[Huawei P9 Lite] "Your phone is empty. it will shutdown in 30 seconds"

[littlebigman]

Hello,

I went for a bike ride today, with the battery about 75% full on my ~ one-year old Huawei P9 Lite running Nougat 7.0.

I had been running the Maps.me map application for about 10mns with the screen on, when the phone said it was empty and would shut down within 30 seconds.

At that point, I could no longer start it and follow the route I had planned. Thankfully, it wasn't a long ride and could get home on my own.

That issue already happened a few times while travelling, and plugging an external battery saved my bacon.

Could it be due to Maps.me crunching the CPU too much, and pulling too much power from the battery, causing its voltage to drop too much?

FWIW, here's the infos returned by the MyPhoneExplorer application while the phone is plugged into my Windows computer through USB.

https://postimg.cc/HVFNRXky

Thank you.

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Edit: I couldn't find how to add a reply, so edited the original question.

ukbat >or what it's worth, the picture doesn't really tell us anything relevant to the problem (unless I missed something.

To show the voltage, in case it was relevant (isn't USB 5V?)

> I suspect, though, that you normally run the battery down until it's almost empty every time (or usually),

No I don't, but I do have the habit of plugging the phone into my computer to 1) make sure it's full when I leave and 2) to sync with Outlook through MyPhoneExplorer over USB.

From now on, I'll just make it a habit to bring an external battery + USB cable with me when I intend to follow a route, in case the phone acts up again.

Thank you.

 

[Rukbat]

For what it's worth, the picture doesn't really tell us anything relevant to the problem (unless I missed something).

I suspect, though, that you normally run the battery down until it's almost empty every time (or usually), That will kill a perfectly good, new, battery in a month or two. Lithium batteries of the type used in cellphones are not deep-discharge batteries. The best power cycle is to charge to 80%, then start charging again when the battery drops to 40%. That will give you the longest life.

(Then, why, you ask, do they use lithium batteries? Why don't they use something that can take a deep discharge? There is a battery you can discharge to flat, then charge, then discharge to flat, over and over - it's called a deep-discharge gel cell. The electrodes are lead, the electrolyte is gelled sulfuric acid [also heavy] and the power per unit volume is nowhere near as high as a lithium battery, so you'd need a 5 pound battery that would be larger than a 20,000mAh external battery - in other words, larger than the phone. Lithium is the lightest metal [aside from hydrogen, which is still liquid at absolute zero], and a lithium polymer battery can be made very thin. People want light thin phones, so we have lithium polymer batteries. Given all the facts, the public at large would probably be clamoring for some battery technology that was light, thin and could be discharged to zero - but the phone manufacturers don't give us all the facts [because they can charge you $60 to replace a battery that costs them a few bucks - it's a high-profit job].)