3

My Samsung Galaxy Tab Pro 10 (SM-T520) will discharge when connected. While the battery icon shows that it's charging, the tablet will still discharge, albeit more slowly than when not connected. This happens even under "low" use. For example, I'll have the screen brightness set to ~15% and just be browsing websites (simple forum posts trying to resolve this issue). The tablet is connected using the stock Samsung wall charger and cable that came with it, and I'll still lose a percentage point every few minutes.

Things I've tried:

  • Different chargers
  • Different cables
  • Different battery (yes, this happens with a brand new battery installed by a Samsung representative)

I took it to a certified Samsung repair point to have it checked out and they ended up changing the battery. Presumably, they run some sort of test to decide it was the battery's fault so, for the moment, I am assuming there is no other hardware problem.

I am using CyanogenMod 11 (11-20150105-NIGHTLY-picassowifi). Reading up on the problem, I found forum posts (for example, here) that suggest that some apps and/or widgets could cause this type of behavior.

Sadly, they don't mention which ones and I'd really like to avoid uninstalling everything just to try. Another suggestion was to reset to the default ROM but ditto, I see that as a last resort unless someone can confirm that that will solve the issue. This didn't used to happen when the tablet was newer (I've had it since mid-December 2014, so less than a year) and using the same ROM, which would suggest that it might indeed be the fault of some app or another.

The full list of installed apps as reported by adb shell 'pm list packages -f':

/data/app/adarshurs.android.vlcmobileremote-1.apk=adarshurs.android.vlcmobileremote
/data/app/au.com.pickup.pmm-1.apk=au.com.pickup.pmm
/data/app/bbc.mobile.news.ww-1.apk=bbc.mobile.news.ww
/data/app/berserker.android.apps.sshdroid-2.apk=berserker.android.apps.sshdroid
/data/app/ccc71.bmw-1.apk=ccc71.bmw
/data/app/ch.bitspin.timely-2.apk=ch.bitspin.timely
/data/app/com.abmantis.galaxychargingcurrent.free-1.apk=com.abmantis.galaxychargingcurrent.free
/data/app/com.accuweather.android-2.apk=com.accuweather.android
/data/app/com.ADnet-1.apk=com.ADnet
/data/app/com.adobe.flashplayer-1.apk=com.adobe.flashplayer
/data/app/com.amazon.kindle-1.apk=com.amazon.kindle
/data/app/com.anddoes.launcher-2.apk=com.anddoes.launcher
/data/app/com.anddoes.launcher.pro-1.apk=com.anddoes.launcher.pro
/data/app/com.anddoes.notifier-1.apk=com.anddoes.notifier
/data/app/com.android.vending-2.apk=com.android.vending
/data/app/com.apex.minimal-1.apk=com.apex.minimal
/data/app/com.AppDVision.Simata-1.apk=com.AppDVision.Simata
/data/app/com.appiator.defaultappmanager-1.apk=com.appiator.defaultappmanager
/data/app/com.avast.android.mobilesecurity-1.apk=com.avast.android.mobilesecurity
/data/app/com.bammsoft.scorekeeper-1.apk=com.bammsoft.scorekeeper
/data/app/com.bravolang.dictionary.greek-2.apk=com.bravolang.dictionary.greek
/data/app/com.bubblesoft.android.bubbleupnp-2.apk=com.bubblesoft.android.bubbleupnp
/data/app/com.ccpcreations.android.appdialer-1.apk=com.ccpcreations.android.appdialer
/data/app/com.chessrepertoire.garlami-1.apk=com.chessrepertoire.garlami
/data/app/com.cloudmosa.puffinFree-2.apk=com.cloudmosa.puffinFree
/data/app/com.devexpert.weather-1.apk=com.devexpert.weather
/data/app/com.dropbox.android-2.apk=com.dropbox.android
/data/app/com.elpais.elpais-1.apk=com.elpais.elpais
/data/app/com.epicdevskofasoft.colonize-1.apk=com.epicdevskofasoft.colonize
/data/app/com.estrongs.android.pop-1.apk=com.estrongs.android.pop
/data/app/com.farproc.wifi.analyzer-1.apk=com.farproc.wifi.analyzer
/data/app/com.Fraom.Gel-2.apk=com.Fraom.Gel
/data/app/com.gekkosteam.holotorch-1.apk=com.gekkosteam.holotorch
/data/app/com.gombosdev.ampere-1.apk=com.gombosdev.ampere
/data/app/com.google.android.apps.books-1.apk=com.google.android.apps.books
/data/app/com.google.android.apps.docs.editors.docs-1.apk=com.google.android.apps.docs.editors.docs
/data/app/com.google.android.apps.genie.geniewidget-1.apk=com.google.android.apps.genie.geniewidget
/data/app/com.google.android.apps.magazines-1.apk=com.google.android.apps.magazines
/data/app/com.google.android.apps.maps-1.apk=com.google.android.apps.maps
/data/app/com.google.android.apps.plus-1.apk=com.google.android.apps.plus
/data/app/com.google.android.calendar-2.apk=com.google.android.calendar
/data/app/com.google.android.gm-1.apk=com.google.android.gm
/data/app/com.google.android.gms-1.apk=com.google.android.gms
/data/app/com.google.android.googlequicksearchbox-2.apk=com.google.android.googlequicksearchbox
/data/app/com.google.android.marvin.talkback-1.apk=com.google.android.marvin.talkback
/data/app/com.google.android.music-1.apk=com.google.android.music
/data/app/com.google.android.play.games-1.apk=com.google.android.play.games
/data/app/com.google.android.talk-2.apk=com.google.android.talk
/data/app/com.google.android.tts-2.apk=com.google.android.tts
/data/app/com.google.android.videos-1.apk=com.google.android.videos
/data/app/com.google.android.youtube-1.apk=com.google.android.youtube
/data/app/com.google.earth-2.apk=com.google.earth
/data/app/com.grooky.reader-1.apk=com.grooky.reader
/data/app/com.guardian-1.apk=com.guardian
/data/app/com.handmark.expressweather-2.apk=com.handmark.expressweather
/data/app/com.hobbyistsoftware.android.vlcremote_usfree-1.apk=com.hobbyistsoftware.android.vlcremote_usfree
/data/app/com.hungrybolo.remotemouseandroid-2.apk=com.hungrybolo.remotemouseandroid
/data/app/com.imdb.mobile-2.apk=com.imdb.mobile
/data/app/com.josegd.monthcalwidget-2.apk=com.josegd.monthcalwidget
/data/app/com.jrtstudio.AnotherMusicPlayer-2.apk=com.jrtstudio.AnotherMusicPlayer
/data/app/com.keramidas.TitaniumBackup-1.apk=com.keramidas.TitaniumBackup
/data/app/com.kineticgamestudios.airtunes.android-2.apk=com.kineticgamestudios.airtunes.android
/data/app/com.levelup.touiteur-2.apk=com.levelup.touiteur
/data/app/com.mediocre.smashhit-2.apk=com.mediocre.smashhit
/data/app/com.merriamwebster-2.apk=com.merriamwebster
/data/app/com.MeteoGr-1.apk=com.MeteoGr
/data/app/com.microsoft.office.word-1.apk=com.microsoft.office.word
/data/app/com.mobilityflow.tvp-1.apk=com.mobilityflow.tvp
/data/app/com.mobisystems.msdict.embedded.wireless.oxford.dictionaryofenglish-1.apk=com.mobisystems.msdict.embedded.wireless.oxford.dictionaryofenglish
/data/app/com.mxtech.videoplayer.ad-1.apk=com.mxtech.videoplayer.ad
/data/app/com.n7mobile.nplayer-2.apk=com.n7mobile.nplayer
/data/app/com.nerdyoctopus.gamedots-2.apk=com.nerdyoctopus.gamedots
/data/app/com.nexonm.dominations.adk-1.apk=com.nexonm.dominations.adk
/data/app/com.oasisfeng.greenify-2.apk=com.oasisfeng.greenify
/data/app/com.o_taiji.digitimer7-1.apk=com.o_taiji.digitimer7
/data/app/com.oup.gab.odquicksearch-1.apk=com.oup.gab.odquicksearch
/data/app/com.overlook.android.fing-1.apk=com.overlook.android.fing
/data/app/com.quizdom-2.apk=com.quizdom
/data/app/com.ray.puntada.icons.free-1.apk=com.ray.puntada.icons.free
/data/app/com.ray.shadow.free-2.apk=com.ray.shadow.free
/data/app/com.rdr.widgets.core-1.apk=com.rdr.widgets.core
/data/app/com.roymam.android.notificationswidget-2.apk=com.roymam.android.notificationswidget
/data/app/com.sedevelop.dict.esgreekfl.free-1.apk=com.sedevelop.dict.esgreekfl.free
/data/app/com.SimpleMoonPhaseWidget-1.apk=com.SimpleMoonPhaseWidget
/data/app/com.skype.raider-2.apk=com.skype.raider
/data/app/com.socialnmobile.dictapps.notepad.color.note-2.apk=com.socialnmobile.dictapps.notepad.color.note
/data/app/com.softwarebakery.drivedroid-1.apk=com.softwarebakery.drivedroid
/data/app/com.sonelli.juicessh-1.apk=com.sonelli.juicessh
/data/app/com.spotify.music-1.apk=com.spotify.music
/data/app/com.stackexchange.marvin-2.apk=com.stackexchange.marvin
/data/app/com.supercell.clashofclans-2.apk=com.supercell.clashofclans
/data/app/com.symbolic.pitchlab-2.apk=com.symbolic.pitchlab
/data/app/com.teslacoilsw.launcher-2.apk=com.teslacoilsw.launcher
/data/app/com.thecvsi.endgame-1.apk=com.thecvsi.endgame
/data/app/com.thecvsi.tactictrainer-1.apk=com.thecvsi.tactictrainer
/data/app/com.tommedley.chatsey-1.apk=com.tommedley.chatsey
/data/app/com.touchfoo.swordigo-1.apk=com.touchfoo.swordigo
/data/app/com.touchtype.swiftkey-1.apk=com.touchtype.swiftkey
/data/app/com.uc.browser.hd-1.apk=com.uc.browser.hd
/data/app/com.utorrent.client-2.apk=com.utorrent.client
/data/app/com.viber.voip-1.apk=com.viber.voip
/data/app/com.wentam.divider-2.apk=com.wentam.divider
/data/app/com.wisteria.stone.dog-2.apk=com.wisteria.stone.dog
/data/app/com.yahoo.mobile.client.android.weather-2.apk=com.yahoo.mobile.client.android.weather
/data/app/de.hinterhofapps.sliderwidget-1.apk=de.hinterhofapps.sliderwidget
/data/app/de.kroegerama.android4batpercent-1.apk=de.kroegerama.android4batpercent
/data/app/de.robv.android.xposed.installer-1.apk=de.robv.android.xposed.installer
/data/app/es.grupoplaneta.diccionario.RAE-1.apk=es.grupoplaneta.diccionario.RAE
/data/app/flipboard.app-1.apk=flipboard.app
/data/app/ginlemon.flowerpro-2.apk=ginlemon.flowerpro
/data/app/gr.androiddev.taxibeat-2.apk=gr.androiddev.taxibeat
/data/app/gr.cosmical.android.AthensBook-2.apk=gr.cosmical.android.AthensBook
/data/app/gr.digitalblast.drivesafe-2.apk=gr.digitalblast.drivesafe
/data/app/gr.exodus.naftemporiki-1.apk=gr.exodus.naftemporiki
/data/app/jackpal.androidterm-1.apk=jackpal.androidterm
/data/app/jwtc.android.chess-1.apk=jwtc.android.chess
/data/app/net.intrinsicdroid.wikitab-1.apk=net.intrinsicdroid.wikitab
/data/app/net.nurik.roman.dashclock-2.apk=net.nurik.roman.dashclock
/data/app/org.cwf.tvxs-1.apk=org.cwf.tvxs
/data/app/org.ips.ests.chessopener-1.apk=org.ips.ests.chessopener
/data/app/org.pocketworkstation.pckeyboard-1.apk=org.pocketworkstation.pckeyboard
/data/app/org.telegram.messenger-2.apk=org.telegram.messenger
/data/app/org.videolan.vlc.betav7neon-1.apk=org.videolan.vlc.betav7neon
/data/app/org.wikipedia-1.apk=org.wikipedia
/data/app/org.wikipedia.beta-1.apk=org.wikipedia.beta
/data/app/org.wiktionary-1.apk=org.wiktionary
/data/app/org.zooper.zwfree-2.apk=org.zooper.zwfree
/data/app/org.zwanoo.android.speedtest-2.apk=org.zwanoo.android.speedtest
/data/app/pl.org.zielinscy.freeciv-1.apk=pl.org.zielinscy.freeciv
/data/app/se.maginteractive.rumble-2.apk=se.maginteractive.rumble
/data/app/stericson.busybox-1.apk=stericson.busybox
/data/app/tv.airwire-1.apk=tv.airwire
/data/app/uk.co.aifactory.backgammonfree-2.apk=uk.co.aifactory.backgammonfree
/data/app/uk.co.aifactory.chessfree-2.apk=uk.co.aifactory.chessfree
/system/app/Apollo.apk=com.andrew.apollo
/system/app/BasicDreams.apk=com.android.dreams.basic
/system/app/Bluetooth.apk=com.android.bluetooth
/system/app/BluetoothExt.apk=org.codeaurora.bluetooth
/system/app/Browser.apk=com.android.browser
/system/app/Calculator.apk=com.android.calculator2
/system/app/Calendar.apk=com.android.calendar
/system/app/Camera2.apk=com.android.camera2
/system/app/CertInstaller.apk=com.android.certinstaller
/system/app/CMBugReport.apk=org.cyanogenmod.bugreport
/system/app/CMFileManager.apk=com.cyanogenmod.filemanager
/system/app/CMHome.apk=org.cyanogenmod.launcher.home
/system/app/CMWallpapers.apk=com.cyanogenmod.wallpapers
/system/app/DeskClock.apk=com.android.deskclock
/system/app/Development.apk=com.android.development
/system/app/DocumentsUI.apk=com.android.documentsui
/system/app/DownloadProviderUi.apk=com.android.providers.downloads.ui
/system/app/DSPManager.apk=com.bel.android.dspmanager
/system/app/Email.apk=com.android.email
/system/app/Exchange2.apk=com.android.exchange
/system/app/FaceLock.apk=com.android.facelock
/system/app/Galaxy4.apk=com.android.galaxy4
/system/app/Gallery2.apk=com.android.gallery3d
/system/app/GoogleCalendarSyncAdapter.apk=com.google.android.syncadapters.calendar
/system/app/GoogleContactsSyncAdapter.apk=com.google.android.syncadapters.contacts
/system/app/GoogleEars.apk=com.google.android.ears
/system/app/HoloSpiralWallpaper.apk=com.android.wallpaper.holospiral
/system/app/HTMLViewer.apk=com.android.htmlviewer
/system/app/KeyChain.apk=com.android.keychain
/system/app/LatinIME.apk=com.android.inputmethod.latin
/system/app/LiveWallpapers.apk=com.android.wallpaper
/system/app/LiveWallpapersPicker.apk=com.android.wallpaper.livepicker
/system/app/LockClock.apk=com.cyanogenmod.lockclock
/system/app/MagicSmokeWallpapers.apk=com.android.magicsmoke
/system/app/MediaUploader.apk=com.google.android.apps.uploader
/system/app/NoiseField.apk=com.android.noisefield
/system/app/PackageInstaller.apk=com.android.packageinstaller
/system/app/PacProcessor.apk=com.android.pacprocessor
/system/app/PhaseBeam.apk=com.android.phasebeam
/system/app/PhotoPhase.apk=org.cyanogenmod.wallpapers.photophase
/system/app/PhotoTable.apk=com.android.dreams.phototable
/system/app/PicoTts.apk=com.svox.pico
/system/app/PrintSpooler.apk=com.android.printspooler
/system/app/SoundRecorder.apk=com.android.soundrecorder
/system/app/Street.apk=com.google.android.street
/system/app/TelephonyProvider.apk=com.android.providers.telephony
/system/app/Torch.apk=net.cactii.flash2
/system/app/UserDictionaryProvider.apk=com.android.providers.userdictionary
/system/app/VideoEditor.apk=com.android.videoeditor
/system/app/VisualizationWallpapers.apk=com.android.musicvis
/system/app/VoicePlus.apk=org.cyanogenmod.voiceplus
/system/app/WAPPushManager.apk=com.android.smspush
/system/framework/framework-res.apk=android
/system/priv-app/AARSCService.apk=eu.airaudio.aarscservice
/system/priv-app/BackupRestoreConfirmation.apk=com.android.backupconfirm
/system/priv-app/CalendarProvider.apk=com.android.providers.calendar
/system/priv-app/CMAccount.apk=com.cyanogenmod.account
/system/priv-app/CMUpdater.apk=com.cyanogenmod.updater
/system/priv-app/ConfigUpdater.apk=com.google.android.configupdater
/system/priv-app/Contacts.apk=com.android.contacts
/system/priv-app/ContactsProvider.apk=com.android.providers.contacts
/system/priv-app/DefaultContainerService.apk=com.android.defcontainer
/system/priv-app/DownloadProvider.apk=com.android.providers.downloads
/system/priv-app/ExternalStorageProvider.apk=com.android.externalstorage
/system/priv-app/FusedLocation.apk=com.android.location.fused
/system/priv-app/GoogleBackupTransport.apk=com.google.android.backuptransport
/system/priv-app/GoogleFeedback.apk=com.google.android.feedback
/system/priv-app/GoogleLoginService.apk=com.google.android.gsf.login
/system/priv-app/GoogleOneTimeInitializer.apk=com.google.android.onetimeinitializer
/system/priv-app/GooglePartnerSetup.apk=com.google.android.partnersetup
/system/priv-app/GoogleServicesFramework.apk=com.google.android.gsf
/system/priv-app/InputDevices.apk=com.android.inputdevices
/system/priv-app/Keyguard.apk=com.android.keyguard
/system/priv-app/MediaProvider.apk=com.android.providers.media
/system/priv-app/OneTimeInitializer.apk=com.android.onetimeinitializer
/system/priv-app/ProxyHandler.apk=com.android.proxyhandler
/system/priv-app/RSCService.apk=com.kineticgamestudios.airtunes.android.rsc
/system/priv-app/Settings.apk=com.android.settings
/system/priv-app/SettingsProvider.apk=com.android.providers.settings
/system/priv-app/SetupWizard.apk=com.google.android.setupwizard
/system/priv-app/SharedStorageBackup.apk=com.android.sharedstoragebackup
/system/priv-app/Shell.apk=com.android.shell
/system/priv-app/SystemUI.apk=com.android.systemui
/system/priv-app/TeleService.apk=com.android.phone
/system/priv-app/ThemeChooser.apk=org.cyanogenmod.theme.chooser
/system/priv-app/ThemesProvider.apk=org.cyanogenmod.themes.provider
/system/priv-app/Trebuchet.apk=com.cyanogenmod.trebuchet
/system/priv-app/VpnDialogs.apk=com.android.vpndialogs
/system/priv-app/WallpaperCropper.apk=com.android.wallpapercropper

So, any suggestions?

  • Is this particular version of CyanogenMod known to have such problems?
  • Is it worth upgrading to 12 or a more recent version of 11?
  • Are any apps known to cause such issues?
  • Is there anything else I've missed that I could try?
  • This is typical for using a device while on a weak charger. What is the amperage of the chargers you've tried? – Matthew Read Nov 12 '15 at 19:00
  • 1
    @MatthewRead one of them is the original Samsung charger (TA10EWE): 5.3V, 2.0A. I tried measuring its strength with Ampere, but it reports wildly fluctuating values. At the moment, they range from 0 mA to ~1 A and usually hover around 7-800 mA. I have no idea how reliable those values are. I'll update the question tomorrow with the details of the other two chargers. – terdon Nov 12 '15 at 23:09
  • Ampere IMO reports what kernel reports to the system. I wrote an answer about that for How can profile (log the charging and discharging current for some time period) my battery? (see other answer there too). As for pin-pointing the apps, you may have some success using BetterBatteryStats (you'll have to configure it to record stats when plugged in as well). Also, if you've the time and will, adb shell dumpsys batterystats may help you out. – Firelord Nov 13 '15 at 11:46
  • @MatthewRead it turns out that the strength of the charger is irrelevant, the tablet needs its charger and another with the same capabilities won't cut it. – terdon Nov 14 '15 at 13:13
  • @Firelord thanks, I found that Battery Monitor Widget gave the best results. Sadly, appears that the tablet will only charge on its own charger & cable. See my answer. – terdon Nov 14 '15 at 13:14
3

t turns out I have (had) two separate issues:

  1. I had a bum battery. No combination of cable/charger would charge it correctly. I had the battery replaced and noticed that it was still not charging correctly and so posted the question. I should have done more research.

  2. Samsung devices (mine at least) seem to detect when they're being charged by a non-Samsung charger and won't pull as much charge as they can.

The main issue here was 2 since 1 was solved by the new battery. I haven't found an official source for this but the following are very suggestive:

  • This YouTube video shows a Galaxy Tab Pro 10 tablet refusing to charge at full rate when using anything but its own charger (including chargers that can provide enough amperage). The video demonstrates this by using a hardware amperometer.

  • This Android.SE answer states that:

    I believe some Samsungs look for a certain voltage on one or two of the pins of the connector, and will not work with other chargers, but I'm only guessing. What I have found with, for example, my Galaxy Tab 3, is that there are some chargers that will not register no matter what cable I use (including "charge-only" cables like from Mediabridge), and other chargers that will not charge it at the full rate unless I use a charge-only cable.

  • This XDA Developers forum post gives a HowTo for converting a normal charger to something Samsung devices can charge from. It involves soldering two pins together on the charger's board and explains that:

    The theory behind it is with samsung galaxy phones and "official chargers": if the middle 2 data pins on the usb, while getting 5v to the outer 2 pins it tells the phone that it is an official samsung charger and enables full speed charging.

    without the middle 2 pins connected (with or without data flow) will not charge at full speed. even if you supply 800mA it will only charge around 350mA

  • This CNET Forums post states:

    It does NOT mean this is what Samsung did but remember that the USB STANDARD only allows 0.5 Amperes on the STANDARD charger. To do more he had to adhere to some USB handshake that is custom, proprietary and more to tell the device there is more than 0.5 Amperes available and to draw more than allowed.

Finally, my own tests with Battery Monitor Widget and similar apps have confirmed that only the stock charger with the stock cable will charge correctly. Correctly here means that when connected, the applet reports "Charging". Anything else (including the stock charger with a different cable, one that is quite capable of charging an iPad) will report varying degrees and speeds of "Discharging".

In conclusion, it seems like this particular device will only charge correctly using the stock charger and its cable. No other chargers will work, irrespective of the output the charger is capable of providing. The tablet itself will not pull the full charge if it detects it's not being charged with the stock charger.

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