Some observed progress in Lithium-Ion Batteries.

I have posted before about Lithium-Ion batteries. My relatively new Samsung Galaxy S9 Smart-Phone possesses one, and seems to have better battery performance overall, than my old Galaxy S6 did. Also, both these phones had a sensor chip which measures battery voltage. I use an Android app called GSam Battery Monitor Pro, to get occasional glimpses of what my battery is doing, and without such a hardware chip, the app would not be able to provide meaningful information. On my Galaxy S9 phone, the battery has a voltage of ~4.2V once fully charged, and I’m assuming that to plug the phone in just keeps it connected to a constant voltage source…

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On my previous, Galaxy S6, when fully charged, the battery had a voltage of ‘only’ ~3.7V. And so one strategy which Samsung could be using to increase battery life, would simply be to charge the same battery technology to a higher voltage. However, usually, doing so would only result in the battery catching fire. And so, some improvement in the actual design of the battery had to take place, so that it could be kept charged to 4.2V, and not suffer any immediate damage.

Dirk

 

The GSam Battery Monitoring App

On my Android smart-phone, I have the third-party “GSam” battery monitoring app installed.

This app can be a useful tool, to determine which other apps are causing the greatest battery drain. It gives very detailed information about the battery and its charging behavior.

Further, this app will state the battery voltage – in addition to the percentage charged – any time it is clicked on. This is where I obtained the numbers I used in this earlier posting.

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At lower current-levels of battery-drain (-13mA), this same app showed the battery as 96% charged, but with a voltage of 4.24V . The app continues to run in the background, when the phone is asleep, and when the phone may be drawing much less current than it does with the display on. Then, after we wake up the phone, this app initially displays with its remembered values, until a few seconds later, the app-data updates.

(Edit 12/14/2016 : In the case of a soldered-in battery, it would make perfect sense if the O/S of the device computed the State Of Charge as a linear function with two fixed voltage end-points, as well as to compensate for the amount of current drawn, as if the battery simply had an assumed series-resistance. This is because a soldered-in battery is not assumed to be changed. However, multi-pronged battery-packs also exist, which possess internal chips. Those could be exchanged easily by the user.)

(Edit 12/12/2016 : Actually, this app does not tell the phone, what the State Of Charge of the battery is – the Percentage Charged.

And so there will be a scattering of relationships, between voltages as measured by the device, and percentages. However, one concept which intrigues me, is that if each battery-pack has 4 prongs, there is no way for me to rule out, that 1 prong could be for discharging, while 1 prong could be for charging.

If that were the case, then the charging circuit would detect that the battery suddenly seems to stop drawing current from its charging terminal, and could then immediately measure the voltage on the discharging terminal.)

The advantage this would offer, instead of setting up an arbitrary communications-protocol between a battery and its device, is a simpler internal chip as well.

But If somebody did that, it would still assume a fixed low-endpoint voltage, corresponding to a Sate Of Charge of 0%. This might as well be the voltage, at which Li-Ion Batteries generally start to produce Li2O , which I think is at 2.5V .

(Edit 12/13/2016 : Actually, the battery of the Samsung Galaxy S6 Phone is soldered in. Therefore, it does not need to be an info-battery, and only has 2 terminals.)

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