Cubietruck : battery issues

[ccapublic]

Hi All,

 

I did my best to sort the following issues out by searching the web / forum with no success. Please forgive me in advance if topic was already covered.

 

I have a cubietruck running mainline kernel and have installed a LiPo battery.

 

I can get info about the battery by catting  /sys/class/power_supply/axp20x-battery contents. However, some things are weird ;

- capacity reports 0 (but bat is charged)

- voltage_now reports 4.5V (abnormal for a LiPo) while voltage_max says 4.2V (which is normal)

- status says discharging even when on mains

- ssh motd does not show battery status (btw 30-armbian-sysinfo seems to point non existing folders both for mainline_dir and legacy_dir).

 

Any comment whether this is normal or not and if not how to fix it ?

 

Thanks a lot for your support 

 

Cyril

[ccapublic]

Some more info :

 

    - Running kernel 4.14.70-sunxi

    - LiPo battery voltage measured with a multimeter is 4.5V-4.8V depending on load. There is *really* a problem here

 

 

[chrisf]

If I were you I'd measure the battery with a multimeter. If it really is above 4.2v it is a fire risk.

If the board has calibration issues, that's not so bad.

[ccapublic]

Hi. That's what I did and battery has really a too high voltage. So it's either a pmu hw issue (I doubt it) or os/sw issue, but I don't know where to start to try to fix it

 

Do you really think the risk is real here ?

Thanks 

[chrisf]

The risk of fire for unprotected cells is tall of you over charge them. 

They catch on fire when there is an internal short circuit. Over charging is one way to break down the insulation inside.

[ccapublic]

Thanks chrisf. I Will disconnect the battery ASAP.

 

Do you know where this problem can come from ? Configuration ? (Sorry I'm a beginner with armbian & linux in general)

[ccapublic]

Ended up installing i2c-tools and dumping axp209 registers. PMU setup/status as reported by driver match i2c registers... There must be something wrong with the HW as my LiPo IS 4.5-4.8V in spite of correct config... Confused me...