Battery flat after 3-4 days

[sparkymark]

Hi

I recently full charged my battery leaving it on all night to charge.

I switch it back on today after two days and I am down to 48% battery left. The pandora was definitely switched off correctly. Is this to be expected or have I got a dud battery? This plus shoulder button plus bezel issue makes me wonder whether I should send mine in for an overhaul. I don't want to be picky but I've waited so long I want my pandora perfect. what do you think?

 

[mali]

Did you select shutdown in the menu or did you toggle the power switch?

 

[sparkymark]

Did you select shutdown in the menu or did you toggle the power switch?

unplugged, then shut down properly through the os

 

[mali]

You definitely were at 100% when you shut down? Sounds like a faulty battery to me.

edit:

i took my battery out overnight and when i put it back into my pandora it wouldnt turn on. i plugged in the charger and nothing.
i unplugged and replugged the charger 10 or so times and finally it booted up.

The battery was so discharged that it was too low to turn the system on. Leaving it plugged in and plugging it in and out 10 times just cumulatively added up to enough charge time to exceed the 3.2V threshold the PMIC needs to leave the pre-charge state.

it's now sitting with the charger plugged in and i watched the charge go from 0 to 1%.

This confirms it here which is nice. Being at 0% means you are just out of the pre-charge area.

looks like my battery may be duff?

Let's find out. In some experiments with other projects, I have learned one way to recognize a dead/dying battery. I assume this is accurate as cells shouldn't do this normally. Please try this procedure if you don't mind:
- Charge battery to 100% if you can get it there. Record that maximum percentage you were able to get to if not 100 but get there if possible.
- Shut down and remove battery. If you have a voltmeter, measure the battery's voltage and record it to tell me. The voltage is across the two outer pads on the battery pack as labeled.
- Leave the battery sit at standard room temperature (20-25C, not too humid an environment, etc.) for a 24 hour period. Stick it in the battery box or something so that it is safe and out of the way.
- Run your unit on AC only if that works for your board (being experimental and a 'test' feature as I've mentioned before, it still doesn't work on absolutely all boards for some reason). This way you can still enjoy playing around for that day rather than being Pandora-less unless you are too busy anyway.
- At the end of the 24 hour period, measure the battery voltage with the voltmeter if you have one. Let me know the new voltage. If you don't have a voltmeter, you will have to stick it back in and boot up. Let me know the new percentage. A few percent would be tolerable as cell voltage relaxes after charging completes. Tens of percentage drop would indicate the cell is toast and you should contact OP sales for a new one. A 48 hour period would be even better because it will likely keep dropping and I forget how long I set my intervals when testing some batteries I turned into balloons but it was in the 24-48 hour range. I think one day should give us the data we need.

Are you still on your first battery? I don't think you have a replacement already right?

Thanks.

 

[Pleng]

I loose about 6% over an 8ish hour sleep. At that rate, over 48hours you could expect to loose 36%.

If it was off for more than 48hours, then 50% loss wouldn't be entirely out of the question.

The real question is, how did you manage to leave it alone for 2 days?!!

 

[sparkymark]

hmmmm Pleng, thats not what mweston is saying though. i think i'll give it another charge test and see what happens.

as for leaving it alone i had a busy weekend. am typing from it now though so all is well in the world

 

[tsh]

I've seen some variable power consumption behaviour - probably you are not getting everything sleeping properly for some reason. There is more work to do on low-power, and I don't think what you are seeing is completely unreasonable. For now, powering off seems a good option when not in use (unless you are also charging)

 

[Pleng]

tsh, we're talking about when the Pandora is switched completely off. And sparkymark, I don't care what MWeston is saying, I'm giving you real figures from my actual system which has been consistent for the three weeks I've had it.

 

[tsh]

tsh, we're talking about when the Pandora is switched completely off. And sparkymark, I don't care what MWeston is saying, I'm giving you real figures from my actual system which has been consistent for the three weeks I've had it.

Sorry... i missed that part
Mweston quoted ~10% per day, I think. Sounds pretty poor - i would blame it on temperature, but since the OP is north of me, that seems unlikely. More data needed, both from hourly power up/down (logging bat%, and daily.
p.s.
http://pandorawiki.org/PowerModes

 

[jlepley]

I don't think the battery will lose power at a flat rate, it'll probably follow a line of exponential decay.

 

[marshal]

I very much doubt the battery by itself would lose so much power (unless it's deffective of course)...

Would be interested to test it with battery in and out the device. I would guess it's something about the Pandora that make the battery discharge so fast..

 

[sparkymark]

I'm Sorry, but You don't know what you are talking about. Suspend to RAM is the technology that was used on the Palm devices to give them that "instant on". It's also used on the DS when you close it up. Suspend to RAM is the most useful function a handheld can have, as far as power conservation is concerned, IMHO.

Oh, and this Low power mode we have currently is in the complete opposite direction of what any low power mode we should have using the ARM. For that, we would need probably kernel improvements, which would also most likely enable us to have Suspend to RAM and Suspend to Disk anyway.

-God Ginrai

I can't comment on Palm as I don't own one and I also think older ARM devices were not designed to be always on.
I consider my N800 to be not _that_ old with its OMAP2 and it doesn't have a suspend mode, neither do current smartphones. When you suspend you'd lose too much functionality, imo. A properly optimized low power mode should give a standby time of around two to three weeks and that is enough, imo.

well my battery only lasta about 3-4days switched off so I don't see how I will get a few weeks in low power mode, unless keeping it switched off slows the discharge? (honest question).

 

[mali]

Is the unit shut down via menu? There is a battery troubleshooting mini-FAQ in the Tweaks Thread.

(edit: merged with original topic, thanks for paying attention, tsh )

 

[tsh]

Bumping this thread, since the issue seems not to have been resolved... Should be merged with the other post Mali forked...

Need some good samples of battery discharge rates.
http://pandorawiki.org/TalkowerModes

My data point is unpluged and shutdown overnight (13 hours), was @100%, read 99% when turned back on.

Please add more data points, for any period over 12 hours that you can bear to leave your Pandora off (or in any other interesting state)

 

[mali]

sparkymark, you should request a new battery from Gbax.

 

[jonlad1]

Ok, I completed a couple of interesting tests.

I charged the battery overnight so was 100% at 6:30am. I turned off (as in completely off, logout>shutdown) then at 3:30pm turned it on and was at 81%

I did the same last night, but this morning at the same time, I removed the battery instead of leaving it in. At 3:30pm, turned my Pandy back on and still at 100%. Strange eh?

I have another battery. I will try the same overnight.

 

[Polossatik]

I shutdowned my pandora at 100% charged yesterday (shutdown trough OS) , left it now for about 9 hours (= sleep ) booted it up, left it for a minute or 2 to make sure the gauge is updated, showing "100% 11h56" ...

Edit: this was shutdowned with wifi and BT off - not sure if it make a difference, but might be worth to check

 

[tsh]

To me, it seems that there are 2 scenarios which are seen on shutdown, either 0 power drain, or 10-20% per 24 hours. Maybe the 2nd case is relating to not really shutdown (as has been observed can happen in different ways). I will I think try to add some logging into the power management scripts (unless someone else wants to do it first). This may help to understand when the device is really in which state.

 

[Prometheus]

If I may give some input here that may or may not be relevant: During the very hot weather we got a week or two ago, on the hottest days my Pandora's battery consistently lost a percent or two more than usual overnight. When the weather cooled back down again, the battery discharge returned to its normal one-half to one-percent overnight.

 

[jonlad1]

Well its been pretty cold here at night. Like 0 degrees C. But that would explain why the battery looses less charge whilst being out of the Pandora....