From my experience handling mobile devices, when the battery on screen reaches 0% and the device cuts out, there is in practice a significant amount of charge remaining in the battery. This is to ensure that there is enough charge remaining to prevent data loss on the device for however long until it can be recharged.
However, if you leave it in this state for a long enough period without getting it to a charger the device then enters a deep discharge state.
This is what I'm trying to find out more about, and if anybody is knowledgeable about this, I would particularly like to know about
-How long it takes to reach this stage on any devices you have experience with
-What effects it has in terms of data loss and device functionality
-On iPhones and newer Samsung obviously you can't take out the battery, but on many other models you can remove the battery from the device. What effect does this have after however much period of time?
Just for a little background, I had a very old Samsung phone (over 15 years old) that had had no battery inserted into it for well over 10 years, then after some 10 minutes of connecting it to a charger it powered on and all the data was there exactly as it was before and the device worked like new.
However a relatively new model iPhone was allowed to power down to 0% and left in that state for around a year. It was a headache trying to get it charged again and when it finally did power on much of the data was corrupted.
Preserving the data doesn't rely on having the device charged or not.
For devices which you can't easily remove the battery, dismantle the phone using a phone dryer, alcohol and some dedicated tools. It is a waste of time trying to deal with a dead battery.
Nearly all modern mobile devices are using eMMC memory which is essentially the same as an SD card soldered onto the PCB. Older devices may have used NAND flash or other ROM type memory. All are non-volitile and will safely store data for many years with minimal bit degradation. NAND is probably the most susceptable to this sort of memory loss, but generally, has a fair amount of redundancy in the data storage allowing for error correction in the end.
I have seen some devices that if the battery becomes totally discharged and it sits that way for a while, will refuse to charge later when plugged in. My wife has a nice Macbook laptop which I got free from a customer and that was the only actual issue with it. Probably the device requires some relaying to happen and keeps some charge to activate the charging cycle.
Also, with any battery the voltage will drop as it's discharged. At a certain point the voltage will be lower than can be safely used by the device without possibly damaging the components. So I'd suspect that's a big reason why they shut off when they do. I already notice that when my Galaxy Note is below 10% it'll get really slow (probably having to reduce frequency to maintain stability).
More or less with modern Li-Ion batteries a minimal charge is needed to initiate charging 😯
It does sound "queer" or counterintuitive, but it is simply how they work, the charging controller prevents recharging if the current voltage is too low, the phenomenon is usually called "sleeping", in some cases they can be "awakened" but if the voltage has gone too down it is risky to "boost" them in order to "awaken" them
http//
jacla<