Battery life expectations

I have acer spin 5.
Manufacturer says that it can last around 20 hours.

I’m aware that this estimation is for Windows in some kind of laboratory scenario but in my case I can get maybe 4 or 5 hours (YouTube, some web browsing, nothing too heavy)

Currently I use gnome. The same was in KDE.
I didn’t try Windows because the first thing I did was linux installation.

I tried power-profiles-deamon and TLP.
More or less the same.

Is this normal?

I always wondered how they yield such remarkable results with their testing and benchmarks.

The specifications rate it as a 4-cell 56 WHr battery. To get 20 hours of runtime, that means the laptop is only pulling 2.8 watts for those entire 20 hours? Groundbreaking stuff!


Screen brightness will make a large difference in battery life. As does WiFi activity. As does watching HD videos. As does improper heat dissipation (to allow for better passive cooling, in which the battery performs more efficiently).

However, it might also be the “digitizer” for the touchscreen that doesn’t support Linux as well as Windows. :person_shrugging:

2 Likes

Yes it’s normal. No way any laptop will get 20 hours, no matter what os it’s running. You could also try htop and ensure you don’t have any processes unnecessarily consuming lots of cpu. Watch out for too many open browser tabs that also are running background crap.

I’m aware that 20 hours is out of reach.
As I said I didn’t check how Windows perform.
I though that something about 50% of advertised time would be ok.
I have about 25%

Thank you for answers. I’ll try to play a little more with tlp or and powertop.

The math doesn’t make sense. Not sure why they would advertise this.

Even 10 hours is a stretch, but doable.

How bright do you leave your display?

Do you leave the laptop on a soft surface, such as your lap or a pillow or mattress?

Did you actually time it from a fully-charged battery until it died? (The “remaining time” in the tray is only a best guess.)

In KDE, you can view Energy Consumption (just search for “energy” in kicker or whatever launcher you use) which displays power consumption over time. The simple math formula of battery capacity / power consumption = battery life applies.

Manufacturer claims is usually a 1080p local video playback with low brightness (100-150nits?) and low volume (50-60dB), all radios (wifi, bluetooth, etc.) off, LAN (if any) unplugged, keyboard backlight (if any) off, battery saver mode. Basically absolute minimum usage. If you want a better battery estimation, get either Intel Evo or AMD Advantage certified laptops. Their battery life estimates has to cover some real world scenarios so it’s not that misleading. However, in the end it’s still your own usage scenario that talks.

1 Like

In my home, I usually don’t go above 20% of brightness.
Laptop is almost always at hard table.
I didn’t time, but I am pretty confident that the times is around 4-5h max, but… I’ll test it just to be sure :slight_smile:
From time to time I look at the battery indicator, but it is not my primary test for battery longevity.
Currently, I have 95% of battery, and it says that It will work around 5h50min
Today I decided to give a powertop service a chance :slight_smile:

I bought the laptop 11 months ago.
KDE indicator and acpi says that battery capacity is 86%

acpi -bi
Battery 0: Discharging, 94%, 06:54:25 remaining
Battery 0: design capacity 3634 mAh, last full capacity 3150 mAh = 86%

Is 25% degradation in 1 year a normal? Or this number is not very precise?
I would say that the laptop is not on heavy use. I charge it from 3 to 7 times a week. So it is not connected all the time.

That is not 25% degradation but rather (3634-3150)*100/3634 = 13.3% .
It still seems a bit high or one year.
Perhaps your battery indicators need a reset. Do the following:
-recharge to 100% with system off
-use system with charger disconnected until you run the battery down to where it shuts off
-recharge to 100%.

1 Like

My HP laptop’s battery lost 7% capacity in 9 months, just for comparison.

Losing 13% in one year does creep on the concerning end, but also not unusual.

So considering that you lost 13% of the battery’s rated capacity, and all the other factors involved (and the dubious marketing about such a battery powering a laptop for 20 hours straight :roll_eyes:), I think normal usage that yields about 4-6 hours sounds reasonable.

1 Like