Yet Another Power/battery Issue

[DennisOS2]

I have found on my 12.2 that there is a discrepancy in the battery readings between just before it dies and five minutes after you plug in the charger after it dies. Mine will count down till1% then die. Then after 5min on the charger bringing up the battery charge indicator will show 18 - 23% charged. The remaining ~80% will take 10 - 12hrs to finish. Is this plausible? Expected? I thought these types of batteries didn't develop memories.

 

[B. Diddy]

That doesn't sound too unusual. When the battery gets low, the accuracy of the battery meter worsens anyway, so 1% or 5% isn't necessarily an exact measurement. On top of that, the battery charging curve will usually be pretty steep at first, then flatten out as you get closer to 100%. This is a good read: Charging Lithium-Ion Batteries – Battery University

As an aside, I would strongly recommend against regularly discharging your battery that low. Deep discharges decrease your battery's overall lifespan, which is important for devices that have nonremovable batteries.

 

[DennisOS2]

Thanks for the reply. all good info. You may have identified another issue that I have caused. I have often waited till its dead before connecting the charger. What are the symptoms of a battery going south?

 

[Beut]

Mine will count down till1% then die. Then after 5min on the charger bringing up the battery charge indicator will show 18 - 23% charged. The remaining ~80% will take 10 - 12hrs to finish. Is this plausible? Expected? I thought these types of batteries didn't develop memories.

This is not an opinion or guessing as I have been fixed dozen of tablets with similar problem like yours. Battery capacity fluctuation and long charge is an obvious sign of cracked battery connector. I see very often the battery goes up 20 to 40% , depending on the cracks, after resoldering the battery connector. Your problem is very common in many Samsung tablets but I see many users still try to fix something else not related to this connector.
New battery will have the same problem if battery connector doesn't get fixed.
This is an example how the circuit can get fool to read the battery, disconnect your battery then plugin your USB charging cable, press the HOME button, within 10 seconds, you will see the green battery icon show up 100% fully charged, then it will disappear. The charging circuit doesn't see any current coming and it thinks the battery is fully charged. Try it and you will see why the circuit can't read the battery capacity correctly if the connector is cracked.

Here is example of people taking the advice seriously and fixed the problem, threat 17 and 18
http://forum.xda-developers.com/galaxy-note-10-2014/help/battery-fast-drain-t3143951/page2

 

[B. Diddy]

Thanks for the reply. all good info. You may have identified another issue that I have caused. I have often waited till its dead before connecting the charger. What are the symptoms of a battery going south?

The main symptoms would be faster discharge rates, and perhaps increased heat while charging. But Beut makes some good points as well about the battery connector.

 

[larry1014]

I gave up on galaxy 12.2. It won't even turn on now. The flickering, battery gauge going up and down. I just bought a new 9.7 tab S2 and happy so far ( 2 days)

 

[DennisOS2]

I gave up on galaxy 12.2. It won't even turn on now. The flickering, battery gauge going up and down. I just bought a new 9.7 tab S2 and happy so far ( 2 days)

Keep us posted please.

Dennis