Tablet Keeps Turning Off

[Zentraleinheit]

I Have an Android 4.1.1 Sensis N78 RK30-anpei7008Trsy-user-r4.1.1.4.083 tablet with kernel version 3.0.8+ and build number RK30-anpei7008Trsy-user-r4.0.83.20130106 that I got almost a year ago. Till the weather got colder the tablet worked fine, however, as of the last 2 months it has acted strange.

For after 5 minutes or so on battery power the tablet shuts down with-out warning. Any attempt at restart just results in shorting the on time before shutdown. Then to the point that tablet "dies" even before getting to what I call "the unlock page."

The sequence of events usually follow what happen last Thursday night..

1: Starting at 1% reported battery charge, I recharge the battery on AC.
2: After about 90 minutes the tablet is charged at 100%
3: When, come Friday morning, I use the tablet the reported battery charge is at 99%-100 %, but, after 5 minutes there is an abrupt shutdown.
4: After restarting the tablet the reported battery charge is 18%, then after a minute, the tablet shut down. Any more restart attempts leads nowhere.
5: After leaving the tablet off for 8 hours I restart it and informed that the recharge level is 80%, but, it still will shut down after 5 minutes
6: By Saturday morning the tablet again shown 1% battery level, but, after plugging in to my car's cigarette lighter the battery level jumps to 80%. But, after 5 minutes I back at #4.

Plus, I have also found that if the power cable wire is disbured, the tablet will turn off

Using a Battery App it reported that:
Battery Health: Good
Technology: Li-ion
Temperatrure: 32.0F
Voltage: 3.0V

I been searching on the net, but, found nothing

Even tried contacting the company, but, my mails keep coming back marked with quota exceed.

I haven't received replies form other sites I have asked

 

[leeshor]

Welcome to the forum

This is just a wild guess but I'd say there is a problem with a connection in the battery contacts or the charging circuit. The only suggestion I have is to take it apart and check all the connections.

 

[Zentraleinheit]

The only suggestion I have is to take it apart and check all the connections

OK, but, how?

I beleve that the back just snaps into (and out of) place, but, is there a trick that I shold look out for?

Plus, one I do get inside, would I notice anything out of place?

Or out comes the volt reader?

 

[leeshor]

I wish I had an answer. The best I can say is eyeball it to see if anything looks loose.

 

[Zentraleinheit]

I got the back off and to my eyes nothing look wrong.

I took a voltmeter to the battery and it read 3.7v

If the battery is ok then could something effected the tablet when it was used/stored/recharged in below freezing (20F) weather?

 

[leeshor]

Possibly. Go through several deep discharge and charge cycles to see if anything changes. If it is the charging circuit itself it may be difficult to tell.

 

[Zentraleinheit]

Well, I'll try your suggestion and see what happens. If that don't work then this tablet may be heading back home to China for recycling

However, I do have one more question.

How do you read Android's built in battery chart?

I took the screenshot below 1 minute after turning on the tablet (and after it being off for 11 hours and being on AC recharge for 3 hours before that).






Yet it shows I been on battery power for over 7 minutes 16 seconds, and what is the 24 minutes 18 seconds notation on the X axis of the graft denote?

 

[casarova]

Have you tried a different charger cable?