Why the imx28evk does not charge the attached battery when the kernel starts up?

cancel
Showing results for 
Search instead for 
Did you mean: 

Why the imx28evk does not charge the attached battery when the kernel starts up?

296 Views
Contributor II

I am using imx28evk and I have attached to it a battery with the following specs, Li-ion 3.7 1000mAh/3.7Wh,

The sequence of steps are the following:

1) Power down the EVK and attached the Li-Ion battery at the connector J86.

2) Switch the SW1 to Battery

3) Attach the power cable

4) The kernel starts up

5) I check sysfs and I get the following info:

root@imx28evk:~# cat /sys/class/power_supply/battery/uevent
POWER_SUPPLY_NAME=battery
POWER_SUPPLY_STATUS=Not charging
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_HEALTH=Good
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_VOLTAGE_NOW=3896000
POWER_SUPPLY_CURRENT_NOW=0
POWER_SUPPLY_TEMP=39

6) I remove the power cable

7) I check again:

root@imx28evk:~# cat /sys/class/power_supply/battery/uevent
POWER_SUPPLY_NAME=battery
POWER_SUPPLY_STATUS=Discharging
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_HEALTH=Good
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_VOLTAGE_NOW=3864000
POWER_SUPPLY_CURRENT_NOW=0
POWER_SUPPLY_TEMP=41

8) I put back the power cable,

9) Check again :

root@imx28evk:~# cat /sys/class/power_supply/battery/uevent
POWER_SUPPLY_NAME=battery
POWER_SUPPLY_STATUS=Not charging
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_HEALTH=Good
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_VOLTAGE_NOW=3896000
POWER_SUPPLY_CURRENT_NOW=0
POWER_SUPPLY_TEMP=39

I was expecting the battery to get charged when is not in use and when 5V power is available.

Any ideas how to switch to charging mode when the power cable is on? Is there any threshold that needs adjustment for my battery?  

Thank you

A

PS: I use Linux version 2.6.35.3-maintain+yocto+g903363e (pokybuild@ab05.i.yoctoproject.org) (gcc version 4.8.1 (GCC) ) #1 PREEMPT Sat Nov 23 06:35:02 UTC 2013

0 Kudos
1 Reply

55 Views
Contributor II

I think it is not a problem - If the battery is fully charged or nearly fully charged the  BM algorithm wont charge it.

0 Kudos