What happens in battery saver mode?

[sting7k]

What exactly happens in battery saver mode? I know it turns off notifications, push email, and updating live tiles. But does it do anything else?

I was trying to kill the battery in my Lumia and it kind of seemed like the entire phone was running slower. Does it step down the CPU clock speed at all? Or some how throttle the data connection? It just didn't seem to be performing like normal in battery saver mode.

 

[eric12341]

The OS in general also tries to consume less power so yes the processor speed does slow down a bit but it shouldn't have a significant hit on performance as that would consume more power.

 

[sting7k]

The system itself was OK. But loading apps and stuff there was noticeable hanging and some elements loaded slower. I had a feeling the CPU speed was stepped down.

 

[socialcarpet]

Great topic! I've been playing around with the battery saver mode too and was wondering the same thing. I have the Lumia 900 as well.

I had my phone on energy saver last night and watched 3 episodes of MadMen on Netflix over WiFi and went in/out of the app to send texts and check email and I didn't notice any performance issues or hiccups.

I'll give it another run tonight though.

I know with laptops, if processor cycling or something similar is used to save energy, the system generally responds to load by making resources available as needed.... i.e. if the system cycles down to 400 mhz, to save energy, it doesn't just sit there, if something demands more power, it can vary the clock speed on the fly instantaneously. If it's in an energy-saving mode, usually it just means a more conservative profile is used..

Not sure how that translates to a smartphone though.

Maybe someone with some more detailed empirical knowledge about how the battery saver mode actually works can chime in.

I'd love to know whats really happening so I can decide when/if to use it.

 

[freestaterocker]

AFAIK the processor doesn't slow down, but background processes are ceased, and your email accounts will go to manual sync only.

 

[canesfan625]

AFAIK the processor doesn't slow down, but background processes are ceased, and your email accounts will go to manual sync only.

Yeah I've never heard of the processor stepping. It probably does that automatically anyway. IE Screen on, off, whatevers

Mostly what happens is your data connection more or less halts. Everything requires you to manually run it.