROM and is happy.

For me this is about who has the upper hand in my systems, and it can only be me.

Cheers ^:)

sbslider · 2018-11-21T03:02:32.000Z

BlueSwordM:

Well, the difference now with rooting is that it’s literally systemless. Have you heard of our lord and savior Magisk?

I’ve had no problem with it persisting with updates, unlike SuperSu.

I have not heard of Magisk or SuperSu. I don’t recall what I used, but I never got any real additional functionality out of it. Maybe it was just a lousy phone to begin with. I will contemplate a root to be able to cut off charging at 80% or so, until then I will do it manually.

I did find an article was useful.

oto · 2018-11-21T06:10:11.000Z

I try to keep my phone between those limits as measured by the phone itself, as I don’t have access to the battery voltage. Any idea how the numbers on battery U compare to what a phone tells you?

There are apps for measuring battery voltage. For example this

Barkuti · 2018-11-21T08:14:32.000Z

3C Battery Monitor Widget, probably the best battery monitoring application in Android. I always have a small widget in my desktop reporting battery voltage, percentage and current in/out. Graphs all those parameters and more.

Yes, Magisk owns. :THUMBS-UP:

eas · 2018-11-21T08:29:58.000Z

Rooted systems are great, until malware burns up your battery mining cryptocurrency

Barkuti · 2018-11-21T09:07:16.000Z

Battery mining cryptocurrency?

Those who claim a rooted system is insecure are just spreading misinformation. A rooted system can be insecure to those who are trying to milk the cows turning smartphones into their cash registers, G00gl€ and other powers that be ;-) you know. This is the reason to spread misinformation. But they can only lick my arse if I will.

My smartphone is not a toy at the service of others, rather it is a handheld computer at my service which happens to do phone calls and other stuff. ;-)

Cheers ^:)

thisnameisvalid · 2018-11-21T09:39:41.000Z

I have a G5S Plus and only use the fast charger when I really need it. If I’m just charging normally I use a standard 1A power supply but if I forget to charge my phone and find out in the morning, I’ll use the fast charger.

EDCba · 2018-11-21T14:26:24.000Z

Beware condensation if you’re charging it near outdoors.

sbslider · 2018-11-22T00:51:27.000Z

So I have been doing some reading today and as stated by BSM, two battery killers are letting a battery stay charged at full voltage and it getting hot. Fast charging makes the battery hot, so better to not do that as well.

But I have not found any real concrete data on battery voltage being too low. Obviously one should stay above the 2.5 - 3.0 V cuttoff, but is going down to 3.3V on a relatively lightly loaded (C/5 to C/10) battery going to cause long term degradation?

Barkuti · 2018-11-22T02:45:25.000Z

The battery voltage too low thing is just a stupid myth bred by bright sparks. In laptops, tablets and smartphones the battery is managed by its internal dedicated circuitry, and those devices will never let their cells' voltages to drop low since they are set to cut-off quite high, generally well above 3V. The lowest figure I've ever seen in a smartphone (in my old Moto G 2013) was ≈3.17V. I do not mind draining them all the way down, and my batteries live for thousands of cycles. Literally.

Even down to 2V is considered safe with regards to cell reanimation.

sbslider · 2018-11-22T04:32:07.000Z

I found this thread which discusses the subject of charge and discharge voltage in some detail.