wireless chargers

Does anyone here use a wireless charger? I was thinking about getting a Google Pixel Stand Fast Wireless Charger which gets you up to a 10W charge for the Pixel 3. I figured it would eliminate the number of times I'd have to use the USB-C port for charging.

However, my battery app recommends not charging above 80% because it increases the wear on the battery when you charge it fully.

Does anyone know if these wireless charging stations allow you to set a maximum charge level so that you can stop charging at a certain point? I'd like to be able to leave it on the charging stand constantly without having it constantly trying to charge the phone to 100%. I'd rather have it charge to 80%.

Wireless chargers take longer to charge the phone, but otherwise do the same job.

A wireless charger works exactly the same way as a wired one - except wirelessly. No additional features, such as limiting the max charge. For that, you'd need something that tied into the hardware of the phone and the charger - I don't know if that exists.

Besides, modern smart phone batteries are much smarter than before and I am not sure that it really makes any difference to limit charging to 80%.

Jeff Peterman wrote:

A wireless charger works exactly the same way as a wired one - except wirelessly. No additional features, such as limiting the max charge. For that, you'd need something that tied into the hardware of the phone and the charger - I don't know if that exists.

Besides, modern smart phone batteries are much smarter than before and I am not sure that it really makes any difference to limit charging to 80%.

I have battery apps on our phones, and the app recommends 80%.

Also, my wife charges her phone overnight and her Pixel 2 battery is at 30-40% original capacity, forcing us to get her a new phone. My Pixel 3 that I try to charge until 80% is still at 80%+ original capacity. Small sample size of course.

if you do any research on Lithium batteries and the best charging conditions you will see that this is extremely complex. Higher end Lithium batteries are full of sensors and circuitry that do things like monitor battery temperature and charge relative to capacity and regulate the charging pattern to keep these under control and maximize battery life.

In many cases, when people say that their phone's battery don't last as long now as before it is because of accumulated background tasks - they have added more and more apps, or apps have started doing more in the background - so the battery usage has gone up. Sometimes, doing a "factory restore" and then reinstalling apps will help especially if you are careful and only reinstall apps that you actually use.
As for the "battery app" you mention, unless it came from Google and was designed for the Pixel phone you are using then I wouldn't trust it - it has to have been designed for your exact battery hardware, and communicate with the battery's on-board electronics, to be of any value.

Jeff Peterman wrote:

if you do any research on Lithium batteries and the best charging conditions you will see that this is extremely complex. Higher end Lithium batteries are full of sensors and circuitry that do things like monitor battery temperature and charge relative to capacity and regulate the charging pattern to keep these under control and maximize battery life.

In many cases, when people say that their phone's battery don't last as long now as before it is because of accumulated background tasks - they have added more and more apps, or apps have started doing more in the background - so the battery usage has gone up. Sometimes, doing a "factory restore" and then reinstalling apps will help especially if you are careful and only reinstall apps that you actually use.
As for the "battery app" you mention, unless it came from Google and was designed for the Pixel phone you are using then I wouldn't trust it - it has to have been designed for your exact battery hardware, and communicate with the battery's on-board electronics, to be of any value.

I'm using AccuBattery.

Here's an explanation on how they estimate stuff: https://accubattery.zendesk.com/hc/en-us/articles/210224725-Charging-research-and-methodology

Whether they are taking the right approach is above my pay grade.

First, nearly everything cited is from more than 15 years ago, and there have been big advances in battery design and battery electronics since then. Second, and key, is the statement:

"Charging is controlled via your device's battery charge controller, which is a chip that carefully controls the voltage and current to charge your battery as fast as possible within the safety limits. Apps cannot influence this process."

The statement points out my biggest concern - apps can't really do much. All they can do is monitor and display the battery usage/charging.

The reality is that the battery's electronics may already limit max charge to something less than 100% than the full capacity of the battery, and they may already have smart features that regulate the charging rate to protect the battery while maximizing charging speeds.

As an example, I have a Samsung Active watch that charges really slowly not matter which charger I use because its electronics limit the charging rate - and it will stop charging and report a charging error if I use some chargers that try to bypass the limit.

Jeff Peterman wrote:

First, nearly everything cited is from more than 15 years ago, and there have been big advances in battery design and battery electronics since then. Second, and key, is the statement:

"Charging is controlled via your device's battery charge controller, which is a chip that carefully controls the voltage and current to charge your battery as fast as possible within the safety limits. Apps cannot influence this process."

The statement points out my biggest concern - apps can't really do much. All they can do is monitor and display the battery usage/charging.

The reality is that the battery's electronics may already limit max charge to something less than 100% than the full capacity of the battery, and they may already have smart features that regulate the charging rate to protect the battery while maximizing charging speeds.

As an example, I have a Samsung Active watch that charges really slowly not matter which charger I use because its electronics limit the charging rate - and it will stop charging and report a charging error if I use some chargers that try to bypass the limit.

From what I read on their page, I don't think they disagree with any of your statements. In fact I think they said something very similar.

I think what they've done is create an algorithm for measuring battery health based on data the app collects in each phone during charging. In other words, the app does not control the actual charging process. The phone and charger do. But the app can measure what is happening during charging, and this data is used to plot each battery's projected health.

"We've gathered millions of data points on multiple devices to model the battery wear. As every battery has their own discharge voltage profile, we've verified that we can use the discharge curve to map percentages to an "idealized voltage" which then is used to feed the charging from x to y causes z cycles of battery wear algorithm. The absolute voltages can differ between devices, but the general shape of the discharge voltage curve is bound to how Lithium-ion batteries behave as a class and are comparable between devices."

But that is within the limits of what is provided by the hardware. For example, the hardware may only let the battery charge to 80% of full capacity and turn off the phone when it gets to 10% capacity, and the app will see that 80% as 100%, and the 10% as zero, so it will set the window much narrower than it needs to be.

I can see a good battery app having some value, but mainly for identifying battery drain rates so that you can tell what really eats up the battery.

Jeff Peterman wrote:

But that is within the limits of what is provided by the hardware. For example, the hardware may only let the battery charge to 80% of full capacity and turn off the phone when it gets to 10% capacity, and the app will see that 80% as 100%, and the 10% as zero, so it will set the window much narrower than it needs to be.

I can see a good battery app having some value, but mainly for identifying battery drain rates so that you can tell what really eats up the battery.

The app shows Design Capacity (which seems to be the official manufacturer's stated capacity) and Estimated Capacity (which is probably their estimated actual capacity based on battery health).

I don't really understand myself what the discharge voltage curve implies about battery health, but it doesn't seem to be based on whether the phone is charging to its Design Capacity. Their method seems to be based on measuring the nature of the battery drain during power usage.

I have used them for years with Samsung phones, as has my wife. Both of us put our phones on wireless chargers at night - slow charging doesn't matter.

My Samsung watch can only be charged wirelessly - it is very picky about chargers to make sure that the charger will not damage the watch.

Not about wireless charging specifically but NYT just did an article about battery life

https://www.nytimes.com/2020/09/04/smarter-living/phone-charging-advice.html

There are MANY factors involved, including how close to 100% you charge, how low to 0% you let it go, how quickly you charge, the temperature, and the electronics built into the battery charging circuit (which can be very "smart"). All these combine to make it impossible to predict how any one action will impact battery life - except for one: overheating will damage the battery structure and ultimately reduce battery life.

Charge the phone in a way that works best for you - if you spend a lot of time worrying about "optimization" you will be spending a lot of effort for a tiny (if any) improvement.

But avoid overheating.

It is overheating of the battery. The phone itself my or may not get pretty hot (hot to the touch) depending on the design.