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So it would be interesting display the Voltage. Cheers, Cesar 17.01.2017, 15:52, "Marcin Xc" <gtriderxc@xxxxxxxxx>: > There is one more thing I'd like to add to this discussion that You can see in the picture: > http://ep.com.pl/cache/images/norm/3/1/7/c3JjPS9pbWFnZXMvbm9ybS8zLzEvNy8xMzMxN2FrdW11bGF0b3J5X3J5c18yMC5qcGcmdz05MDAmaD01OTQ=_srcb9bd5f071626572b62658662f22e4c3d.jpg > > The green line "Pojemnosc" is capacity. The red one "Napiecie ogniwa" is voltage. In a healthy Li-Ion battery You can pretty easily display the capacity if You know the voltage. At least till ~~4V. Then You see these magical 99% that need longer. Why they need longer You can see in the picture: when the voltage says 4-4.1V the battery has only 83% of its capacity, in this case. > What is the other case? The other case are different Li-ion Batteries. No of Your batteries is >Li<-ion. They are for example LiFeYPO4 or LiFePo4 also called more correctly LCO, LMO, LMC, NMC, LFP. They have different capacity at their 4-4.1V. If You see on the display that Your battery is 99% full it can mean that it has something about 3,9-4,1V and that means it is only 60-80% full (picture). > > I still wonder why I do not have absolutely ANY problems with my battery (E4.5, OTA14) and the only answer that came to my mind is that perhaps my battery is different than Yours? If any of You would like me to crash test my battery, just write me what I shall do to join the bug report. There are only two things I won't do: I will not let the capacity drop under 20-30% level (I already experienced that this phone doesn't like it) and I will not leave my phone connected to the charger longer than needed when it reaches the 100% level. > > One more thing: between the physical "+/-" battery and the physical phone there are always electronic pieces that tells You the voltage and that are responsible for it. So the real battery (as we can see and touch in a car) stays in a phone/Notebook/mp3player always behind a kind of an overcharging/totally discharging/overheat protecting firewall. If Your phone doesn't stand up it doesn't mean that the battery is under 2V or 1V, zero and empty. It means that the electronic security doesn't allow You to turn it on any more to protect Your battery chemically. > > Best regards > > Marcin > > ---------------------------------------- > From: Selene Scriven <selene.scriven@xxxxxxxxxxxxx> > To: Matthias Apitz <guru@xxxxxxxxxxx>; ubuntu-phone@xxxxxxxxxxxxxxxxxxx > Sent: Monday, January 16, 2017 7:04 PM > Subject: Re: [Ubuntu-phone] Battery statistics and flashing bricks > > * Matthias Apitz <guru@xxxxxxxxxxx> wrote: >> Yes, exactly like this, with meters in addition. > > Although not shown in the picture, I have the phones instrumented > with meters along the path for primary power and USB, and use it > to check power consumption on each new build. > > For example, here is a summary of one type of krillin power usage > for 50 builds during a time when a relevant bug was introduced: > > http://toykeeper.net/tmp/phablet/power/krillin-rc-proposed,en-power_usage_display_on-287-336-smooth.png > > Toward the right side, it spikes for several builds until we had > the bug isolated and fixed. The red columns indicate when it > thinks there is a new bug, and green is when it thinks something > was improved. The blue area is where it expects the result to be > based on recent measurements. So, bug found and fixed. If I > recall correctly, this particular bug was the reason an OTA > release got delayed. > > Then a few builds later, in r335, it noticed an unusually high > variation between individual measurements, and marked that build > for inspection. For context, here is a more detailed graph for > r334, when everything was behaving: > > http://toykeeper.net/tmp/phablet/power/krillin.334.display.png > > The green section is the part of the measurement it "counts" for > the test. Red sections mean USB was plugged in so those values > aren't relevant. In this case, it's just letting the phone idle > with the screen on right after booting. Five measurements, and > they're all pretty consistent. > > Then in the next build it had one measurement which didn't look > quite right: > > http://toykeeper.net/tmp/phablet/power/krillin.335.display.png > > So it marked that build for inspection, with detailed logs > available to help identify what happened. > > This is how we've been detecting and fixing power consumption > bugs, making sure each new OTA is the same or better than the > ones before it. But that's mostly for userspace bits. Kernel > and firmware issues are trickier. > >> hat I do not understand is the issue my wife sees from time to >> time: her device shows 50% or 60% of remaining capacity, for >> longer time (due to nearly no use of the device), and within >> minutes the capacity goes to zero and the BQ E4.5 is a brick in >> her pocket. I understand what you say, Selene, about >> discrepancies in the layers an error in interpreting the >> voltage, but I do no see, how can lead this to 50%-to-0% in a >> few minutes. Have you found something, which explains this? > > Yes. Especially when a device spends a lot of time in standby. > The daemon which generates that percentage estimate can sometimes > go a long time between updates... and when it does update it has > a tendency to lag. > > For example, one day I was testing by manually changing the input > voltage and recording how the phone responded. What I found was > that the kernel's reported voltage lagged behind the actual > voltage when the actual voltage decreased quickly, but it tracked > closely when voltage increased. Additionally, it sometimes took > a while for the reported percent (and built-in charge graph) to > catch up. > > In this graph comparison, the green line is what the power supply > voltage was set to, the blue line is what the kernel reported, > and the rainbow graph is a screenshot of what the phone reports > to its user. After manually dropping the voltage to "almost > empty", it took about 40 minutes for the UI to catch up and it > did the thing where it went suddenly from like 60% to 0%. > > http://toykeeper.net/tmp/phablet/power/battgraphs.png > > Then a bit later (I let it keep measuring), I noticed some other > odd behavior. Although it hadn't noticed earlier that the > voltage went back up, when it finally updated again it changed > the UI's rainbow graph retroactively: > > http://toykeeper.net/tmp/phablet/power/battgraphs.2.png > > After the kernel noticed the increased voltage, the UI took over > an hour to update. > > If it drops suddenly to zero, that usually means the battery > itself has been dropping for quite a while and the capacity > estimation software simply took a long time to catch up. > > The kernel's reported voltage level isn't perfect, but it's a lot > closer to reality than the percent shown in the UI. > > Of course, there are other factors which make it a bit awkward... > like the way battery voltage sags under load then recovers later. > Play an intensive game and the cell voltage might sag to 3.4V... > but turn the game and screen off and voltage may recover to 3.8V > within a couple minutes. So it can be tricky to convert a > measurable trait (voltage) into an un-measurable trait (percent > charge remaining). And the effective capacity isn't a simple > graph from volts to percent; it changes with the discharge load > so it's more of a 3-dimensional graph. And as the cell ages, the > 3D mapping from voltage+amperage to percent changes, so it needs > recalibration once in a while. > > -- Selene > > -- > Mailing list: https://launchpad.net/~ubuntu-phone > Post to : ubuntu-phone@xxxxxxxxxxxxxxxxxxx > Unsubscribe : https://launchpad.net/~ubuntu-phone > More help : https://help.launchpad.net/ListHelp > > ,-- > Mailing list: https://launchpad.net/~ubuntu-phone > Post to : ubuntu-phone@xxxxxxxxxxxxxxxxxxx > Unsubscribe : https://launchpad.net/~ubuntu-phone > More help : https://help.launchpad.net/ListHelp
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