View Full Version : Battery Test


sfernald
11-25-2007, 01:55 PM
Ok, so I decided to perform an informal battery test on my kindle.

Quite often I go on weekend trips, and it is inconvenient to bring a charger for my reader for these trips. I just want to grab my bag and stuff and go. In the past, I have brought my sony reader and never had any worries about battery life.

So as I had a trip this weekend, I decided to bring up my Kindle (and my iphone as well) and see if I could survive the entire weekend without a charger.

Basically the trip started friday morning at 9am and extended to sunday morning at 9am.

Because I had had an issue one day with my kindle running low, I decided that I would try to "manage" the battery as best I could. So I would keep the wireless off, except for maybe 5-6 times a day when I would force content to be updated. Also, when I wasn't reading, I always tried to put the reader in "sleep" mode, and if I knew i wasn't going to be able to read for more than an hour, I would just the reader down completely. I also shut the reader down at night.

Also, I used the reader as much as I possibly could. Because I injured my back last week, this gave me the perfect excuse to do almost nothing but reading on my back. So I used the reader constantly, probably 6-8 hours a day at least and late into each night.

So it's past 9am on sunday now and the kindle has 60% charge left. Not too bad I guess. It means I could probably even squeak out a week long trip if I had to. But it confirmed that I don't have to worry about running out of batteries for my typical weekend trip. However, that was with "managing" the kindle. I'm quiet sure my kindle would have died during the trip if I had not bothered to turn off wireless and put it in sleep whenever it wasn't necessary.

Oh btw, the iphone died completely saturday night. Probably because I used it as a music player for my car on the way up!

Zoot
11-25-2007, 02:39 PM
After three days since my last charge, mine is at 50-60% indicated battery charge (for whatever that's worth).

The Kindle has been in sleep mode with the radio on the whole time, apart from maybe 3-4 hours reading time.

So far my impression is that the radio is completely off in sleep mode, the kindle is almost completely off in sleep mode, and that the radio only ever uses power when the kindle is actually on and being actively used.

I think all you need to do to get maximum battery life is to put it in sleep mode when you're not using it, and switch the radio off when you are actively using the device if you don't need web access or automatic download of subscription content.

I'm waiting for any evidence to the contrary.

Z.

gregr209
11-25-2007, 04:15 PM
Doesn't eInk only use the battery just to draw the page? The only other thing that would use the battery would be the wireless and if you used the speakers. Isn't that why the Sony Reader only states how many page turns is required per charge of the battery? I think we should be seeing a lot more battery life out of the Kindle if the wireless is turned off.

Greg

P.S. I'm still waiting for my Kindle :-(

HarryT
11-26-2007, 06:18 AM
Doesn't eInk only use the battery just to draw the page? The only other thing that would use the battery would be the wireless and if you used the speakers. Isn't that why the Sony Reader only states how many page turns is required per charge of the battery? I think we should be seeing a lot more battery life out of the Kindle if the wireless is turned off.

Greg


The screen only uses power when it's updated, but there's a lot more to a bookreader than merely the screen. The CPU, RAM, etc; all these use power. Plus of course in the Kindle's case the radio for the wireless will drawm significant amounts of power.