Glo Battery Depletion?

[kobokobe]

Originally Posted by TechniSol

You do realize that SLEEP mode eventually results in OFF mode?

No offense, but sleep mode consumes more power than "off". In sleep mode the contents of the RAM are preserved, RAM must be powered and refreshed continuously. The off mode is a deeper sleep mode without dynamic refresh of the RAM or the unit could start up exactly where you left off, as an option, instead of booting. In OFF mode it is likely only looking for input from the multimode power switch and maintaining time/date functions and performing whatever minimal "housekeeping" that must be maintained.

However, if you allow the reader to repeatedly sleep then shut off during use and reboot a lot, especially with a lot of ebooks loaded, it may in fact draw more power because it has to scan the titles stored and process them each time you boot. You'd be better off waking it from sleep before it gets to OFF mode as it would only cost a page refresh, rather than costing a reboot over the SLEEP mode cost.

You really have to set the Sleep and Power settings to match your usage patterns to extract the maximum run time. Honestly, if you end up allowing the unit to go to OFF mode a lot your only recourse would be to change your own usage patterns if you want longer battery life as Kobo apparently feels that going longer than 60 minutes in sleep should force the OFF mode as there is no way to completely disable it. It's quite likely that the average reader settles in for a longer continuous period of reading than a series of short periods of reading interrupted by longer periods of OFF time. You also must run the battery down occasionally to calibrate the power gauge if you're getting less than expected runtimes.

No offense, but is this not pretty much what I said (if this post was directed at me)?

Either way, I have no clue what you mean by "You do realize that SLEEP mode eventually results in OFF mode?" and "Kobo apparently feels that going longer than 60 minutes in sleep should force the OFF mode as there is no way to completely disable it" You can set auto-off to never?

[SaraHannaOrigina]

Mine doesn't turn OFF automatically. You can change it to shut itself off after a certain amount of time, but mine have all come "out of the box" with the option "Never" selected. I have never changed that. I find I hardly lose any charge at all in sleep mode. So go ahead and act all self righteous, however I know for a fact (speaking with several reps at Kobo) that Sleep mode doesn't use any power because of the E-Ink technology. Of course I can't seem to find anything about that in their help section online, but there you go.

[SaraHannaOrigina]

Originally Posted by TechniSol

Hey, just a thought, but if you've sideloaded an epub that the Kobo can't process for some reason it's going to continue using power trying to process that file, over and over again.(not sure that is continuous, probably just at each boot?) There are threads in the forum where users have found removing the offending ebook, and sometimes processing it through Calibre prior to reloading it helped, as I recall.

Hmmm... perhaps you should take the time to read all posts in a thread before you comment. *headshake*

I have already unlocked the epubs through Calibre and reformatted them the way I wanted them. So my books had nothing to do with the crappy battery on my last model. It was simply defective. Otherwise, there would also have been a battery issue with my first one, and as I mentioned, there was actually nothing wrong with it... it lasted a full 10 days on a single charge and had only depleted to 63% power (including being in sleep mode overnight every night).

[davidfor]

Originally Posted by TechniSol

Hey, just a thought, but if you've sideloaded an epub that the Kobo can't process for some reason it's going to continue using power trying to process that file, over and over again.(not sure that is continuous, probably just at each boot?) There are threads in the forum where users have found removing the offending ebook, and sometimes processing it through Calibre prior to reloading it helped, as I recall.

New books are only processed when the device is disconnected from USB. A bad book will only affect the power usage at that time, not later.

[TechniSol]

A few observations for the peanut gallery:

First, on my unit I only have options for between five and sixty minutes for both sleep and power. Perhaps because it is a "special offers" unit, or because I foolishly changed them from "Never", if I indeed had such an option, thinking that said option would still exist in the drop downs.

{Shakes Head Right Back At You} Second, I do, in fact, read EVERY post of threads, however my brain is occasionally turned to mush due to prattle and by people who insist on FACT by virtue of authority, having never taken the time to determine the inner workings of technology for themselves. Pardon my taking the trouble to address an issue you apparently were not actually confronted with, but it was rather hard to rule out the possibility that you hadn't loaded a wonky ebook on one of the later machines which was consuming excessive power. OTOH, the one sure thing about free advice is that you often get value commensurate to what you paid.

Third, whether someone actually told you that your reader consumes no power because of the E-ink display in SLEEP MODE or you merely inferred it based on being told that an E-ink display only consumes power while updating, you're wrong in thinking the ereader as a unit consumes no power in SLEEP or OFF modes.

I have designed microcontroller based circuitry for nearly a decade, and microprocessor based control systems for even longer and I can assure you more power is consumed in SLEEP MODE than ultra low power modes generally referred to as OFF because in SLEEP contents of RAM must either be preserved with dynamic refresh which requires power, stored in Static RAM which requires power, or stored to & read from non-volatile memory upon entering/leaving SLEEP modes.(technically referred to most often as hibernation)

Sara -if you'll take the time to consult your own huffy little rejoinder above you might note that you simultaneously maintain:

"I find I hardly lose any charge at all in sleep mode."

"Sleep mode doesn't use any power because of the E-Ink technology."

So which is it, "hardly lose any charge" or "doesn't use ANY power"? I'll bet you it's the former. And yes, the two are contradictory.

[speakingtohe]

Originally Posted by davidfor

New books are only processed when the device is disconnected from USB. A bad book will only affect the power usage at that time, not later.

I can see that although some books seem to consume more power per page turn when reading than others? I have had books with approximately the same number of pages (approximately 200) deplete the battery as little as 1% per 100 pages or 270 page turns and as much as 4%. I often check 1/2 way through a book and at the end because I am curious.

Helen

[kobokobe]

Originally Posted by TechniSol

A few observations for the peanut gallery:

First, on my unit I only have options for between five and sixty minutes for both sleep and power. Perhaps because it is a "special offers" unit, or because I foolishly changed them from "Never", if I indeed had such an option, thinking that said option would still exist in the drop downs.

{Shakes Head Right Back At You} Second, I do, in fact, read EVERY post of threads, however my brain is occasionally turned to mush due to prattle and by people who insist on FACT by virtue of authority, having never taken the time to determine the inner workings of technology for themselves. Pardon my taking the trouble to address an issue you apparently were not actually confronted with, but it was rather hard to rule out the possibility that you hadn't loaded a wonky ebook on one of the later machines which was consuming excessive power. OTOH, the one sure thing about free advice is that you often get value commensurate to what you paid.

Third, whether someone actually told you that your reader consumes no power because of the E-ink display in SLEEP MODE or you merely inferred it based on being told that an E-ink display only consumes power while updating, you're wrong in thinking the ereader as a unit consumes no power in SLEEP or OFF modes.

I have designed microcontroller based circuitry for nearly a decade, and microprocessor based control systems for even longer and I can assure you more power is consumed in SLEEP MODE than ultra low power modes generally referred to as OFF because in SLEEP contents of RAM must either be preserved with dynamic refresh which requires power, stored in Static RAM which requires power, or stored to & read from non-volatile memory upon entering/leaving SLEEP modes.(technically referred to most often as hibernation)

Sara -if you'll take the time to consult your own huffy little rejoinder above you might note that you simultaneously maintain:

"I find I hardly lose any charge at all in sleep mode."

"Sleep mode doesn't use any power because of the E-Ink technology."

So which is it, "hardly lose any charge" or "doesn't use ANY power"? I'll bet you it's the former. And yes, the two are contradictory.

Sleep mode does inevitably use power, if for nothing else, for the RAM that remembers the page you were on, etc, like the post mentioned. What everyone's wondering and has discussed quite extensively in the past, is how much battery it consumes while sleeping, how much when off (battery does slowly deplete when off for every electronic device I can think of, don't know the reason behind it like the quoted poster, but you can clearly see that the battery level has dropped if you turn on an electronic device after a period of "off"), and how much it uses during the process of turning the device back on from "off".

My opinion is that, especially on the Glo, the battery usage during sleep mode is negligible enough that it doesn't warrant a full shut down, unless (probably) you know you won't be using it for at least a day or two.

[the.Mtn.Man]

Originally Posted by dakini

iirc the batteries these days are roughly good for about 1000 charges ... another reason to let them drain as much as possible before charging them again ...

That's actually referring to full discharge/recharge cycles, that is going from 100% until the device shuts off. "Topping up" a partially drained battery doesn't have the same effect. Think of it as several partial cycles are equivalent to one full cycle. There's usually no reason to completely drain a rechargeable battery before recharging it.

[davidfor]

Originally Posted by the.Mtn.Man

That's actually referring to full discharge/recharge cycles, that is going from 100% until the device shuts off. "Topping up" a partially drained battery doesn't have the same effect. Think of it as several partial cycles are equivalent to one full cycle. There's usually no reason to completely drain a rechargeable battery before recharging it.

I have to correct the last bit. It depends on the type of rechargeable cell. The battery in the Kobo devices are Li-Ion. These don't need to be completely discharged before recharging. But something like a NiCad or NiMH should be.

[Danger]

Just a bit more from the peanut gallery regarding only sleep vs sleep -> off.

From personal experience having my Kobo (Touch) in sleep only mode drains the battery much faster than sleep then power off. Currently I have mine set to sleep after 15mins then power off after 30 mins. I once had it set to sleep after 15mins power off after 60mins and even then I noticed a difference in battery drain. The books I read are all sideloaded epubs on an SD card. I can usually get about 3 weeks worth on a charge, reading about 2-4 hours a day with my current settings. If I remember correctly when I had it set to sleep only, I got about a week and a half out of the charge.

[TechniSol]

My apology to the forum, et al, for the peanut gallery crack. I'm afraid it gets my hackles up when people get snarky when others are just trying to help, and then when they start spouting secondhand BS as fact instead of indicating opinion it really punches my buttons. But it seems I may have been inadvertently guilty of thue same since others have a "never" option for sleep and powering off and I don't. No excuse for my poor behavior, just by way of explanation.

Considering the variety of differences that abound apparently even under the same firmware version I guess we all need to consider that before arguing. He said, rather lamely...

I've never designed a battery powered device intended to use Lithium Ion or polymer tech, largely because a greater possibility of serious damage exists if a problem occurs during charging and because I never really needed the higher power density. I like NiMH. However, from what I've read, most manufacturers say something along the lines of 500-1000 cycles for Lithium Ion/polymer. The reasoning being that deep cycles tend to be harder on the cells than shallower cycles which you can get more of... It's also apparently good to avoid charging until they're discharged a bit in order to avoid constant recharge cycles based on my laptop offering an adjustable "deadzone" whereby it won't start another charge cycle until the battery drops below 95% to limit unnecessarily shallow cycles... Frankly, they're complicated.