✏ A little Guide to ... Fairphone's Batteries (FP1 & FP2)

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Continuing the “A little Guide to…” series after the GPS Guide
According to @ben 's Poll’s result and the number of posts on the forum another thing a lot of Fairphone users struggle with is the battery.
So again I’m gathering all the tips and solutions for battery related problems that can be found on the forum.
If you need a new battery you’ll get one for the FP2 in the shop, for the FP1 you’ll need to check out alternative battery models ( :warning: These batteries might not be tested for safety and could explode!).
If you need a charger check out the community charger list or get a UK charger from the FP shop.

Problems and Solutions

1. First check if your battery is bloated (esp. FP1)

:warning: If you have any problems with your (FP1) battery, check whether it is bloated. (Perform a spin test to make sure) If so, take it out, don’t use it anymore and dispose of it properly. Here is the official support article.

2. Wrong charging status.

Many Fairphone users experience problems where the battery’s charging level quickly drops and/or stays the same on certain levels. Sometimes this is a precursor for a bloating battery and sometimes the battery’s firmware just has to be reset: follow the #dic:kickstart entry for instructions.

3. Phone discharges quickly (and gets hot)

(See discussions: FP1, FP2)
If this happens to you, first try the battery reset from above. If the problem persists, check if it could be:

  • a defect SD card (like described here)
  • a bad connection (like here).
  • an app that causes a “wakelock” (meaning that the CPU is on 100% all the time and does not go to Deep Sleep. You can use the app 'Better battery stats (Play Store) to diagnose the problem. More info on the procedure can be found here.)
  • this Android 5 bug
  • this Android 6 bug

If neither is the case but you still don’t get through the day with a fully charged battery scroll down for some tips to prolong a battery charging cycle (actually read this whole guide as most issues could present themselves as a draining battery).

4. Battery sits loosely in frame (FP2).

If you sometimes have problems charging your FP2 and experience reboots when your phone is slightly “shocked” (eg when you put it down on the table) then your battery likely doesn’t sit well in the frame.
@BeMiGro first suggested fixing this buy putting paper into the gap(s) and here you can see a visual illustration of the workaround.

5. Charging Problems.

(See discussions: FP1, FP2)
If charging doesn’t work well, take your phone out of your case (if you have one), reboot and try a different/better (more expensive) cable/usb slot/adapter/socket.

If your FP2 battery is completely empty and doesn’t charge see the #emptybattery guide.

  • When charging is a problem, try charging with a datacable. Cheap charging cables have 2 wires, whilst data cables have 4 wires.
  • Use cables with a large wire gauge. OEM cables of large smartphones usually fall in this category. Thinner cables have been confirmed to cause charging misbehavior.
  • If moving/wobbling/touching the cable during charging interrupts the charging process (charging animation toggles between on/off)
    a) check if your USB-Port/Connector of your FP is dirty and clean it carefully with a screw driver
    b) check if the whole USB-Port became loosen, which could indicate a broken soldering point at the motherboard
  • General information for using the original FP1(U) charger (1A, 5V)
    a) While correct charging with the original FP charger it should consume 5.5 Watts while showing the charging animation (check with external power meter)
    b) BUT: the charging animation is also running, when the charger only consumes 2 or even 0.4 Watts or less (e.g. due to bad electrical contacts)
    c) thus be aware, that charging overnight not necessarily mean a full battery, if you are suffering form contact problems like this!
  • Try setting USB debugging to “on” in the “Developer options” screen if charging behavior becomes erratic (problem observed on a FP2 with FP open). Cycling through the different USB connection options in the “Developer options” screen also appears to stabilize charging behavior.

6. Overheat Warning.

Some FP1 users experience paradox warnings that their battery is overheated at temperatures around 0°C. If your battery isn’t actually hot, you can simply ignore the message, but keep in mind that a cold battery will be used faster, also, try to re-heat a bit your battery before charging (simply let the phone go back to a “normal” temperature before plugging it).

Maintenance Tips

  • According to this article as shared by @drcyber it’s best to keep charging levels between 40% and 80% whenever possible (albeit without explaining why). Full charges from 0% to 100% are supposedly not good for your battery.
    The app Battery Charge Limit can help with that.
  • Don’t store your phone fully discharged for a long time.
  • Try to keep your phone/battery away from extreme temperatures and rapid temperature changes.
  • More tips can be found on Fairphone’s Support Article.
  • Just for comparison reasons: The original FP1(U) Battery with 2000 mAh should take 2 hours to completely load (0%–>100%) if a charger with 1 Ampere is used (e.g. the original FP charger, it should consume ~5.5 Watts)

How to prolong a single charging cycle

If you plan on spending a prolonged weekend in the wild without having access to electricity to charge your phone these tips might help:

  • Turn the screen background down. A great way to do so on FP1 is by using the Gravity Box Module, which quickly lets you change the background light by sliding over the top of the screen, on FP2 the brightness slider is found in the notification panel anyway.
  • Turn off all connections you don’t need (wifi, 3g, bluetooth, …)
  • According to @BroX the App Greenify helps saving battery.
  • FP2 has a battery saving function (Settings > Battery > More Options (three dots))
  • For more tips check the FP2 battery saving challenge as well as this, and this topic and the official blog post here.

Wrong Myths

  • Darker backgrounds use up less battery. (@ben corrected my mistake here)
  • Keeping a fully charged phone plugged in can damage your battery. (See discussion here)

Some numbers

Power consumption during charging (phone power off, measured with a power meter):
FP1: P=5.5W => 1,1 A if 5V is provided => calculation: 1h50m for a full charge (2000 mAh), ~2h in reality!
FP2: P=7.7W => 1,54 A if 5V is provided => calculation: 1h36m for a full charge (2450 mAh), if linearity is assumed
If we multiply with 80% efficiency of charger/FP-electronic we end up at FP1=0,9A and FP2=1,2A.
Tested with original FP1-charger and cable, which is designed for 1A@5V (=5W)