Here the same problemes from time to time with my battery with Cherry 1.6 (which brought already an improvment to 1.3) at my FP1. Some details here:
I think there exits two “modes” in which the phone/battery accidentally can go in (most likely software related):
- the correct one showing good agreement of percentage/voltage of battery level (= “Battery-mode 1”)
- and another one, where there is a big offset of displayed/recognized level to the real level by about 10-15% (or even more), therefore the level often drops from 15%–>0% in minutes! (= “Battery-mode 2”)
Here my observation from yesterday evening to maybe get some more light into this:
- The last time my FP1 was plugged to charger was unfortunately already in "mode2" (thus battery level is estimated too high)
- Yesterday I went down from 25% down to 0% within some hours, the last 15%–>0% within minutes
FP1 switched OFF itself because the battery was drained out completely
- I plugged into the charger but did NOT switched on the phone (only the loading screen appeared)
- phone loaded from 0%–> ~40% (during switched off)
- next day I continued the loading from 40%–>50% (phone still switched off)
- Then the following (all with charger is plugged-in):
1.) Loading screen showed 50%
2.) I switched ON the phone, while loader is still plugged in
3.) After phone was ready booted, battery jumped to 84% !!
4.) for testing purpose I immediately switched OFF phone again (loader plugged in)
5.) Loading screen showed then still 84%
I am sure that:
- …for this discharging cycle I will again stay at “mode2” and will run into the “15–>0% at 5min” problem again
- …if I will charge the next time while the phone is switched-off in one run up to 70-100% (I think there is a “magic limit” between 50-100%, but I don’t know where exactly), I will enter and stay in “mode1” and everything is fine down to 1% for this cycle !!
So in a bottom line:
Switching off and on the phone with a critical battery status (<50%? <20%?) can trigger it to go to the wrong battery “mode2”, from where it will only gets out by draining out the battery completely & charge in on run above 70-80%.
Same text I send as a ticket to support.