New Nextbook Models for 2014 (Quad Core RK3188)

[B-Man]

There is tons of battery calibration apps in the Play Store, but they all require Root.

I didn't know that. I've never had battery management issues on any of my android devices before. Thanks for the info. I'll try one out.

[AMMO]

Battery Issue

I'm also having the battery issue on mine as well. As soon as it hits 30% it shuts down. I'm assuming there is no warning as it is set probably to warn you at 15%, of course it never hits that.

I think I has to do with the software incorrectly recognizing the battery charge. The way a li-on works, although it states 3.7 volts on the battery, a full charge (100%) is actually 4.2 volts, which is when the protection circuit kicks in and stops charging (i.e. green light on most devices). When it drops down to around 3.2 volts (again, most devices) it starts to warn you of low charge, because around 3.0 volts the protection circuit in the battery will consider this 0% charged and shut down the battery for safety even though it still has juice. This is because any li-on that reaches 2.5 volts is running the risk of permanent damage. I have a feeling this is incorrectly calibrated in the Nextbook software from the factory, so that when it thinks it has a 30% charge left, the charge is actually hitting the low voltage warning on the battery and the circuit is tripping, killing the device without warning.

I hope I got that across the way I mean too, I’m tired, lol.

Is there any way for you to look in the devices’ code Shaun to see if it is correctly measuring the battery level?

[shaunmt]

I'm also having the battery issue on mine as well. As soon as it hits 30% it shuts down. I'm assuming there is no warning as it is set probably to warn you at 15%, of course it never hits that.

I think I has to do with the software incorrectly recognizing the battery charge. The way a li-on works, although it states 3.7 volts on the battery, a full charge (100%) is actually 4.2 volts, which is when the protection circuit kicks in and stops charging (i.e. green light on most devices). When it drops down to around 3.2 volts (again, most devices) it starts to warn you of low charge, because around 3.0 volts the protection circuit in the battery will consider this 0% charged and shut down the battery for safety even though it still has juice. This is because any li-on that reaches 2.5 volts is running the risk of permanent damage. I have a feeling this is incorrectly calibrated in the Nextbook software from the factory, so that when it thinks it has a 30% charge left, the charge is actually hitting the low voltage warning on the battery and the circuit is tripping, killing the device without warning.

I hope I got that across the way I mean too, I’m tired, lol.

I suspect you might be correct... hopefully with root access, a third party battery management app might be able to recalibrate it correctly... but I don't have much experience using any such apps...

Is there any way for you to look in the devices’ code Shaun to see if it is correctly measuring the battery level?

This would be located in the source code, which I don't have...

ShaunMT

[jrubin]

Yes, it's still going well. I had to request a bit of assistance from some of the other devs here, I've made a lot of progress in the past few days.

I'm currently working on TWRP recovery. I need to verify that TWRP is working so I can decide what format to package the ROM and patches in.

At present, due to the structure of Rockchip ROMs, it looks like some things (like parameter files for storage layout) are only going to be flashable via PC or stock recovery, while other things will be flashable using TWRP.

In the future I hope to be able to modify TWRP or create a script or program so that we can flash any part of the ROM from tablet without reverting back to stock recovery.

I should definitely get a rooted KK rom package out this weekend and possibly more.

ShaunMT

So...... Hows progress going?

[shaunmt]

So...... Hows progress going?

Unfortunately, I haven't had time to do anything in the past week... but, I'm on vacay again for the rest of this week.

You should see my ROM in the next 24 hours and maybe some more stuff sometime this week too.

ShaunMT

[AMMO]

Thanks again for your hard work and dedication to this. I'll definitely be testing this for you. My hopes are to get a much better storage partition.
~Jeff

Sent from my SAMSUNG-SM-G900A using Tapatalk

[B-Man]

There is tons of battery calibration apps in the Play Store, but they all require Root.

I've tried several of these battery calibration apps on my rooted 4.2.2, and none of them help. At some point I hope this issue can be solved with a ROM, it's frustrating when you're in the middle of typing an email and just shuts off. It powers off somewhere between 25% and 35%, hard to tell if you aren't staring at the % when it powers off.

[orlandoamg360]

I've tried several of these battery calibration apps on my rooted 4.2.2, and none of them help. At some point I hope this issue can be solved with a ROM, it's frustrating when you're in the middle of typing an email and just shuts off. It powers off somewhere between 25% and 35%, hard to tell if you aren't staring at the % when it powers off.

Same issue here. And if your tablet is like mine, the problem is only going to get worse. It would shut off between 25% and 35% but lately I've found that it shuts down somewhere between 45% and 60%! Ridiculous! And since I'm always in the middle of doing something, I'm guessing the cache partition gets corrupted because upon boot up, it always freezes at the nextbook powered by android screen. I have to manually get into recovery and wipe the cache partition whick makes it boot up again.

[shaunmt]

Battery issues...

I'm currently working to finish up my first ROM for the NX785QC8G and I've noticed that mine also has the same battery issue... shuts off somewhere between 30% and 40%... then acts like it is dead and won't even turn on while plugged in until after it has charged for awhile...

I suspect the battery monitoring just isn't calibrated properly... will let everyone know if I find any solutions...

ShaunMT

[shaunmt]

I'm currently working to finish up my first ROM for the NX785QC8G and I've noticed that mine also has the same battery issue... shuts off somewhere between 30% and 40%... then acts like it is dead and won't even turn on while plugged in until after it has charged for awhile...

I suspect the battery monitoring just isn't calibrated properly... will let everyone know if I find any solutions...

ShaunMT

Well... when I finally got my tablet to boot up again, the battery level was reported as 11% and climbing.

I believe these batteries are supposed to be shutdown with 10% charge remaining, because they don't like to take a charge after being drained completely.

So... either I wasn't paying close enough attention to the battery level while waiting for it to die today (possible), or the system has automatically recalibrated the battery monitoring and indicator (hopeful & it should self calibrate), or there is something else wrong that causes innacurate battery monitoring (who knows...).

I'll continue to report any further findings...

ShaunMT

[B-Man]

It automatically recalibrates after the forced shut down. I've noticed the same thing you're seeing. It weird and doesn't seem to make any sense. Once its charged up again tho it'll do the same thing and quit around 30%, or what the tablet THINKS is 30%. Very annoying.

[shaunmt]

It automatically recalibrates after the forced shut down. I've noticed the same thing you're seeing. It weird and doesn't seem to make any sense. Once its charged up again tho it'll do the same thing and quit around 30%, or what the tablet THINKS is 30%. Very annoying.

That would suggest that it is either a problem involving monitoring the max charge level or discharge rate... or that the cached battery stats are getting corrupted.

I bet a good battery monitoring app or calibration tool could provide some answers regarding the charge levels and discharge rates, and possibly recalibrate the battery stats.

However, if the problem lies in the chached battery stats files... that's probably related to cheap nand...

[shaunmt]

Question for people with battery issue (battery runs out at 20% to 40%)

This question is for all of you guys who reported the battery issue where the battery runs out before the battery warning appears:

Have all of you upgraded from 4.2.2 to 4.4.2?

I'm wondering if the battery needs to be recalibrated because we upgraded the ROM without wiping /data and /cache. Some of the threads I've read in my research indicate that batteries may need to be recalibrated after changing ROMs.

Otherwise, I noticed that there are a lot of discussions about the Nexus 7 having the exact same issue after the 4.2.2. update. It was determined to be a problem caused with Android, which to my knowledge has never been fixed... This is what happens:

When battery is truly fully charged (left on charger all day / overnight), the battery stays 100% for a longtime (as if it were actually "overcharged", perhaps the battery "max" calculation is wrong)... then battery indicator finally starts to decrease at a what appears to be a normal steady rate, but the battery completely runs out before the indicator does... and the problem gets worse on subsequent charges...

The best fix for the Nexus 7 (which may only be temporary?) seems to be charging the device to 100%, then turning it off and unplugging it and waiting a while (maybe an hour or so?) then turn it on and check the battery... you should find that the battery percentage has fallen... charge it up to 100% again and repeat... after a few times you should have your device fully charged again and calibrated correctly... additionally, at this point it may or may not be helpful to also use a battery calibration app to "calibrate" the battery monitoring and / or delete the batterystats file (or do a wipe cache or factory reset for the same result).

I've reflashed mine with my new ROM a couple of times tonight... I'll try wiping everything after my last flash and report if the battery problem still exists... if it does, I plan to try the suggested Nexus fix next...

ShaunMT

[B-Man]

I'm having the battery issue on 4.2.2 rooted

[Perfectpitch]

Having the issue on rooted 4.4.2