Rapid battery loss when phone off

[YellowJersey]

So I've got ancient phone (Blackberry Z30) whose battery is still holding up pretty well despite it's age. I turned it off for some reason the other night and when I woke up, the battery had gone from 96% down to 52%. In contrast, if I leave it on, it usually only dips down from 96% to 87% overnight.

 

 Just curious how turning a phone off would cause such a huge battery loss.

[kelvinhall05]

Turning the phone on/off might use a lot of power for some reason.

[manikyath]

22 minutes ago, kelvinhall05 said:

Turning the phone on/off might use a lot of power for some reason.

may as well be this.

 

maybe the act of shutting down, and then powering it on again demands a certain load the battery cannot efficiently provide anymore.

what happens when you power the device off, and then right back on again? does this have the same effect or is it only a ~5% or so drop?

 

it could also be worn out components messing with power states, actually making the "powered off" power state more energy draining than the "powered on" power state. (fun fact: anything that has a "push to power on" button isnt really off entirely when powered off, because you need brains there to respond to the button.)

[YellowJersey]

1 hour ago, manikyath said:

may as well be this.

 

maybe the act of shutting down, and then powering it on again demands a certain load the battery cannot efficiently provide anymore.

what happens when you power the device off, and then right back on again? does this have the same effect or is it only a ~5% or so drop?

 

it could also be worn out components messing with power states, actually making the "powered off" power state more energy draining than the "powered on" power state. (fun fact: anything that has a "push to power on" button isnt really off entirely when powered off, because you need brains there to respond to the button.)

Interesting. It would make for a good TechQuickie episode.

 

 Thanks!

[manikyath]

Just now, YellowJersey said:

Interesting. It would make for a good TechQuickie episode.

 

 Thanks!

it wouldnt, because literally 3 people care about *why* their phone is starting to show battery issues.

[jmack]

2 hours ago, YellowJersey said:

So I've got ancient phone (Blackberry Z30) whose battery is still holding up pretty well despite it's age. I turned it off for some reason the other night and when I woke up, the battery had gone from 96% down to 52%. In contrast, if I leave it on, it usually only dips down from 96% to 87% overnight.

 

 Just curious how turning a phone off would cause such a huge battery loss.

All batteries suffer from some type of self-discharge, even when not connected to a device. That being said, normally it takes longer than just a day. A new NiMH will completely discharge itself in about 3 months, Li-ion is better though.

That being said, with older devices, I would take the battery percentage with a grain of salt. It's complicated math enough to figure out battery percentage and it's based on expected voltages of the battery and discharge curves. That being said, when a battery gets old the discharge curve is much faster and the voltage the ideal voltage of the battery can not be sustained as long. Even a bad battery, when it finishes charging, it will show 100% even if it's not charged completely. It may be that when you turned your device off and back on the next day, the phone recalculated the real percentage based on the current voltage.

 

If you are daring, here is an Ifixit article to change the battery. 

 

[YellowJersey]

1 hour ago, jmack said:

All batteries suffer from some type of self-discharge, even when not connected to a device. That being said, normally it takes longer than just a day. A new NiMH will completely discharge itself in about 3 months, Li-ion is better though.

That being said, with older devices, I would take the battery percentage with a grain of salt. It's complicated math enough to figure out battery percentage and it's based on expected voltages of the battery and discharge curves. That being said, when a battery gets old the discharge curve is much faster and the voltage the ideal voltage of the battery can not be sustained as long. Even a bad battery, when it finishes charging, it will show 100% even if it's not charged completely. It may be that when you turned your device off and back on the next day, the phone recalculated the real percentage based on the current voltage.

 

If you are daring, here is an Ifixit article to change the battery. 

 

I might just give that a try when this ol' girl finally gives up the ghost. Fortunately, I have a backup by way of a brand new Blackberry Leap waiting to go as a replacement. (it was cheap and I actually prefer the more limited functionality of BB10 since it means I'm not glued to my phone all day and primarily just use it as a phone. To each their own.)