Re: [android-developers] Re: Extreme battery life
On Tue, Nov 22, 2011 at 5:14 PM, Bret Foreman bret.fore...@gmail.com wrote: No, I don't have to take sensor data except right before I launch the daily reading. But even when the CPU is just ticking over doing nothing it still has to keep a bunch of volatile state in registers and RAM and such. All that stuff might add up to over 1 mA. Really deep sleep modes usually store everything volatile into flash and then current drops to under 10 uA - just enough to run a little wake-up counter. But I don't think Android can do anything like that, even if the underlying hardware (like the ATMega) supports it. I was under the impression that the CPU was stopped in Android's sleep mode, but I certainly could be mistaken. The closer you get to hardware, the worse my comprehension. Solar is not an option but outboard batteries might work. Charging through the USB port is not very efficient, though, so I'd lose a lot of the benefit of a big external battery. You could always go with a diesel generator... :-) If you want, give me an idea of what sort of device you'd want to be running, and I can try to find something roughly equivalent here in my Secret Mountain Lair. I'll charge it up, put it on airplane mode, and let it sit for a couple of weeks, and we'll see what the battery level dropped to, with the stock battery. You could run that test too, of course, if you have a spare device lying around. While it wouldn't include the drain from your app, it'd at least give you an idea as to whether or not there's a prayer of it working for four months. -- Mark Murphy (a Commons Guy) http://commonsware.com | http://github.com/commonsguy http://commonsware.com/blog | http://twitter.com/commonsguy _The Busy Coder's Guide to *Advanced* Android Development_ Version 2.1 Available! -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
RE: [android-developers] Re: Extreme battery life
Have you considered a solar phone charger? http://www.rei.com/gear/feature/search/Google/solar%20charger?s_kwcid=TC|130 29|solar%20phone%20charger||S|e|8644334045cm_mmc=ps_google_CH-_-Category%20 -%20Nav%2fCom-_-Nav%2fCom_Solar_Charger_General-_-solar%20phone%20chargergc lid=CMzSxdazy6wCFQLj7QodmB--qA -Original Message- From: android-developers@googlegroups.com [mailto:android-developers@googlegroups.com] On Behalf Of Bret Foreman Sent: Tuesday, November 22, 2011 6:22 PM To: Android Developers Subject: [android-developers] Re: Extreme battery life On Nov 22, 2:52 pm, Mark Murphy mmur...@commonsware.com wrote: If you want, give me an idea of what sort of device you'd want to be running, and I can try to find something roughly equivalent here in my Secret Mountain Lair. I'll charge it up, put it on airplane mode, and let it sit for a couple of weeks, and we'll see what the battery level dropped to, with the stock battery. You could run that test too, of course, if you have a spare device lying around. While it wouldn't include the drain from your app, it'd at least give you an idea as to whether or not there's a prayer of it working for four months. Mark, that would be very nice of you. If it turns out that Android truly stops the CPU then I'm in business...I can shop around for the lowest sleep-mode power model with the fattest extended life battery. If it turns out the CPU is still running in some fashion then I don't think any phone will work. -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Re: Extreme battery life
On Tue, Nov 22, 2011 at 6:21 PM, Bret Foreman bret.fore...@gmail.com wrote: Mark, that would be very nice of you. Contact me off-list and we can figure out what device(s) I'll test for you. -- Mark Murphy (a Commons Guy) http://commonsware.com | http://github.com/commonsguy http://commonsware.com/blog | http://twitter.com/commonsguy _The Busy Coder's Guide to *Advanced* Android Development_ Version 2.1 Available! -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
RE: [android-developers] Re: Extreme battery life
Ah ok well best of luck with your endeavor! -Original Message- From: android-developers@googlegroups.com [mailto:android-developers@googlegroups.com] On Behalf Of Bret Foreman Sent: Tuesday, November 22, 2011 6:47 PM To: Android Developers Subject: [android-developers] Re: Extreme battery life On Nov 22, 3:33 pm, Tommy Hartz droi...@gmail.com wrote: Have you considered a solar phone charger? The environment is too dirty for a solar charger. It doesn't take much dust to cut the panel efficiency down to almost nothing. -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Re: Extreme battery life
On Tue, Nov 22, 2011 at 02:14:30PM -0800, Bret Foreman wrote: Solar is not an option but outboard batteries might work. Charging through the USB port is not very efficient, though, so I'd lose a lot of the benefit of a big external battery. You don't have to *CHARGE* through USB...just power your device with the USB charger. For safety purposes, I suggest avoiding a lead-acid battery. Pick up some large 12 VDC gell cells and put them in parallel. Then connect them to a cigarette lighter USB charger/power supply and use that. Use a good DMM (e.g., a Fluke 77, etc.) and measure the current usage during both modes and the respective times, and do the math for mAH requirements for the gell cell pack. Then determine how many gell cells you need. Make sure they are all healthy and charged at the same level (charging them while connected in parallel should do). HTH. Later, --jim -- THE SCORE: ME: 2 CANCER: 0 73 DE N5IAL (/4)MiSTie #49997 Running FreeBSD 7.0 spooky1...@gmail.com ICBM/Hurricane: 30.44406N 86.59909W Do not look into laser with remaining eye! Android Apps Listing at http://www.jstrack.org/barcodes.html -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
