Basic questions about ereader!

[maindoor]

Hi,

Can someone answer a couple general questions about e-readers:

1) e-ink pearly display: If it is true that only the page turning consumes
battery, can we store it in the on-state and continue reading say next-day,
without wasting battery ?
The processor must run, so I think it will consumer power.

2) What is the estimated life of an e-ink pearl display ? in terms of page-turns etc.
For example keys in a keyboard lives for about 5-10million clicks.
LED displays are in the range of about 50,000 hrs. etc.

Thanks.

[Billi]

Originally Posted by maindoor

1) e-ink pearly display: If it is true that only the page turning consumes
battery, can we store it in the on-state and continue reading say next-day,
without wasting battery ?
The processor must run, so I think it will consumer power.

Yes, the processor runs and it consumes power. It is only a very small amount because it will go into some kind of sleep mode, but nevertheless.

The screen only consumes power when it "builds up" the next page while page turning, the "showing" itself doesn't need power.
How many power will be consumed in sleep mode differs from reader to reader.

[HarryT]

As Billi says, the power used in sleep mode varies significantly between devices. The Amazon Kindle, for example, uses essentially zero power in sleep mode; you can leave it asleep for two weeks, and when it wakes up the battery level will be the same as it was when it went to sleep. Other devices do use a noticeable amount of power when asleep.

I don't think anyone knows the lifetime of an eInk display, other than that the oldest eInk displays, which are now about 6 or 7 years old, are still working just fine.

[jocampo]

Not much to say here ...

I think Harry and Billi answered your question.

But basically, as long as the ereader is in sleep mode and wifi or 3G (if available on your device) was turned off, there is zero or very low battery consumption. The battery is used mainly when turning or refreshing pages. That's why they are so good on that. It is different on LCD devices, which regardless of the page you are, keep it on will and is consuming battery all the time, until you turn the device off or goes to sleep.

The life of an eink device is more tied up to the protection of the screen. The device itself can last several years without any issue if you don't break it.

[HarryT]

Originally Posted by jocampo

But basically, as long as the ereader is in sleep mode and wifi or 3G (if available on your device) was turned off, there is zero or very low battery consumption.

That's not true in every case, Jo. When I had a Cybook Opus, for example, the battery would drain in about 10 days when the device was asleep. It's something which varies considerably between devices.

[jocampo]

Originally Posted by HarryT

That's not true in every case, Jo. When I had a Cybook Opus, for example, the battery would drain in about 10 days when the device was asleep. It's something which varies considerably between devices.

You are correct.

I actually made my comment based on my experience with Kindle which honestly, it is very good in terms of battery.

But in general terms, eink devices consume less batery than LCD.