PRS-T1 Common Recharge Problem Fixed, might help

[StamosD]

My Sony PRS-T1 went into the Empty > Charge > Short Battery Life then the Empty > Charge > No Battery Life Mode.

I tried various Chargers, No luck
I tried Resetting, No Luck

In the end the charge light wouldn't come on at all.
Checked Cable but OK.

In desperation I plugged it into the computer USB socket and left it.
Well, at least it started charging again, but little battery life.
Would not reset.

At last, I tried putting it into the computer socket and waiting till the charging light came on and the book opened.

Then, and this is the important bit, I reset the Reader
*** WITHOUT UNPLUGGING FROM THE COMPUTER ***
For me only a soft reset was necessary, but you may have to do this more than once.

That finally did the trick and the battery life is quite back to normal.
Switched off the WiFi, a week's reading and I still have all four bars on the battery meter.

Hope this may help a few folks!

StamosD

[GeckoFriend]

Very interesting; this will be the next thing I try if my battery problem isn't fixed.

[carpetmojo]

Interesting ......

[pssquirrel]

Originally Posted by StamosD

... At last, I tried putting it into the computer socket and waiting till the charging light came on and the book opened.

Then, and this is the important bit, I reset the Reader
*** WITHOUT UNPLUGGING FROM THE COMPUTER ***
For me only a soft reset was necessary, but you may have to do this more than once.

That finally did the trick and the battery life is quite back to normal.
StamosD

Interesting, indeed! When you plugged your Reader into your computer and did the soft reset, was the Reader in reading mode or Data Transfer mode?

[StamosD]

I reset in reading mode, not data transfer.

I suspect that the Reader does not like being re-charged too often by a Charger.
Some are crude, unregulated and really only suitable for recharging nickel metal hydride batteries. They put out a higher voltage which floats down according to load. It is possible that a protective circuit in the reader might be triggered by the initial high voltage.
Some are regulated and put out a steady 5V 500ma like a USB port on a computer.
Some are made and optimised for recharging Lithium Ion batteries, they have a charging Cycle built in. You recognise these as they normally have a light that starts on charging and goes out at the end of the cycle. Sounds familiar? Yes, there is just such a charge manager within your Reader controlling the charge light. In this case, who's in charge? Must be a conflict for certain.

And when the Cable is plugged in for recharge to the computer, is there exchange of control info? Of course you have to tell the reader you are not using the cable as comms, but then what? Is there recharging info going across?

I don't know, but I didn't get a charger with my reader, you are supposed to use a computer, not someone else's charger.

StamosD

[bla]

THere is an "offical" PRS T1 wall charger -PRSAAC10 obtainable from Best Buy,($29.99 in Canada I would suggest you use that ,just to be safe"if you don't want to use the USB, I am aware that various other chargers seem to work but over time they may damage the charging circuit.

[elcreative]

Originally Posted by StamosD

I reset in reading mode, not data transfer.

I suspect that the Reader does not like being re-charged too often by a Charger.
Some are crude, unregulated and really only suitable for recharging nickel metal hydride batteries. They put out a higher voltage which floats down according to load. It is possible that a protective circuit in the reader might be triggered by the initial high voltage.
Some are regulated and put out a steady 5V 500ma like a USB port on a computer.
Some are made and optimised for recharging Lithium Ion batteries, they have a charging Cycle built in. You recognise these as they normally have a light that starts on charging and goes out at the end of the cycle. Sounds familiar? Yes, there is just such a charge manager within your Reader controlling the charge light. In this case, who's in charge? Must be a conflict for certain.

And when the Cable is plugged in for recharge to the computer, is there exchange of control info? Of course you have to tell the reader you are not using the cable as comms, but then what? Is there recharging info going across?

I don't know, but I didn't get a charger with my reader, you are supposed to use a computer, not someone else's charger.

StamosD

The reader doesn't actually care about anything - it's an object... if you use cheap and faulty chargers then it's not exactly a surprise that there are problems but a decent charger will work fine and as many times as you want to use it... 5V & 500mA is the standard USB rating and should be regarded as the minimum for use but 500-2000+mA is fine and the higher current will give a faster charge within the limits of current drain regulated by the reader... oh yes, the computer usage as you don't get a charger = minimum case not "supposed to use..."

[SueBear]

The charging circuit may need to be rebooted same as the device needs from time to time. I remember that was how I got my first Palm (m130) at a bargain price because the only thing wrong with it was that it wouldn't hold a charge. Swapping out the battery? No help. Found directions like these above on line for rebooting the charging circuit and bingo - shiny new perfect PDA. Those instructions required a hard reboot while in the charging cradle, strangely similar, don't you think? Thanks for posting this - tucking it away for a rainy day!

[MCSmarties]

Interesting, thanks.

I have also used the Battery Calibration app on my (rooted) reader to fix that.

[StamosD]

Trust me, it isn't an object, it is an intelligent comms device that controls its charging cycle.
I know, I hold a Masters Degree in Electrical engineering from Cambridge University.
Follow my advice.
As a relevant digression, consider why Toyota's Hybrid batteries (originally guaranteed for 8 years) have been lasting 10 years and 250,000 miles while still being able to maintain 80% charge.
This is because their charging cycle was 'over designed' and limited the amount the batteries are allowed to discharge (20%), the amount the batteries are allowed to charge (80% capacity) and the charging rate.
Always follow the manufacturer's instructions.

Stamos D

Originally Posted by elcreative

The reader doesn't actually care about anything - it's an object... if you use cheap and faulty chargers then it's not exactly a surprise that there are problems but a decent charger will work fine and as many times as you want to use it... 5V & 500mA is the standard USB rating and should be regarded as the minimum for use but 500-2000+mA is fine and the higher current will give a faster charge within the limits of current drain regulated by the reader... oh yes, the computer usage as you don't get a charger = minimum case not "supposed to use..."

[uboot]

you're right.

all chargers are dumb.

it is the reader that controls charge current. and monitors battery temperature. otherwise it would explode.

but some chargers are so dumb (i.e. non-standard) that the reader does not recognize if it supports hi speed charging (i.e. current >500mA). (for this to happen, there has to be 0...200Ohm resistance between usb data pins).

there are some reports in the forum that a charger with at least 1000mA results in longer battery life.

[elcreative]

Originally Posted by StamosD

Trust me, it isn't an object, it is an intelligent comms device that controls its charging cycle.
I know, I hold a Masters Degree in Electrical engineering from Cambridge University.
Follow my advice.
As a relevant digression, consider why Toyota's Hybrid batteries (originally guaranteed for 8 years) have been lasting 10 years and 250,000 miles while still being able to maintain 80% charge.
This is because their charging cycle was 'over designed' and limited the amount the batteries are allowed to discharge (20%), the amount the batteries are allowed to charge (80% capacity) and the charging rate.
Always follow the manufacturer's instructions.

Stamos D

Congratulations on having a Masters... that doesn't mean that you're right about everything though... "You're supposed to use a computer..." Sorry that is minimum recommendation not essential necessity otherwise the device manufacturer's wouldn't make an INDEPENDENT PSU... and the charging cycles are controlled by the device not the PSU...

Yes, some cheap PSUs can fry your device but the regulation for them refers to not allowing spikes and other irregularities in the output... not to controlling the charge levels other than to have hi-speed charge ID as uboot says...

And there is no such thing as an intelligent comms or other electronic device, simply one that meets pre-programmed conditions - this is not intelligence...

And I would also point out that the only time, I use a computer for charging, is when I plug the reader(s) in for file transfer occasionally otherwise I ONLY charge by external charger... and my earliest eReader (PRS 505 bought new on release) is still charging and working perfectly after years of daily usage with a variety of mains chargers providing a currents ranging from 750mA to 2A...

[uboot]

don't wanna repeat myself - much has been already posted in other threads - but for lazy bones / search function rejectors here's a bunch of links:

https://wiki.mobileread.com/wiki/PRST...roper_Charging
https://www.mobileread.com/forums/sho...88#post1851988
https://www.mobileread.com/forums/sho...d.php?t=160044
https://wiki.mobileread.com/wiki/PRST..._wall_chargers

[AnotherCat]

Originally Posted by StamosD

My Sony PRS-T1 went into the Empty > Charge > Short Battery Life then the Empty > Charge > No Battery Life Mode....

...etc

I did not know how to respond to this before, having been unsure of your now disclosed electronics background. But now I know I will pass on my general observations re the T1 USB/Charging side in case they add anything to your thoughts:

First, the T1 is the first USB charged device I have bought that did not come with an AC charger in the pack so their expectation is, as you have said (which for reasons I don't understand has raised the ire of one poster?), that users will generally use their PC USB port as the downstream charging port. Unfortunately the T1 Service Manual gives no detail as to the devices used in the T1 (and I have never dismantled one :-)) but I assume an integrated USB transceiver/charger is used or those in separate packages in which case the T1 likely complies with the USB Implementers' Forum's Battery Charging Specification.

As far as I know, Sony were not a contributer to that specification but Nokia were, and implemented much (or all?) of it for a number of years before it was finalised (I think their first USB charged phone came out in 2007?). I have used Nokia USB charged devices for some years and the T1's charging behaviour is very similar to theirs. Some users of earlier Nokia phones, anecdotally, had similar problems as to those being mentioned by some T1 users, and seemed mainly to be related to the Weak Battery Algorithm failing into a Not Ready to Connect loop, or similar glitch in the T1's charging intelligence and finding some way to force a way out of that. Your soft boot on charge solution seems to maybe point in a similar direction for the T1 as a means to force these sorts of issues.

Regarding chargers --- it seems from anecdotal evidence, that if a dedicated charging port is used for the T1 then D+ and D- need to be shorted at that port. All my dedicated chargers comply with the USB Implementers' Forum's specification so I have not been able to test this with a non complying one without them shorted, but while it is difficult to make assumptions about the T1's charging from unsophisticated forum users's anecdotal (and often plainly incorrect) comments, this does seems to be a pretty much demonstrated requirement and so also points to the T1's compliance with the specification.

Like most device manufacturers for a dedicated charging port Sony only recommend their own AC charger - unfortunately I have never found any detailed specifications for the Sony charger but expect it does not enumerate the downstream device (the T1) as it seems D+ and D- are definitely shorted in the charger (200 ohm max being allowed in Specification complying chargers) or in its captive cable's Micro-B plug as required by the Implementers' specification. In which case, assuming compliance with the Implementers' Spec., it will comply with that specification's load voltage and load current shutdown requirements and maximum D+D- leakage current. I would assume from that any charger used from the wild that does not comply within the Specification's max. D+D- leakage current requirement may fail as may any whose output falls into the "Charging Port Operation not Allowed" part of the voltage vs current graph in the Specification (charger operation not allowed if voltage falls below 4.75v for I=<0.5A I believe).

[Suffolk Punch]

Originally Posted by StamosD

Then, and this is the important bit, I reset the Reader
*** WITHOUT UNPLUGGING FROM THE COMPUTER ***
For me only a soft reset was necessary, but you may have to do this more than once.

In reading mode how did you reset the T1 exactly?

Did you press the reset button, and then the power button?
Or did you go to Settings > Initialisation > Restore defaults?
Or something else?