[Samsung Galaxy S 5 Unified Development] curiousrom:
S5 Battery Charging - Fake 100%

Battery & power usage in Android & in this unofficial LineageOS 16.0 is a complicated subject & everything is relative.

To add to the mix many of us have older batteries with reduced capacity & there are lots of fake ones out there. One way to check is to weigh the battery. The original Samsung for S5 weighs 45~45.2G while the fake ones found in my local shops weighs about 40G. I asked the weight to 8 local online sellers & all of them had fake ones @ 40~40.2G.

See Fake vs OEM S5 Samsung Battery for screenshots of the NFC antennae that fake OEM & many third-party batteries do not have.

I have the original OEM Samsung battery dated 2015-08, same as my S5 manufacturing date.

I collected some data & will make a post about it soon but in a nutshell when charging the S5 either in System or with the phone turned off it does not really charge the battery @ 100% with a max voltage below 4.3V.

With the OEM Samsung Travel Adapter charger w/ nominal output of 5.3V @ 2.0A & a good short USB cable I use an in-line USB multimeter to monitor the current drawn by the S5 while charging (screenshot).

Starting with the battery between 0~5% it reaches 100% on the Status bar in about 1h 10 minutes and it takes an additional 45~60 minutes before the current goes down to 0 Ampere on the multimeter and that's with the battery not really charged @ 100%.

View attachment 4684894

Charging the S5 in System to 100% + 45 minutes, disconnecting the phone then rebooting in System shows 90~92% on my S5 G900M running haggertk's 16.0 build 2019-01-09 which is the same as his previous builds.

So try that & if your battery shows 85% then it's old or a fake.

Charging the S5 turned off + 45 minutes after the charging animation stops, disconnecting because it will not boot to System otherwise* as you described I also get 90~92%.

Edit: *This was fixed in build 2019-08-15 or newer. You can now boot to System with a long press of the Power button with the S5 still connected.

I don't think it's a bug, it's Samsung that lowered the max battery voltage of the S5 when charging in an update & S5 LineageOS dev [MENTION=2693412]haggertk[/MENTION] ported it.

My guess: that's because Samsung freaked out after the Galaxy Note 7 battery fires disaster.

On the plus side not charging to the max extends the battery life expectancy.

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As seen in the second attachment graph from this site, li-ion batteries discharge faster from 100% to ~90% and also below 20%. That why you should discharge the battery to 90% or lower to check the battery usage @ idle with the screen off in Gsam Battery Monitor or BetterBatteryStats for example.

View attachment 4763707

Edit 2019-08-14: In GSam > Charts you can see the charging rate going down and the battery % curve as the battery nears 100%. It's more obvious in landscape mode & you can pinch to zoom in the charging session like in this screenshot:

View attachment 4806051

BTW the charging notification LED does not work w/ the phone turned off as of 2019-08-15. The LED does work w/ the S5 turned on.

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Charging in TWRP to 100% + 30 minutes I get a higher battery voltage (4.385~4.388V) & booting to System shows 100%.

And immediately rebooting in System again still shows 99~100%. :)

In TWRP adb is enabled by default. With the S5 connected to a computer to get the battery voltage enter this command in adb:

adb shell cat /sys/class/power_supply/battery/voltage_now

Note that the output is in microvolt so for example: 4387000 microvolt = 4.387V.

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In System rebooting when the battery shows 90% or lower will show only a normal 1-2% drop.

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"...Then turn on and wait for bootlogo then reconnect the charger" - I would not do that as it could mess-up the booting process. Better to connect after it's fully booted IMO.

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