FriendlyELEC-Forum

Dear FATech Support
I have a question , about lithium battery pads near SD card socket in M2 board. Is it possible to connect 3.7V lithium battery to it?
Your schematic approves there should be no problem. maybe some changes in U-Boot needed to reconfigure the PMU chip.
Normally it should have 4.2V when power up between +BAT and GND pads but zero voltage measured.

Thank you.

Hello,
It is possible to connect 3.7V lithium battery．But how did you get the zero voltage，is BAT+ to GND? The RTC is battery input, if there is no battery if not charged.

jjm wrote:
Hello,
It is possible to connect 3.7V lithium battery．But how did you get the zero voltage，is BAT+ to GND? The RTC is battery input, if there is no battery if not charged.

hi
I do not mean RTC battery . there is 2 pads near SD socket that should be in relation with PMIC AXP228 chip.
How can I connect battery to it and change the kernel to work with it ?

Thank you.

meisam wrote:
Dear FATech Support
I have a question , about lithium battery pads near SD card socket in M2 board. Is it possible to connect 3.7V lithium battery to it?
Your schematic approves there should be no problem. maybe some changes in U-Boot needed to reconfigure the PMU chip.
Normally it should have 4.2V when power up between +BAT and GND pads but zero voltage measured.

Thank you.

I am testing these pads whit 3.7 li-ion when pressing the power button only one second leds on then goes off
I think need some changes kernel

severel times I am asking to friendly arm for these pads but I am not receive clearly answers for tihs
why I dont know

ekrem wrote:

I am testing these pads whit 3.7 li-ion when pressing the power button only one second leds on then goes off
I think need some changes kernel

severel times I am asking to friendly arm for these pads but I am not receive clearly answers for tihs
why I dont know

Yes , kernel should be updated. in the power option / AXP22x section , you can select battery charging.
I have not check it since i can not not rely on experience.

I`m also wondering why there is such a weak support for these boards , for example I have 2 question for RTL8723BU
WLAN driver problem and GPS pps-gpio pin definition . but no answer received yet.