PRS-600 what's wrong about the battery of my prs600

[gwynevans]

Originally Posted by Pierre-Olivier

So I wonder if, a power adapter would'nt be better ? Can we use the reader with an external power supply being connected ?

Yes - you just need a PSP-compatible charger (that is, one that charges via the round socket using a barrel connector, not via the USB port).

[twinszz]

Hi Everyone,

What some do not realise is that the reader should be turned "on" before hooking up to the usb on the computer, per the manual.

[Pierre-Olivier]

and what's the difference ? I don't understand exactly what you mean

[Levelpart]

Go through a full discharge/charge cycle and repeat it every few months to recalibrate the battery. Also, take a look at this article which I found pretty interesting.

How to prolong lithium-based batteries

Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.)

[Kolenka]

Originally Posted by Pierre-Olivier

and what's the difference ? I don't understand exactly what you mean

What's the difference between what and what? I don't know who you are referring to.

[elvenic]

So, if I understand this correctly, the Sony's PRS-600 battery will die after 300-400 charge-discharge cycles.

Does it mean that every time I connect/disconnect the device to the computer via USB cable, I start new charge-discharge cycle? So if I use Calibre to download newspaper feeds and connect the PRS-600 to the computer every morning to copy those feeds to the device (which means I connect/disconnect it at least once a day), will the battery die in approx. 1 year?

If I connect/disconnect the device 2 times a day, will the battery die in 6 month?

(Horror: if some day I connect/disconnect 300 times, will the battery die next morning?)

[Kolenka]

Originally Posted by elvenic

So, if I understand this correctly, the Sony's PRS-600 battery will die after 300-400 charge-discharge cycles.

Does it mean that every time I connect/disconnect the device to the computer via USB cable, I start new charge-discharge cycle? So if I use Calibre to download newspaper feeds and connect the PRS-600 to the computer every morning to copy those feeds to the device (which means I connect/disconnect it at least once a day), will the battery die in approx. 1 year?

If I connect/disconnect the device 2 times a day, will the battery die in 6 month?

(Horror: if some day I connect/disconnect 300 times, will the battery die next morning?)

No. It doesn't mean that... it is physically talking about the actual charge/discharge cycles of each cell in the battery.

If we assume the battery has one cell, and I let it run to 50%, and charge it back up, that is 1/2 a charge cycle roughly. Other behaviors will actually lengthen the life of the battery (keeping it above 50% in the case of LiIon and LiPoly batteries), and others will shorten it (deep discharging the same LiIon/LiPoly battery).

[twinszz]

Pierre-Olivier,

Some readers are hooked up to their computers, but not turned on. The reader must be turned on before hooking up to the computer in order to be read or recognized by the computer. In other words, if the reader is turned off and hooked up, the computer will not recognize the reader.

[chainring]

Originally Posted by elvenic

So, if I understand this correctly, the Sony's PRS-600 battery will die after 300-400 charge-discharge cycles.

Does it mean that every time I connect/disconnect the device to the computer via USB cable, I start new charge-discharge cycle? So if I use Calibre to download newspaper feeds and connect the PRS-600 to the computer every morning to copy those feeds to the device (which means I connect/disconnect it at least once a day), will the battery die in approx. 1 year?

If I connect/disconnect the device 2 times a day, will the battery die in 6 month?

(Horror: if some day I connect/disconnect 300 times, will the battery die next morning?)

Adding to what Kolenka has already stated, it also depends on what the final voltage the LiPo battery is at when fully charged. LiPo (Lithium Polymer), has a nominal 3.7 Volts, and is fully charged at 4.2 Volts. Most of the articles you read about LiPo cycle life being in the range of 300-500 are ones charged to the full 4.2 Volts per cell. Life can be greatly increased by backing the final Voltage to 4.1V per cell.

We can assume the PRS-600 has only one cell because the mains charger only outputs 5.2V and for two cells at 4.1V each, it would need to be at least 8.2V output -- actually more.

Here's some things you can do to lengthen battery life:
1. Do not run it fully down more than necessary. It is better to top off and let it get to no bars and recharge than it is to run it until completely dead. It appears, from various comments, that it has quite a reserve once at zero bars, so zero bars *should* be a safe cutoff point.
2. If you think it may sit for an extended period of time, run it down to three bars and use the full shutdown. LiPo cells do not respond well to being stored with a full charge, nor do they like being stored fully discharged. Not that we can measure it easily, but a LiPo cell loves being stored at approximately 3.85V.

Fact: LiPo cells start deteriorating as soon as they're manufactured and there is nothing we can do to stop it. You can slow it down by following good care habits.

[TimNeo]

I've just been counting the number of page turns I've got from a fully charged ereader putting it to sleep. I managed 612 page turns using only the buttons (no finger swiping) and putting it to sleep. There was no SD card either. It was dead after 12 days. (so light bedtime reading)

My next attempt will be to read and turn it off properly to see if there is a significant difference in battery life. Finally I'll do a marathon reading session over a weekend and see if I can get it above the 1000 page threshold.

Then I'll have some not particularly accurate data - but more real life usage from the device.

[TimNeo]

Originally Posted by HarryT

It was certainly ill-informed. Whether or not the person was deliberately and knowingly lying to you, I'll leave to your judgement. The screen uses no power while it's displaying a static image, but the Reader is a computer and, like any other computer, the CPU, RAM, etc, all use power.

Hi Harry, if they were ill informed you better let Sony know!

Originally Posted by Sony

Due to the nature of the E Ink electronic display technology, the LCD can retain an image without having power. Turning the page is the only time power is consumed. If the Reader's power is drained, the LCD will retain the last image that was displayed, thus making it appear like the Reader is frozen and in some instances it will not have enough power to perform other operations such as turning on or off.

http://support.sony-europe.com/compu...S-600&f=PA_PRS

Straight from the beasts mouth itself. Someone is wrong here... and since I'm a computer scientist, the only way that the buttons can work is via interupts which of course require power. Unless Sony has invented the most amazing electrical device ever!

I would be suprised if putting it into sleep mode caused a significant battery drain. It's well known that lithium ion batteries shouldn't be stored in a fully charged state (around 40% off the top of my head is best) for long term, but a couple of weeks shouldn't make much of a difference, especially on a device such as this.

I wouldn't be suprised if this wasn't a software issue much alike to the iPhone battery issue first generation iPhone 3G customers had.

[HarryT]

No, there's nothing wrong with that. If you read what Sony are saying, it's that the only time that the screen uses power is when the display changes. The screen uses no power when displaying a static image, but the memory, CPU, etc, all continue to do so.

[TimNeo]

I've asked the question of Sony whether they consider my page turns to be adequate output over the time of use I've given them. just over 600 page turns (even if I'd used it until entirely dead) isn't 7,500. In the meantime I live to experiment!

[HarryT]

Originally Posted by TimNeo

I've asked the question of Sony whether they consider my page turns to be adequate output over the time of use I've given them. just over 600 page turns (even if I'd used it until entirely dead) isn't 7,500. In the meantime I live to experiment!

The 7500 page turns figure comes from the screen manufacturer, and bears no resemblance to real-world usage. The way they obtain the figure is:

- Fully charge the battery.
- Turn the page as quickly as it will go, continually, until the battery is flat.

Do that, and I'm sure you'll come close to the quoted figure.

[Kolenka]

Originally Posted by TimNeo

I've just been counting the number of page turns I've got from a fully charged ereader putting it to sleep. I managed 612 page turns using only the buttons (no finger swiping) and putting it to sleep. There was no SD card either. It was dead after 12 days. (so light bedtime reading)

My next attempt will be to read and turn it off properly to see if there is a significant difference in battery life. Finally I'll do a marathon reading session over a weekend and see if I can get it above the 1000 page threshold.

Then I'll have some not particularly accurate data - but more real life usage from the device.

Well, Sony quotes 'up to two weeks' as the battery life figure. A device in sleep still drains a bit of power, and you are pretty close to that two week mark. You will never get close to the quoted 'pages before the battery dies' count doing light reading over two weeks, because then the two week barrier hits you first.

Sounds like the battery is in the expected range to me.