Message ID | cover.1677620677.git.jahau@rocketmail.com (mailing list archive) |
---|---|
Headers | show |
Series | Add RT5033 charger device driver | expand |
Hi! > Some comments on the end-of-charge behavior. The rt5033 chip offers three > options. In the Android driver, a forth option was implemented. Hmm. I'm working on that on motorola-cpcap driver, and I guess this is going to be common problem for many drivers. > - By default, the rt5033 chip charges indefinitely. The current goes down but > there is always a charge voltage to the battery, which might not be too good > for the battery lifetime. > - There is the possibility to enable a fast charge timer. The timer can be > set to 4, 6, 8... 16 hours. After that time has elapsed, charging stops > and the battery gets discharged. This option with a timer of 4 hours was > chosen by Beomho Seo in the patchset of March 2015. However, that option > is confusing to the user. It doesn't initiate a re-charge cycle. So when > keeping plugged in the device over night, I find it discharging on the > next morning. > - The third option of the rt5033 chip is enabling charging termination. This > also enables a re-charge cycle. When the charging current sinks below the > end-of-charge current, the chip stops charging. The sysfs state changes to > "not charging". When the voltage gets 0.1 V below the end-of-charge constant > voltage, re-charging starts. Then again, when charging current sinks below > the end-of-charge current, the chip stops charging. And so on, going up and > down in re-charge cycles. In case the power consumption is high (e.g. tuning > on the display of the mobile device), the current goes into an equilibrium. > The downside of this charging termination option: When reaching the end-of- > charge current, the capacity might not have reached 100 % yet. The capacity > to reach probably depends on power consumption and battery wear. On my mobile > device, capacity reaches 98 %, drops to 96 % until re-charging kicks in, > climbs to 98 %, drops to 96 %, and so on. Not reaching 100 % is a bit > confusing to the user, too. Is the system powered from the battery in the not-charging case? Anyway, we should teach userspace that "full battery" does not neccessary mean 100%, as keeping battery at 4.3V wears it down quickly. Best regards, Pavel
Hi Pavel, On 25.03.23 17:08, Pavel Machek wrote: > Hi! ... >> - The third option of the rt5033 chip is enabling charging termination. This >> also enables a re-charge cycle. When the charging current sinks below the >> end-of-charge current, the chip stops charging. The sysfs state changes to >> "not charging". When the voltage gets 0.1 V below the end-of-charge constant >> voltage, re-charging starts. Then again, when charging current sinks below >> the end-of-charge current, the chip stops charging. And so on, going up and >> down in re-charge cycles. In case the power consumption is high (e.g. tuning >> on the display of the mobile device), the current goes into an equilibrium. >> The downside of this charging termination option: When reaching the end-of- >> charge current, the capacity might not have reached 100 % yet. The capacity >> to reach probably depends on power consumption and battery wear. On my mobile >> device, capacity reaches 98 %, drops to 96 % until re-charging kicks in, >> climbs to 98 %, drops to 96 %, and so on. Not reaching 100 % is a bit >> confusing to the user, too. > > Is the system powered from the battery in the not-charging case? Yes, at RT5033 in the "not charging" state the system draws the power from the battery. ... Kind regards, Jakob