What are the current ideas behind quick charging and battery life/health?

[reconrey]

Well, I just got a new phone and it included a Turbo Charging power brick (phone is a Moto G4) that seems to work by bumping the voltage up to 9v at 1.2a or 12v at 1.2a.

That being said, what are the current thoughts on how this will impact the battery. I have heard that it will lead to poor battery health, poor life for that charge, or nothing noticeable at all. Also, will there be any negative effects of leaving it on the charger overnight (I have also heard people stating both sides on this too). Is there any actual research that has been done on this, or will the differences not be noticeable at all?

My previous phone was a Droid Bionic (almost 5 years old) and I was on my 4th battery. I constantly had the phone on the charger when I was home and I am worried that the same will happen to this phone but I will not be able to easily change the battery if I do not treat it right.

 

[Sergiusz Jasper]

I only use fast charging when absolutely needed otherwise I use a slow charger over night.
I see no need to have it on a charger all the time just at night...cos if I need to top up I'll fast charge.

 

[reconrey]

Now, is that just because you think that will be better for the battery, or is it something you actually researched?

 

[Sergiusz Jasper]

Now, is that just because you think that will be better for the battery, or is it something you actually researched?

I would say better for battery, fast charging can cause heat and that kills battery faster.

 

[reconrey]

So, considering heat is the enemy, would it be wise to get a lower powered charger that may only put out something like 0.25C (or even less) and let it sit overnight and charge? Also, what about lowering the voltage over lowering the current? Would a 3 volt charger be a good idea (assuming somebody makes one)?

 

[Sergiusz Jasper]

Well I use a iPhone cube charger cos it has low output and works great as a slow charger, but yes any regular charger will work.

 

[reconrey]

I have a charger from an old camera that outputs 5v at 0.5a that I think I may turn into my overnight charger. I just did a full charge with the turbo charger and I do seem to be loosing battery a bit faster than I did yesterday when I fully charged it with a 0.75a charger.

 

[Mooncatt]

So, considering heat is the enemy, would it be wise to get a lower powered charger that may only put out something like 0.25C (or even less) and let it sit overnight and charge? Also, what about lowering the voltage over lowering the current? Would a 3 volt charger be a good idea (assuming somebody makes one)?

Lithium batteries can handle a fair bit of heat, so that's usually not an issue unless you have something else going on. The charge voltage also isn't as big of deal as amperage, but phones don't even charge at a full 1C rating as it is. Lithiums can handle 1C fine, with some specialty batteries (I.e. Those used in R/C hobbies) that can charge 3-5C safely. For our uses, it's nothing to worry about.

Using a lower voltage charger wouldn't work, either. A full Li-ion battery is 4.2V, and some high density batteries going 4.3V. If you charge at 3V, the phone would either not charge or simply drain. Even a dead battery is above 3V. Remember, the charging voltage always has to be higher than the battery voltage. Think of it as filling a bucket from a water tower. The height difference would be the voltage difference. If you put the bucket far below, it'll fill quick. If it's about the same height, it'll fill more slowly. If you put it above, nothing happens.

Leaving it on a charger overnight can hurt it over time. Li-ion's don't like being held at a full charge. Conversely, they don't like being empty. Either extreme leads to accelerated chemical breakdown, which is why new batteries are shipped with a partial storage charge.

www.batteryuniversity.com has a ton of info on proper charging and care of different types of batteries.

 

[reconrey]

Alright, that makes sense. So, I'd assume that the added heat from using the phone while charging could negatively impact the battery, so the phone should be powered down or idling when charging, correct? Does the charge current have any negative effect on the battery life? In my previous post I mentioned that the battery seemed to be going down faster, however I am currently sitting at just under 50% from that same charge yesterday, so it may have just been the first few percentage points that bled off quicker, which makes me a bit more unsure on that.

 

[kramer5150]

FWIW I have not noticed any detriment to fast charging. I have a Qi charge case back on my LGV10 (which is the same as using a 5V slow charge) so I end up using that most of the time.

 

[Mooncatt]

Alright, that makes sense. So, I'd assume that the added heat from using the phone while charging could negatively impact the battery, so the phone should be powered down or idling when charging, correct? Does the charge current have any negative effect on the battery life? In my previous post I mentioned that the battery seemed to be going down faster, however I am currently sitting at just under 50% from that same charge yesterday, so it may have just been the first few percentage points that bled off quicker, which makes me a bit more unsure on that.

Phones have the ability to throttle the charge rate. If the phone is getting hot, it'll slow the charge to help prevent excessive heat. Sometimes you may even see the charge level go down, depending on what you're doing. I wouldn't be too concerned about heat damage, as Li-ion batteries are typically good up to about 150°F on a healthy cell.

I don't think the charge rate would have any effect on charge capacity. Chargers work in stages, and the last two are reduced rates to prevent electrical "spill over." Going back to my bucket example, it's like slowing down the water flow at the end to keep it from splashing out while it's topped off. All chargers are like this, even the quick chargers. Not sure what to make of your experience. If it just one day, that's not enough to tell. You'd need to use the slower charger foot a while to see if a pattern shows up.

 

[reconrey]

Phones have the ability to throttle the charge rate. If the phone is getting hot, it'll slow the charge to help prevent excessive heat. Sometimes you may even see the charge level go down, depending on what you're doing. I wouldn't be too concerned about heat damage, as Li-ion batteries are typically good up to about 150°F on a healthy cell.

I don't think the charge rate would have any effect on charge capacity. Chargers work in stages, and the last two are reduced rates to prevent electrical "spill over." Going back to my bucket example, it's like slowing down the water flow at the end to keep it from splashing out while it's topped off. All chargers are like this, even the quick chargers. Not sure what to make of your experience. If it just one day, that's not enough to tell. You'd need to use the slower charger foot a while to see if a pattern shows up.

I have been reading at that battery university site you linked earlier and I found a couple interesting snippets on the charging lithium ion batteries page.

Increasing the charge current does not hasten the full-charge state by much. Although the battery reaches the voltage peak quicker, the saturation charge will take longer accordingly. With higher current, Stage 1 is shorter but the saturation during Stage 2 will take longer. A high current charge will, however, quickly fill the battery to about 70 percent.

Additionally,

Some lower-cost consumer chargers may use the simplified “charge-and-run” method that charges a lithium-ion battery in one hour or less without going to the Stage 2 saturation charge. “Ready” appears when the battery reaches the voltage threshold at Stage 1. State-of-charge (SoC) at this point is about 85 percent, a level that may be sufficient for many users.

I'm not sure if the included charger will fall into the "lower-cost consumer" category, but this information does seem to be suggesting that these fast chargers can result in a charge that does not have as much runtime as a slower charge. Also, the How to Maximize Runtime article states that you should charge between 0.5C and 0.8C. The turbo charger that I have is only charging 0.4C to 0.53C which seems like to should be fine, aside from the increased voltage used. The only thing I am not too sure about now is if charging at an even lower current will cause issues to the battery. It doesn't seem like it should have a negative effect however. Also, I found this site which states that when charging at 0.18C the cell will be full by the time the battery reaches 4.2v, which seems like it would be the most efficient (albeit rather slow) way to charge the battery.

 

[Mooncatt]

I've never used (or even seen, for that matter) a USB charger with a "ready" light on it to indicate it's finished. I've seen AA type rapid chargers that do this, though. With phones, there's the screen charging indicator to show the charge level. So I don't see how this could be an issue in what the capacity is at full charge. Even if an el-cheapo charger indicated full, the phone would indicate the true charge state.

As for the charge rate, the slower the better. For practical purposes, I don't think there's anything to be gained from going all the way down to .18C. I'm sure on paper you'll see a change, but there's so many other variables in real world usage that you'd never be able to tell. Plus there's the convenience trade off.

I use phones with removable batteries, so I'm not quite so picky with my charging habits.

 

[reconrey]

Yea, I think that removable batteries is the way to go. I went for this phone solely because I was able to get it for so cheap with the Amazon discounts, however I think that it may still be possible, just not practical, to remove/replace the battery in this phone. As I mentioned I went through nearly 4 batteries on my old phone in its nearly 5 years of life (but I had very bad charging habits, like leaving it charging for 18 hours or more), so I plan to play it a bit more carefully with this phone. Also, might I ask, what phone do you currently have? The only company that I can think of that is sticking with the removable batteries is LG and I have heard some bad things about their phones.

That being said, for now I think I will stick with using my 0.5a camera charger overnight, which should be giving it about 0.17C. Also, if my math is correct, I believe that it will take 6 hours to charge from a completely dead battery, so considering I only bring it down to 20-30% it should be done in just under 5 hours (once again assuming that my math is correct and that it is being transferred with perfect efficiency), so it should not sit at 100% for too long.

Also, I just got my Raspberry Pi Zero in the mail today and I think I may be using it to create a little charge timer for the phone so it never quite makes it to 100%, just not entirely sure how I want to approach this yet.

 

[Mooncatt]

I do have an LG G4. I know it has had boot loop issues, and had mine replaced already for it. I haven't heard much one way or the other on how the other models are holding up. I have Verizon's extended warranty, so I'm ok on that front.

Before this, I had two HTC M8's that had two USB ports fail, and it was a non-replaceable battery. So I didn't even have the option of an external charger to keep things going otherwise.

Before, I also had the Bionic. Like you, I killed the stock battery prematurely from leaving it plugged in all the time. I replaced it with a 4000mAh OEM extended battery and changed my habits. I still keep it as an emergency backup phone in storage charge. It lags like no tomorrow, but the extended battery was still good as new after over a year in storage. I used it when my second M8 failed and hadn't got the G4 yet.

 

[reconrey]

I would like to stick with phones that have removable batteries, but upgrading through Verizon is a bit sketchy as I would rather keep my grandfathered unlimited data plan and I would rather not be paying full retail for a flagship phone. I figure with a phone that was this cheap I would be able to upgrade it before the battery goes, but if it comes down to it, it doesn't look like it would be too hard to teardown and remove it. In the meantime, I will try to baby the battery to prevent that from happening.

Anyways, thanks for all your help, you have given me a lot to think about.