PRS-T1 Battery problem, shuts down at 70%

MichF · 05-09-2012, 05:30 AM

TL;DR:
PRS-T1 shuts down at 70% charge. What to do?

Hi there!

I have this problem with my PRS-T1:
Discharging seems ok at first, slowly going down from 100%
after fully charged. But shortly after it hits 70% (after maybe
2 days of heavy use) the device suddenly decides that the battery
is empty and shuts down. I even cannot turn it on again, unless
I connect the charger. When I check the battery state immediately
after this, it tells me that it's still at 70%.

My PRS-T1 is fairly new. This problem is present when the
device is rooted as well as when the original firmware is restored
(to the latest firmware version). WIFI is switched off.
I also wiped batterystats.bin, without any effect.
I am using a wall charger.

Any idea what I could try to regain the full battery capacity?
Or which mechanism android uses to sense 'battery empty'
besides the charge percentage?
Is it possible to buy a replacement battery somewhere on the net?

Thanks!
MichF

frekilson · 05-14-2012, 09:26 AM

I have the exact same problem - I dropped my reader on the tiles from 3-4ft (cracking the plastic) and since then it shuts down @70% battery. No other apparent damage, only the too short battery life...

uboot · 05-14-2012, 11:56 AM

did you guys notice the wiki or try the search function?

carpetmojo · 05-15-2012, 03:38 AM

Quote:

Originally Posted by uboot

did you guys notice the wiki or try the search function?

Further explanation please ?

uboot · 05-15-2012, 05:03 AM

Go to the link in my signature and search for battery.

Or go to https://www.mobileread.com/forums/search.php and enter "battery prst1" into the search field (without quotation marks), then press "search"

MichF · 05-15-2012, 01:34 PM

uboot, with all due respect, did you read my posting? I read every thread regarding prs t1 battery on mobileread and even on the-ebook.org, and read the complete wiki tweaks page. So far none of the suggested fixes helped.

luvduchovny · 05-15-2012, 02:55 PM

Maybe there is a loose connection to the battery. You might have to get Sony involved.

uboot · 05-16-2012, 06:31 AM

Ok, my fault, I'm sorry for offending you

Well - there is an emergency shutdown - well, not a real shutdown, more like instant power off - as soon as the battery voltage drops below a sanity treshold.

Normally, the OS monitors battery voltage drop over time and tries to estimate remaining capacity. Depending on the condition of the battery, this drop is more or less steady and smooth.

100% corresponds to a maximum voltage a healthy li-battery has when fully charge.

If it shows 70% right after charge, I suspect your battery has died. Either by a total discharge or because it was faulty from the beginning.

But you can try to "revive" it by repeatedly charging / disconnecting to squeeze more juice into it...

In the wiki there is a link to a battery calibration tool which shows the voltage.

Could you please tell us the voltage of your battery when fully charged and charger disconnected?

Does it drop rapidly then disconnected?

frekilson · 05-16-2012, 08:46 AM

No no uboot, my case is that after the accident the battery IS charged to 100%, then over the course of a couple of days (1-2 hours of use every day - reading & browsing) it gradually drops by 5-10% each day and then at ~70% it suddenly discharges rapidly - I usually find it dead (& unwilling to start) in the morning, with only 5% battery left. It also charges very quikly - 30 minutes max and the light goes out.
I rooted it two months ago and did the battery.bin deletion trick a month ago - it had 10-12 days of battery life until the accident. I did the battery.bin deletion again yesterday (in case the fall did some software malfunction). I will check the voltage and post what it is @ different battery levels.

uboot · 05-16-2012, 12:14 PM

Hm... I had my battery drained over night several times, but this was due to apps and it always ran down to 10% - didn't stop at 70%....

The voltage at 70% and lower will be the clue.

Also - have you read about the issues with underpowered chargers? The charger should provide at least 5V/750mA to make T1 charge properly. More mA is better and won't damage anything. I have a universal 5V/2000mA USB charger. Charging with computer / USB is not sufficient to gain full capacity.

Toxaris · 05-18-2012, 08:28 AM

This may sound strange, but do you carry it outside and what is the surrounding temperature? It might be cold...

However, I think it is a loose contact.

uboot · 05-18-2012, 12:17 PM

wouldn't a loose contact occasionally cause instant power failure, independently from battery gauge?

frekilson · 05-30-2012, 01:34 AM

Ok, so after the second recalibration of the battery (on May the 15th) now it is draining much slower. I charged it 15 days ago and now it's @30% (1-2 hrs of use every day + some wifi). I guess the drop on the tiles did something to corrupt its memory because FBReader fails to start, and the Google services & market began throwing errors so I had to deinstall them because it was getting annoying. I guess I'll have to reinstall the root package to fix all software issues...

Hartsock · 05-30-2012, 09:13 AM

I see that happening with my battery on an unrooted T1. Full charge, put it in standby. A day or two later the T1 has turned itself off and battery shows 0. I think it is a power monitoring problem but does that include the possibility that the battery circuitry is defective?

GeckoFriend · 06-18-2012, 08:47 AM

My unrooted T-1 has now developed this problem. After five months of normal battery life it's now shutting down after only 1-2 days of use. I have read all threads I can find about batteries. I read the wiki article about battery gauge recalibration but I do not understand how to apply that information to an unrooted device.

05-09-2012, 05:30 AM	#1
MichF Junior Member Posts: 3 Karma: 10 Join Date: May 2012 Device: PRS-T1	Battery problem, shuts down at 70% TL;DR: PRS-T1 shuts down at 70% charge. What to do? Hi there! I have this problem with my PRS-T1: Discharging seems ok at first, slowly going down from 100% after fully charged. But shortly after it hits 70% (after maybe 2 days of heavy use) the device suddenly decides that the battery is empty and shuts down. I even cannot turn it on again, unless I connect the charger. When I check the battery state immediately after this, it tells me that it's still at 70%. My PRS-T1 is fairly new. This problem is present when the device is rooted as well as when the original firmware is restored (to the latest firmware version). WIFI is switched off. I also wiped batterystats.bin, without any effect. I am using a wall charger. Any idea what I could try to regain the full battery capacity? Or which mechanism android uses to sense 'battery empty' besides the charge percentage? Is it possible to buy a replacement battery somewhere on the net? Thanks! MichF

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05-14-2012, 09:26 AM	#2
frekilson Junior Member Posts: 4 Karma: 10 Join Date: May 2012 Device: Sony PRS T1	I have the exact same problem - I dropped my reader on the tiles from 3-4ft (cracking the plastic) and since then it shuts down @70% battery. No other apparent damage, only the too short battery life...

05-14-2012, 11:56 AM	#3
uboot Evangelist Posts: 425 Karma: 75216 Join Date: Nov 2011 Location: old europe Device: Kobo Mini, Tolino Epos 2	did you guys notice the wiki or try the search function?

05-15-2012, 05:03 AM	#5
uboot Evangelist Posts: 425 Karma: 75216 Join Date: Nov 2011 Location: old europe Device: Kobo Mini, Tolino Epos 2	Go to the link in my signature and search for battery. Or go to https://www.mobileread.com/forums/search.php and enter "battery prst1" into the search field (without quotation marks), then press "search"

05-15-2012, 01:34 PM	#6
MichF Junior Member Posts: 3 Karma: 10 Join Date: May 2012 Device: PRS-T1	uboot, with all due respect, did you read my posting? I read every thread regarding prs t1 battery on mobileread and even on the-ebook.org, and read the complete wiki tweaks page. So far none of the suggested fixes helped.

05-15-2012, 02:55 PM	#7
luvduchovny Zealot Posts: 145 Karma: 137186 Join Date: Mar 2009 Device: Sony Reader PRS-500, PRS-600, PRS-650, PRS-T1, PRS-T3	Maybe there is a loose connection to the battery. You might have to get Sony involved.

05-16-2012, 06:31 AM	#8
uboot Evangelist Posts: 425 Karma: 75216 Join Date: Nov 2011 Location: old europe Device: Kobo Mini, Tolino Epos 2	Ok, my fault, I'm sorry for offending you Well - there is an emergency shutdown - well, not a real shutdown, more like instant power off - as soon as the battery voltage drops below a sanity treshold. Normally, the OS monitors battery voltage drop over time and tries to estimate remaining capacity. Depending on the condition of the battery, this drop is more or less steady and smooth. 100% corresponds to a maximum voltage a healthy li-battery has when fully charge. If it shows 70% right after charge, I suspect your battery has died. Either by a total discharge or because it was faulty from the beginning. But you can try to "revive" it by repeatedly charging / disconnecting to squeeze more juice into it... In the wiki there is a link to a battery calibration tool which shows the voltage. Could you please tell us the voltage of your battery when fully charged and charger disconnected? Does it drop rapidly then disconnected?

05-16-2012, 08:46 AM	#9
frekilson Junior Member Posts: 4 Karma: 10 Join Date: May 2012 Device: Sony PRS T1	No no uboot, my case is that after the accident the battery IS charged to 100%, then over the course of a couple of days (1-2 hours of use every day - reading & browsing) it gradually drops by 5-10% each day and then at ~70% it suddenly discharges rapidly - I usually find it dead (& unwilling to start) in the morning, with only 5% battery left. It also charges very quikly - 30 minutes max and the light goes out. I rooted it two months ago and did the battery.bin deletion trick a month ago - it had 10-12 days of battery life until the accident. I did the battery.bin deletion again yesterday (in case the fall did some software malfunction). I will check the voltage and post what it is @ different battery levels.

05-16-2012, 12:14 PM	#10
uboot Evangelist Posts: 425 Karma: 75216 Join Date: Nov 2011 Location: old europe Device: Kobo Mini, Tolino Epos 2	Hm... I had my battery drained over night several times, but this was due to apps and it always ran down to 10% - didn't stop at 70%.... The voltage at 70% and lower will be the clue. Also - have you read about the issues with underpowered chargers? The charger should provide at least 5V/750mA to make T1 charge properly. More mA is better and won't damage anything. I have a universal 5V/2000mA USB charger. Charging with computer / USB is not sufficient to gain full capacity.

05-18-2012, 08:28 AM	#11
Toxaris Wizard Posts: 4,520 Karma: 121692313 Join Date: Oct 2009 Location: Heemskerk, NL Device: PRS-T1, Kobo Touch, Kobo Aura	This may sound strange, but do you carry it outside and what is the surrounding temperature? It might be cold... However, I think it is a loose contact.

05-18-2012, 12:17 PM	#12
uboot Evangelist Posts: 425 Karma: 75216 Join Date: Nov 2011 Location: old europe Device: Kobo Mini, Tolino Epos 2	wouldn't a loose contact occasionally cause instant power failure, independently from battery gauge?

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05-30-2012, 01:34 AM	#13
frekilson Junior Member Posts: 4 Karma: 10 Join Date: May 2012 Device: Sony PRS T1	Ok, so after the second recalibration of the battery (on May the 15th) now it is draining much slower. I charged it 15 days ago and now it's @30% (1-2 hrs of use every day + some wifi). I guess the drop on the tiles did something to corrupt its memory because FBReader fails to start, and the Google services & market began throwing errors so I had to deinstall them because it was getting annoying. I guess I'll have to reinstall the root package to fix all software issues...

05-30-2012, 09:13 AM	#14
Hartsock Enthusiast Posts: 48 Karma: 38 Join Date: Mar 2012 Device: Sony PRS-T1	I see that happening with my battery on an unrooted T1. Full charge, put it in standby. A day or two later the T1 has turned itself off and battery shows 0. I think it is a power monitoring problem but does that include the possibility that the battery circuitry is defective?

06-18-2012, 08:47 AM	#15
GeckoFriend Guru Posts: 618 Karma: 1164945 Join Date: Jan 2012 Location: SF Bay Area, California, USA Device: iPhone 7+, iPad Mini4, Kindle Voyage	My unrooted T-1 has now developed this problem. After five months of normal battery life it's now shutting down after only 1-2 days of use. I have read all threads I can find about batteries. I read the wiki article about battery gauge recalibration but I do not understand how to apply that information to an unrooted device.