effects of constant on off charging?

[Jdyount]

The standard not only protects against poor manufacturing, it ensures reliable user experience. These phone batteries are designed to be charged to their 100% setting and protected, under IEEE 1725 Standards, to prevent over charge and over current.

Now, in reading the article about prolonging lithium battery life on the battery universe website:

Sure you can increase the number of charge cycles in a battery by lowering the max charge level, but the info can be somewhat misleading because you should have more charge cycles if you decrease your depth of discharge. You can charge from 0% to 50% twice as many times as you can charge from 0% to 100% (50 X 2 = 100).

According to that article, if your depth of charge is 50% then you should get 1200 to 1500 cycles. I would guess that most users charge once a day and plug in to charge at night somewhere between 75% and 50% battery life. That is 3.3 to 4.1 years.... Even if you half that, you're still around the 2 year mark (which is where most would get a new phone). Now you are correct, if you do to math and factor out the lowering depth of charge gain, you can increase the amount charge cycles by decreasing the max voltage; but, this will only effect people who plan on using the same phone for 5 years. I would argue that your micro USB port won't last that long anyway.

The point I want to emphasize is that for 99.9% of people, they would be wasting their time monitoring the max charge, unplugging at 60% or 80% every time they charge. Under all but extreme use conditions, these phone batteries are made to exceed the 2 year cycle in which most people use a phone. Now I will concede that if you have a battery eating phone like the T-Bolt, the battery won't last 2 years, but thats not the fault of the battery.....

 

[Rizz1-2]

This has turned into one of the most informational battery threads I have ever seen. Thanks guys!

 

[gharkay]

The standard not only protects against poor manufacturing, it ensures reliable user experience. These phone batteries are designed to be charged to their 100% setting and protected, under IEEE 1725 Standards, to prevent over charge and over current.

Now, in reading the article about prolonging lithium battery life on the battery universe website:

Sure you can increase the number of charge cycles in a battery by lowering the max charge level, but the info can be somewhat misleading because you should have more charge cycles if you decrease your depth of discharge. You can charge from 0% to 50% twice as many times as you can charge from 0% to 100% (50 X 2 = 100).

According to that article, if your depth of charge is 50% then you should get 1200 to 1500 cycles. I would guess that most users charge once a day and plug in to charge at night somewhere between 75% and 50% battery life. That is 3.3 to 4.1 years.... Even if you half that, you're still around the 2 year mark (which is where most would get a new phone). Now you are correct, if you do to math and factor out the lowering depth of charge gain, you can increase the amount charge cycles by decreasing the max voltage; but, this will only effect people who plan on using the same phone for 5 years. I would argue that your micro USB port won't last that long anyway.

The point I want to emphasize is that for 99.9% of people, they would be wasting their time monitoring the max charge, unplugging at 60% or 80% every time they charge. Under all but extreme use conditions, these phone batteries are made to exceed the 2 year cycle in which most people use a phone. Now I will concede that if you have a battery eating phone like the T-Bolt, the battery won't last 2 years, but thats not the fault of the battery.....

Good points, all around. I agree with you that the IEEE standard ensures both safe batteries/chargers and reliable operation, but I am still of the opinion that the word "reliable" is used in this case to mean "won't explode in your face or fail prematurely for an average user". I did not see anything in the document about ensuring the battery will maintain a certain percentage of its capacity under specific conditions for a specific period of time. The stuff about preventing overcharge and overcurrent conditions and whatnot is more of an "explode in your face" issue than a "keep your battery going strong for many years" issue, in my opinion.

I absolutely agree with you that decreasing the depth of discharge will lead to better maintenance of battery capacity over more charging cycles. That said, I think you might be greatly overestimating the amount of battery life most people have left when they plug in at night (at least for those people using Android devices whose names don't end in Maxx). Also, here's something that I didn't realize was confusing me until just now: does depth of discharge merely refer to the percentage of battery life that is expended between charges, or is it the amount by which battery life percentage falls below 100%? I had always thought it was the latter, but now you have me wondering if I am wrong about that. If my interpretation is correct, then your example of charging 0%-50% would be much worse for the battery than the alternative of charging 50%-100%.

Regarding lowering the maximum voltage, I agree that it would be ridiculous to expect anybody to carefully monitor their charging status at all times and unplug when they reach 80% or whatever. But what I was suggesting is that there ought to be a setting to automatically limit that maximum voltage without the user having to do anything other than choose "battery longevity mode" over "maximum run time mode" or something along those lines. For example, Franco's GNex kernel has a battery saving option that allows you to set a maximum percentage above which the battery will stop charging with no intervention from the user. The optimum conditions for the battery should, as I understand it, involve both preventing deep discharge and limiting the maximum voltage. If you only discharge your battery by 5% every time but that range fits in between 95% and 100% of the battery's full charge capacity then you're avoiding the deep discharge, but your're still sitting in that high voltage range.

I don't think a USB port should have any trouble lasting for five years. I don't have a source handy, but I believe that micro USB ports are built to withstand a minimum of 10,000 insertions. That means you could plug/unplug your phone more than 5 times a day for 5 years, so I doubt it would fail mechanically in that period of time. Of course that doesn't account for other factors like corrosion, etc. But hey, that's what that stupid little flap on the bottom of the DNA is for, right?!

 

[Jdyount]

The study rates number of cycles based on depth of discharge (dod) and included incremental percentages. My interpretation would be that they were starting from 100% charge, the measuring dod based on percent from there. My example was to show simply that one full charge cycle and 2 half charge cycles are essentially equivalent. Now, there would be a slight difference in charging from 0% to 50% and charging from 50% to 100% because the latter is taking you to max.

As to the USB, I do agree, in rated use, 10,000 insertions sounds right, but that doesn't account for life. For kids or dogs knocking your phone off the table while charging, for trying to get the cable in the right way in the dark, ect.... In my personal use, I've found after about two years, the micro usb port becomes wore (cables are loose, sometimes doesn't charge).

Having a customer kernel is a great option and having those battery mode settings are great and I'm sure they help, but not everyone roots.

As to battery life, I would like to see stats on that. I can tell you with my DNA, unless I've play games for a couple of hours, I haven't been below 70%. Right now (8 hour day so far), I'm at 87%. With my T-bolt, it was dead at 10 hours no matter what. My wife charges her iPhone (yes I know, boo) every other day.

You have had very good points, and I appreciate the discussion.

 

[jamdmyers]

Ditto on the great battery info from the posters, but in regards to the op who are 'they keep telling me' ... just charge overnight and use the phone, many people won't need a recharge during the day, of course some will but then plug it in.. Power Management has alot to do with power consumption and HTC seems to have done a fair job at it this time.

 

[gharkay]

As to the USB, I do agree, in rated use, 10,000 insertions sounds right, but that doesn't account for life. For kids or dogs knocking your phone off the table while charging, for trying to get the cable in the right way in the dark, ect.... In my personal use, I've found after about two years, the micro usb port becomes wore (cables are loose, sometimes doesn't charge).

Fair enough. I don't have any kids or dogs to deal with just yet, so hopefully my USB port will hold out for more than two years!

Having a customer kernel is a great option and having those battery mode settings are great and I'm sure they help, but not everyone roots.

I absolutely agree that not everyone roots or installs custom kernels. That's why I would like to see options for maximizing battery longevity included as standard, albeit advanced, features.

As to battery life, I would like to see stats on that. I can tell you with my DNA, unless I've play games for a couple of hours, I haven't been below 70%. Right now (8 hour day so far), I'm at 87%. With my T-bolt, it was dead at 10 hours no matter what. My wife charges her iPhone (yes I know, boo) every other day.

I have only had my DNA for a few days now, but I have resisted the urge for the last three days to charge it during the day to see what would happen. The result is that the battery has been below 10% by the time I plug it in when I go to sleep after being unplugged for around 15 hours. I have been using it quite a bit, but nothing too crazy. On average I've probably been sending around 5 emails, writing around 15 text messages, and reading things for around an hour. You must use it very lightly to have 70% left at the end of the day! I wish that HTC hadn't removed the screen on time listing from the battery usage information as that would help me figure out how much time I spend actively using the phone.

You have had very good points, and I appreciate the discussion.

Likewise!

 

[PsYcHoNeWb]

A lot of very good points here and a lot of stuff that had been said before but good to have it come up again as always. I personally believe that you should enjoy your phone and not worry so much about your battery.

I noticed as well that my phone gets slightly hot from wireless charging overnight but after about 2 minutes it was normal. Didn't concern me and didn't seem to cause any issues. While there is always a constant discussion about how to properly charge and discharge the bottom line is that HTC and every other cell phone manufacturer for that matter built the phone for our enjoyment. Enjoy it and don't worry so much about the battery.

If it was that much of an issue they would say a proper procedure so they don't have to worry about warranty claims constantly. I'm sure they have limitations in place so that nothing can damage your battery from normal usage or charging. That being said, overheating could potentially be a problem but slight heat I don't see a problem. Laptops get hot like that all the time and they usual are fine.

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