answered
2014-10-06 22:10:36 +0200
Charging speed depends on a lot of factors. For example one of them is how much power the device is using at the time. So if you see about 1A, it could be the charger is actually outputting 1,5A but 0,5A is used to keep the device running for example. As this varies the whole time it is pretty hard to compare things. So in short the incosistency you see is the charging current fluctuating depending on the power usage of the device. And that can vary a lot depending on the moment when csd reads the value and when it updates it. In effect what you see is the inconsistent power drain of your Jolla ;)
And I almost forgot, the current you can stuff in a battery in a sane way also depends on how much charge it contains, temperature etc... So there is some variation on that side too.
Normally from dedicted charger it should be able to pull the announced power (depending on the quality of the power supply. It's not the first time I have seen a charger only being able to supply barely more than 50% of the announced chargin power). From USB normally it will pull a max of 500mA. If it might have charged seemingly faster that might be due to the battery hysteresis and the low end being a bit more innaccurate. And also if it is a dedicated charging port and the phone manages to recognize it as such it might pull more, but that is a bit hit and miss with most USB hubs as a lot of them do not follow the spec or have a bad implementation.
check the comment that I posted about charging of Li-Ion batteries.
https://together.jolla.com/question/55764/charging-limitation-for-enhanced-battery-life-feature-request/?comment=55979#comment-55979
Any kind of battery is easy to charge back to SOC 80%, but remaining 20% will take more time unless you are able to increase the charging voltage i.e. boost charging. Unfortunately that is seldomly possible with chargers we have available.
What was surprising to me is that avoiding the fullcharge seem to have big impact to the battery lifetime together with full discharge/charge cycles, which has been my operating mode until now.
Hopefully Jolla team will create those configurable charging level alarms for discharging and charging.
perhaps cycle count infirmation would be good for the users as well...
Kari ( 2014-10-06 23:02:08 +0200 )edit