Android Question Charging

[David Riley]

I have a Nexus 7 tablet used on permanent charge. After several years, unsurprisingly, the battery has ballooned, bending and pushing out the display. There is great risk of fire, explosion, and toxins.
To solve this I am reading the battery level (0 - 99) and switching the charger on via bluetooth. For testing it is on below 70 and off above 72.
What do people think would be the best setting ? I was considering on below 40 and off above 60.

 

[David Riley]

This has spiked my curiosity...

If I understand correctly so far, you are developing a device that is to be installed in a vehicle, right?
So my question is:
Will this device be continuous ON?! Like, even when the vehicle is parked overnight?

If the device does not need to be continuously powered on, and only needs to be on when the vehicle is in use (key in the ignition), then my advice is to take of the battery, and power the device through a circuit to allow for some safety feature for when the motor is started, and for a more "clean" way of powering it off.

Yes, it does have to be powered at all times. My existing product has no battery. The proposal was for a new device using an unmodified bought-in tablet or phone.

 

[David Riley]

I have had a Surface Pro 4 Windows 10 laptop on permanent charge for at least five years now with no problems in the belief that it is better (and easier for me) to do that rather than keeping running it down and recharging it. No problems at all so far, although as it is rarely used unplugged I don't really know if the overall capacity has reduced or not. But then if it is continually plugged in the ultimate capacity is irrelevant.

I would say that if you are worried about the safety aspects of Li-ion batteries then you should not be using one at all. If you are willing to use one then just use it as conveniently as possible and forget about any fancy charging/discharging/optimisation strategies - particularly if you can just plug it into vehicle power. If you are unlucky enough to get a bulging battery then you are just unlucky. I don't think you can rely on any strategy to mitigate the risk of that happening.

It is possible nothing can be done to improve the conditions for an unmodified device. What is needed is not the ability to switch off external power in software, as I have done, but to just stop the battery charging in software, so it can be left unused at an ideal storage state of charge and be available when external power is lost.

 

[agraham]

stop the battery charging in software, so it can be left unused at an ideal storage state of charge and be available when external power is lost.

The charging circuits in any modern tablet or phone will do just that already. Just leave it permanently on charge like I do with my Surface Pro.

 

[udg]

Since it seems acceptable for you to use a smartphone (o phablet), why not look for a device working with its battery removed and plugged through USB "recharger"?
I tried with an old phone of mine but it doesn't turn on if its battery is removed. I don't know if this applies to any phone on the market.
Obviously this kind of setup will turn off the device once the external power is removed.

 

[David Riley]

The charging circuits in any modern tablet or phone will do just that already. Just leave it permanently on charge like I do with my Surface Pro.

You cannot run from external power without getting a fully charged battery.

 

[agraham]

You cannot run from external power without getting a fully charged battery.

We're going round in circles here.

 

[David Riley]

We're going round in circles here.

Yes. My original post was about avoiding a fully charged battery.

 

[David Riley]

" What is needed is not the ability to switch off external power in software, as I have done, but to just stop the battery charging in software, so it can be left unused at an ideal storage state of charge and be available when external power is lost. "

I see Apple and Tesla have done this.

iOS 13’s new Optimized Battery Charging feature explained

If you want your iPhoneu2019s battery to hold its charge over time, youu2019ll enable this feature.

www.macworld.com

According to this article, part of the answer to my question is don't go below 30% or above 80%.
Hopefully we will get software access to control it ourselves in the future.

 

[saeed10051]

is it really a B4X related query???

 

[AnandGupta]

is it really a B4X related query???

Maybe Erel will move it to Chit-Chat, if deemed fit.

Regards,

Anand

 

[freedom2000]

I definitively would do this : https://www.google.com/search?q=cha....69i57j0l7.7362j1j15&sourceid=chrome&ie=UTF-8