FP2 battery saving challenge

A post was merged into an existing topic: FP2 Battery Problems (drains quickly, gets hot)

I guess I’m lucky to have a well-functioning battery. I’m quite satisfied with it. Yesterday at 10:00 (23 1/2 hours ago) I unplugged the phone from charging during the night (which, as I’ve read above, is not to be recommended) at 100%. One full day later, it’s 9:30 now, the battery is at 71% and 2 days left, according to the estimate. 12% of battery usage is gone due to Wifi, so what I did now is turn Wifi as well as mobile connection off to save power. Too bad it can’t be done with one click (flight mode turns off receiving phone calls as well). So when I’m outside and want to use the internet, I’ll turn mobile on, when I’m at home and want to use the internet (but why would I at home? just for updates) I’ll turn Wifi on.

Usage yesterday:

  • Wifi at home/3G when outside was active.
  • I played some pink noise to improve the sound (inspelen/einspielen of the audio),
  • listened to mp3’s for half an hour or so
  • I checked my email twice while I was outside.
  • that’s all as far as I can remember.

*edit: would love to show a screenshot of 71% after 24 hours and 2 days to go, but how do I make a screenshot?

Just found out how to make a screenshot:

Continuing the discussion from How to make a screenshot with FP2:

Here it is:

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Wow, I am impressed. But then you didn’t use your screen nearly at all? It seems that the screen is consuming a lot of battery, even when put on lowest… I got a thought about if this could be due to the flickering? And that the screen when put on lowest may drain more battery than if put on, let say half, when the flickering is gone? Just a thought…

I guess for some 15-20 minutes yesterday. That’s more than what the average usage of mine will be I guess. I use my mobile phone number to be reachable in case of emergency, call in emergencies and call people who only have a mobile number. I will use the Fairphone just as I did my mp3-player to listen to music on the road (when walking or in public transport, listening to music is too dangerous on a bike). Now that I have a smarthphone, I can look up information like the bus travel times when I’m walking or consult an offline map (Maps.me), search for information and I can now make use of the QR codes in museums that give extra information on the exhibits. I don’t see any other use for it. 15-20 minutes a day is more than the average that will be I guess, once I don’t spend time trying things out.

I don’t usually check for email on my phone, I do that at ease behind my desktop. And for my ease of mind, I don’t use any social media (well, then call YouTube a social medium in panel tests, but I only use that account to bookmark favourite video’s). So I don’t know why people spend so many time looking at their phones, but I can’t imagine myself doing it much.

*edit: 530 euro is a lot of money for so little use, I realize. It’s spend by me mostly to make a statement we as a consumer are willing to buy fair and sustainable electronics, if only they will be produced. My main dream is when in the future I can buy a motherboard, graphics card, SDD’s etc. for my desktop that are mined and produced sustainably and fairly (screen active for my desktop is nearly 50 times the time my phone’s screen is active I guess, some 10 hours a day).

update: 4% of the battery got used the last 8 hours. Wifi and mobile connection off, 2 short phone calls, no other usage (3% power got added by plugging in my phone to upload the screenshot, bringing it back to 67% ()):

(*): which of course begs the question: how do I avoid cheating? As soon as I connect my phone to my desktop to upload a screenshot image, the battery gets a boost, bam, rising from 64 to 67% full. Sorry :hushed: (If you look closely at the image, you can spot the 2 tiny bumps at the time I uploaded an image to create a post in this topic :relaxed: )


Don’t worry…since I guess there is no jackpot for a price, it doesn’t matter.
I think I will have a quite similar average usage than you and like that it is obviously possible to rech at least some days with moderate usage, as I am are used to with the FP1 (4-5 days).
So lets see, I just starting in the next days with it.
@vincent, I would like to follow your battery usage progress, please upload some more screenshots in the next days…if you want. It is a nice comparison witht the “heavy load users” “complaining” about 8h usage :slight_smile:

I will. See you later.

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I’ve been travelling and so my new phone has had fairly heavy use. The battery has lasted reasonably well, surviving whole days of trains/meetings/navigating in unfamiliar places, although I have to manually do things I would have had automatic tools for on FP1. For instance, JuiceDefender did a great job on FP1 of extending battery life whilst still pulling down email etc every 5-15 minutes, so I’d still get alerts for twitter DMs and other things I needed. In FP2, juice defender no longer works (AOSP fail) and so i’ve tried the built in android battery saver, which seems pretty good at saving power but means I have to keep unlocking and using the phone to check things. (or I turn off battery saver and make sure I manually turn off wifi/data/bt whenever possible, which is more effort than i’d like!).


25 hours of having used the phone for just a single phonecall and nothing else, Wifi and mobile data turned off

25% drop (from 67 to 42)

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Doesn’t seem like Wifi was turned off


So that’s why I saw a big drop! I wonder if I did use it last night and forgot to shut it off or does the phone or some app turn it on on it’s own? Have to look more closely at that.

My submission for the challenge: from 100% to 20% in 3 days and 8 hours.

With the advice in mind to keep the battery between 20 and 80%, I’m gonna charge it now.

Usage of today: all data connections are still off, I used my FP2 as an mp3-player for half an hour and made a phone call (3 actually, but 2 weren’t answered).


Hey LaurieJ, and why is that? I loved JuiceDefender on the FP1. Why doesn’t it work? And is there no alternative that does the same job?

Hi Hennu, I think it’s something about more recent Android versions not supporting the same operating system hooks, rather than a fairphone specific thing, but I’m not sure. There’s quite a few threads on various forums about juicedefender + lollipop suggesting it is a common issue, but i’ve not delved into it in detail. Try searching for “juice defender lollipop” for more.


since I switched back to my FP1U and do not use my FP2 in a regular basis, I could extend my battery duration:


  • no SIM cards
  • screen brightness: auto
  • Wifi only active when needed
  • Wifi only 2.4GHz
  • activities: Internet browsing
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Ehrm …
unplugged 15 hrs ago. I … kind of … doubt what I see but well, the next days will show ^^

One SIM, 2G, no Wlan, no Bluetooth, no mobile Data (I use them only on demand). SIM-Card however works, just tested and called myself with another phone. Deactivated serveral apps (youtube, chrome, google maps … ).
I fear there will be a rapid drop somewhen and my battery is not calibrated correctly, but I am curious enough to test it - i wont use my fairphone the next days and will only check the battery stats now and then …

3 days passed. 82% left, estimated remaining time: 12 days.
What sorcery is this? xD


2 posts were merged into an existing topic: FP2 Battery Problems (drains quickly, CPU gets hot)

Here you see the result of my best values achieved in my “real life usage”.
It is with a very low overall usage and a high percentage of stand-by time - and I am still far from happy with this:

Some numbers of the Android Battery screen:

  • WLAN: 2d3h = 32%
  • Stand-by: 3d19h = 23%
  • Display: 2h19 = 17%
  • Calls: 1h20 = 6%
  • Provider/SIM-Stand-by: 3d21 = 5%
  • Android System (active CPU): 1h30 = 2%
  • Android OS (CPU): 1h7 = 1%

I am using “conservative” as CPU governor for ALL (!) cores, and have CPU frequency always limited to 1GHz (instead of 2.5GHz) and never used the display with full brightness.

The havey drops in the curve are either some surfing (10min?!) or doing a call (5-15min?).
All-in-all a usage of about 2h19 with activated display and 1h20 doing calls not achieving 4d duration althoug I really used the total battery capacity (98%) is not very satisfied.
With my FP1 I could EASILY do the same and only go from ~ 90–>20=70% battery!

So there is massive room for improvment, althoug I not really know, HOW?!

If I calculate overall consumption: 98% / 3d20h = 1%/h
During the night I normally have 0.4-0.5%/h with 2 activated SIMs (FP1 had 0.1%/h).

I will continue to work on it - any suggestions how to improve?


A post was merged into an existing topic: FP2: Research on power consumption in IDLE and STAND-BY to prolong battery duration

I … give up. 7 Days passed, 56% left xD
I want to use my FP2 now and the battery shows astounding stamina

Total estimated battery time:

16 days.

Statistics show no relevant jumps, thus I think the estimation is reliable.
This is … impressive I think, although only used as passive mobilephone (“being in my pocket waiting for call”). Of course the time will be way shorter when using wlan, mobile data etc, its ok for me to charge it every or every second day in this case. But I need a phone that is usable after a weekend forgetting it in my backpack while still being able to recieve a call in this time. It seems I got a phone that I still can use after forgetting it for whole 2 weeks. Nice one.