AURA H2O battery life - Page 4

rwhe · 11-11-2014, 01:02 PM

Quote:

Originally Posted by rwhe

From an old thread:

"I've heard someone mention elsewhere on this forum that if you have an SD card installed the charge doesn't last as long since each time you start your KT from power-off mode it goes to check through the SD card using some power. Also understandably, the more files you have on the card the more power it consumes each time."

I should add that having my H2O power down after 30 or 60 minutes didn't seem to be saving any energy; in fact, there seemed to be a significant drop every time I powered it back up. Also, my SD card has close to 1000 titles on it.

93terp · 11-11-2014, 08:52 PM

Quote:

Originally Posted by rwhe

From an old thread:

"I've heard someone mention elsewhere on this forum that if you have an SD card installed the charge doesn't last as long since each time you start your KT from power-off mode it goes to check through the SD card using some power. Also understandably, the more files you have on the card the more power it consumes each time."

That makes perfect sense to me.

rwhe · 11-13-2014, 03:45 AM

Still getting wacky readings from my battery meter. Going to try calibrating my H2O, on the advice of a couple of other threads in this forum. I found a good article on calibrating your laptop battery, much of which can probably be applied to calibrating a Kobo. Some excerpts follow.

Charge your laptop’s battery to full — that’s 100%.
Let the battery rest for at least two hours, leaving the computer plugged in. This will ensure that the battery is cool and not still hot from the charging process. You’re free to use your computer normally while it’s plugged in.
Pull the power plug and leave your computer discharging until it automatically sleeps or hibernates. You can keep using your computer normally while this happens.
Allow your computer to sit for five hours or so after it automatically shuts down.
Plug your computer back into the outlet and charge it back up to 100%. You can keep using your computer normally.

Kobo forums recommend at least two sequential calibration cycles.

[edit] ...but I haven't seen anyone other than samhy recommend two full cycles. More like one and a half: charge fully, discharge fully, charge fully again, use normally. samhy, what is the source of your information?

Battery University has a good article on battery calibration with more meat than most.

Chi Cygni · 11-14-2014, 12:19 PM

12 full days for me. Charged on November 2, it died today after heavy reading, wifi off mostly, no sync, light on, 3 books read I think and playing around. It's fine by me. Much longer than PW. It is charging right now from 0, black screen with battery on it.

rwhe · 11-17-2014, 07:28 PM

After calibrating my battery once -- I'm in the middle of a second calibration -- I'm seeing a more even battery drain with fewer wacky readings, and that's finally making it possible to measure the drain under different conditions. Reading with the light on near max seems to drain 8-10% per hour. Reading with the light off seems to drain only about 2% per hour on my H2O. That makes Kobo's claimed reading time of "up to" 30 hours for the H2O seem more plausible to me. (Of course, you've read "up to" 30 hours on your Kobo before you even unbox it, but you probably don't need a lesson in marketing language from me.)

So, thanks to others in this thread, my strategy for saving battery includes the following so far:

* Calibrate the battery.
* Don't use an SD card, especially one containing a lot of titles.
* Don't use the light unless necessary, at least at high power levels.
* Use wifi, especially syncing, as little as possible.

I was doing the opposite of this advice in pretty much every case. At this point, I'm going to keep monitoring my battery, but it's not yet worth the nuisance to return my H2O for a new unit.

Any other recommendations for saving power?

meeera · 11-18-2014, 12:09 AM

Quote:

Originally Posted by rwhe

Any other recommendations for saving power?

The main one is keeping Wifi off, but to be honest, I don't bother. I don't go camping for long periods away from a power source, so if I have to recharge every 4-7 days instead of every 2-3 weeks, I'm just not bothered.

rwhe · 11-18-2014, 01:55 AM

Quote:

Originally Posted by meeera

The main one is keeping Wifi off, but to be honest, I don't bother. I don't go camping for long periods away from a power source, so if I have to recharge every 4-7 days instead of every 2-3 weeks, I'm just not bothered.

Thanks, and let's not forget that setting it to refresh the screen after more pages saves more power.

The first battery calibration went really well. I want to drain the battery completely again so I can finish this second calibration cycle, load my Kobo up with some new books, and move onward from this tragic episode. Unfortunately (?), although I have the light on at 100%, the wifi on, I'm refreshing after every page, and I've synced four times in the last hour, I can't seem to drain it any further than 31% (starting at 44%).

rwhe · 11-18-2014, 03:21 AM

It seems the elements of a Kobo Battery FAQ are coalescing in this thread. Would anyone like to see one?

HarryT · 11-18-2014, 03:39 AM

Quote:

Originally Posted by rwhe

Thanks, and let's not forget that setting it to refresh the screen after more pages saves more power.

No, if you set the screen to refresh after more pages it will use less power. ie, setting the screen to refresh after 6 pages will use less power than setting it to refresh after every page.

rwhe · 11-18-2014, 11:46 AM

Quote:

Originally Posted by HarryT

No, if you set the screen to refresh after more pages it will use less power. ie, setting the screen to refresh after 6 pages will use less power than setting it to refresh after every page.

That's what I meant. It uses less power, so it saves more power.

HarryT · 11-18-2014, 11:53 AM

Quote:

Originally Posted by rwhe

That's what I meant. It uses less power, so it saves more power.

Apologies - I misread your post.

jackastor · 11-18-2014, 03:13 PM

Quote:

Originally Posted by rwhe

It seems the elements of a Kobo Battery FAQ are coalescing in this thread. Would anyone like to see one?

H*ll Why not! Run with it!

Rizla · 11-18-2014, 10:34 PM

Delete all books and do a soft reset. A bad epub can cause instability and battery drain.

93terp · 11-29-2014, 08:44 AM

Finally got to the 10% battery warning message last night. I believe I had about 75 hours of reading on the device before I got to the 10% battery level. Made it almost 2 months on a charge. Very impressed!

Quote:

Originally Posted by 93terp

The last time I charged my H2O was 10 October. Since then, according to Reading Stats I have read 60 hours. During these 60 hours I have intermittently used the light, at no more than 30%. I have not used WiFi or done any syncs on the device. I have my the unit set to automatically go to sleep after 30 minutes, and automatically power off after 60 minutes. My battery is at 54%. Either have a wacky meter or I got a super exceptionally good H2O!

jim.1405 · 11-29-2014, 11:38 AM

The battery life on my H2O has been most impressive. Even though it is rated the same as the PW2 it replaced I'm finding the battery life to be far superior. I've been using it since the last week of Oct and when I recharged it last night it still had 39% charge left.

I generally read about and hour a day although some days it may be several hours and other days I don't read at all. It was plugged into the laptop a few times to load books but only for a few minutes each time so it got a small boost but not much.

I don't use WiFi at all and the light level is kept at constant 39%.

Overall I'm quite happy with the H2O. I do wish it were a little snappier when navigating through the menus and the top edges could be a little more rounded for better holding comfort (I use the reader with no case). But these are minor quibbles. The screen is beautiful and lighting very even which are the most important aspects to me.

11-13-2014, 03:45 AM	#48
rwhe Hierodule Posts: 170 Karma: 629686 Join Date: Mar 2010 Device: Kobo Glo, calibre, Android, FBReader	Still getting wacky readings from my battery meter. Going to try calibrating my H2O, on the advice of a couple of other threads in this forum. I found a good article on calibrating your laptop battery, much of which can probably be applied to calibrating a Kobo. Some excerpts follow. Charge your laptop’s battery to full — that’s 100%. Let the battery rest for at least two hours, leaving the computer plugged in. This will ensure that the battery is cool and not still hot from the charging process. You’re free to use your computer normally while it’s plugged in. Pull the power plug and leave your computer discharging until it automatically sleeps or hibernates. You can keep using your computer normally while this happens. Allow your computer to sit for five hours or so after it automatically shuts down. Plug your computer back into the outlet and charge it back up to 100%. You can keep using your computer normally. Kobo forums recommend at least two sequential calibration cycles. [edit] ...but I haven't seen anyone other than samhy recommend two full cycles. More like one and a half: charge fully, discharge fully, charge fully again, use normally. samhy, what is the source of your information? Battery University has a good article on battery calibration with more meat than most. Last edited by rwhe; 11-18-2014 at 03:20 AM.

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11-14-2014, 12:19 PM	#49
Chi Cygni 秋子 permanently lurking Posts: 839 Karma: 6587575 Join Date: Dec 2010 Location: Europe Device: Oasis 3, Pocketbook Era	12 full days for me. Charged on November 2, it died today after heavy reading, wifi off mostly, no sync, light on, 3 books read I think and playing around. It's fine by me. Much longer than PW. It is charging right now from 0, black screen with battery on it.

11-17-2014, 07:28 PM	#50
rwhe Hierodule Posts: 170 Karma: 629686 Join Date: Mar 2010 Device: Kobo Glo, calibre, Android, FBReader	After calibrating my battery once -- I'm in the middle of a second calibration -- I'm seeing a more even battery drain with fewer wacky readings, and that's finally making it possible to measure the drain under different conditions. Reading with the light on near max seems to drain 8-10% per hour. Reading with the light off seems to drain only about 2% per hour on my H2O. That makes Kobo's claimed reading time of "up to" 30 hours for the H2O seem more plausible to me. (Of course, you've read "up to" 30 hours on your Kobo before you even unbox it, but you probably don't need a lesson in marketing language from me.) So, thanks to others in this thread, my strategy for saving battery includes the following so far: * Calibrate the battery. * Don't use an SD card, especially one containing a lot of titles. * Don't use the light unless necessary, at least at high power levels. * Use wifi, especially syncing, as little as possible. I was doing the opposite of this advice in pretty much every case. At this point, I'm going to keep monitoring my battery, but it's not yet worth the nuisance to return my H2O for a new unit. Any other recommendations for saving power?

11-18-2014, 03:21 AM	#53
rwhe Hierodule Posts: 170 Karma: 629686 Join Date: Mar 2010 Device: Kobo Glo, calibre, Android, FBReader	It seems the elements of a Kobo Battery FAQ are coalescing in this thread. Would anyone like to see one?

11-18-2014, 10:34 PM	#58
Rizla Member Retired Posts: 3,183 Karma: 11721895 Join Date: Nov 2010 Device: Nook STR (rooted) & Sony T2	Delete all books and do a soft reset. A bad epub can cause instability and battery drain.

11-29-2014, 11:38 AM	#60
jim.1405 Member Posts: 22 Karma: 26852 Join Date: Apr 2014 Device: Kobo H2O / PW2	The battery life on my H2O has been most impressive. Even though it is rated the same as the PW2 it replaced I'm finding the battery life to be far superior. I've been using it since the last week of Oct and when I recharged it last night it still had 39% charge left. I generally read about and hour a day although some days it may be several hours and other days I don't read at all. It was plugged into the laptop a few times to load books but only for a few minutes each time so it got a small boost but not much. I don't use WiFi at all and the light level is kept at constant 39%. Overall I'm quite happy with the H2O. I do wish it were a little snappier when navigating through the menus and the top edges could be a little more rounded for better holding comfort (I use the reader with no case). But these are minor quibbles. The screen is beautiful and lighting very even which are the most important aspects to me.

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