Energy consumption of Cybook Gen 3

[Kaero]

I did some measurements of the Cybook Gen 3 and calculated some energy consumptions. You can download the result from here:
Cybook_Gen_3_Energy_consumption.pdf

Shortly, one can do only about 3000 page flips for one fully loaded battery. Probably less. And the device is able to be switched on (without pressing any key or automatical switching off) less than 60 hours with firmware 708 or 40 hours with firmware 658.

I would appreciate any commnets (any error of mine is possible ). I would also appreciate any real world data - e.g. if someone counted real page flips (or computed from some book), or measured the time till battery runs out etc.

[tompe]

Originally Posted by Kaero

Shortly, one can do only about 3000 page flips for one fully loaded battery. Probably less. And the device is able to be switched on (without pressing any key or automatical switching off) less than 60 hours with firmware 708 or 40 hours with firmware 658.

The time for version 708 is stil much less than for version 538 which lasted around 100 hours. This is bad. They probably just adjusted some parameter to raise the time from 40 to 60 hours and did not fix the underlying problem.

[Kaero]

Originally Posted by tompe

The time for version 708 is stil much less than for version 538 which lasted around 100 hours. This is bad. They probably just adjusted some parameter to raise the time from 40 to 60 hours and did not fix the underlying problem.

I can compare 658 and 708, but to calculate the total time I made extrapolation, which is never good. So, first I need some confirmation that my calculations are correct. After this, It would be possible to make such comparison you made with other peoples results.

One of the reasons (beside the fact it was fun ) I did these measurements was the thought: should I switch off the device for 40 minutes, or let it on? And what about 20 minutes long pause between readings? I measured that the processor in sleeping mode for 15 minutes consumes the same energy as the switch off, swtich on and loading a book. So for longer reading pause, it is better to switch off the device completely.

[tompe]

Originally Posted by Kaero

I can compare 658 and 708, but to calculate the total time I made extrapolation, which is never good. So, first I need some confirmation that my calculations are correct. After this, It would be possible to make such comparison you made with other peoples results.

Aha, I am testing mine with 708 now (started 00.30 today Saturday) so I will know in a couple of days how long it lasts.

[JSWolf]

Originally Posted by Kaero

I did some measurements of the Cybook Gen 3 and calculated some energy consumptions. You can download the result from here:
Cybook_Gen_3_Energy_consumption.pdf

Can you redo your measurements without an SD card? The new Gen3 has 512megs of of ram which is definitely enough to not actually need to have an SD card installed. The SD care does eat up extra battery. So getting test results without such would give us a better understanding of how it works. The results with the SD card really are not accurate enough.

[tompe]

Originally Posted by JSWolf

Can you redo your measurements without an SD card? The new Gen3 has 512megs of of ram which is definitely enough to not actually need to have an SD card installed. The SD care does eat up extra battery. So getting test results without such would give us a better understanding of how it works. The results with the SD card really are not accurate enough.

What do you mean "accurate enough"? The value of 4-5 days we have to compare with is with SD card.

[delphidb96]

Originally Posted by tompe

The time for version 708 is stil much less than for version 538 which lasted around 100 hours. This is bad. They probably just adjusted some parameter to raise the time from 40 to 60 hours and did not fix the underlying problem.

I was wondering about that... You see, after all the weird keypress issues I had with Build 685, I 'downgraded' to Build 538. And I noticed my battery life increased when I did so.

Well, having Build 705 installed, I've seen no evidence of the keypress issues I had before, but I *thought* my battery life had gone down. Glad to see that I'm not just imagining things.

Granted, 60 hours is still a lot longer than 4 hours - which is what I was getting with my Dell Axim x51v - but I'm no longer getting anywhere near as many page-flips under 705 than I did under 538.

Derek

[Kaero]

Originally Posted by tompe

Aha, I am testing mine with 708 now (started 00.30 today Saturday) so I will know in a couple of days how long it lasts.

without touching the cybook? the most usable info for me would be the on time without even touching the keyboard, but the problem is how you know the device is out of battery? :|

Anyway, ratios (e.g. energy of page up versus energy of start up) of my measurements should be quite accurate. So if I will know some real world value, I can use it to calibration of other results.

Originally Posted by JSWolf

Can you redo your measurements without an SD card?

Yes, i can redo all measurements. But it takes a lot of time (most of it is the work with data). I was considering to measure without SD card, but I've read few times the card doesn't have influence. So if someone will measure on time with card and without (and it will be different), I will measure everything once again

[delphidb96]

Originally Posted by JSWolf

Can you redo your measurements without an SD card? The new Gen3 has 512megs of of ram which is definitely enough to not actually need to have an SD card installed. The SD care does eat up extra battery. So getting test results without such would give us a better understanding of how it works. The results with the SD card really are not accurate enough.

Unfortunately, I have a 64MB model. Which means that I *have* to have an SD card in order to carry around the number of titles I'm used to... [Sigh].

Derek

[JSWolf]

Originally Posted by tompe

What do you mean "accurate enough"? The value of 4-5 days we have to compare with is with SD card.

I mean if you purchase a new Gen3 now, you'll get one with 512meg which is enough internal memory to carry around a number of eBooks. Using the SD card does take extra power from the battery. So measuring he power consumption without the SD card is a good idea. Even if just to see what the difference is. My 505 can take an SD card, but I don't use one so I can get more life out of the battery.

[JSWolf]

Originally Posted by Kaero

Yes, i can redo all measurements. But it takes a lot of time (most of it is the work with data). I was considering to measure without SD card, but I've read few times the card doesn't have influence. So if someone will measure on time with card and without (and it will be different), I will measure everything once again

Thank you. That would really show what battery life can be like with the newer model that does not need an SD card.

[tompe]

Originally Posted by JSWolf

I mean if you purchase a new Gen3 now, you'll get one with 512meg which is enough internal memory to carry around a number of eBooks. Using the SD card does take extra power from the battery. So measuring he power consumption without the SD card is a good idea. Even if just to see what the difference is. My 505 can take an SD card, but I don't use one so I can get more life out of the battery.

Yes, but that will not help you to compare with previous firmware since the new version does not work with old firmware. I doubt there will be much difference but if I feel curious I will test. Anybody know the typical rest power consumption for an SD card?

[HarryT]

How's your test going, Tommy? It's been about 40h so far, hasn't it? What's the battery charge down to?

[tompe]

Originally Posted by HarryT

How's your test going, Tommy? It's been about 40h so far, hasn't it? What's the battery charge down to?

80% so maybe I will get 4 days...

[HarryT]

Sounds good!