How do I use the optional battery on a Feather ?

I have a battery plugged into my board into the "optional" battery slot. And I dont know how it is supposed to work.
I also have a 3.5v supply that is plugged into the pin labeled 3V, located right next to the reset button.
Anyway, I was under the impression that if the power that is connected by the reset button, were gone, the optional battery would take over and begin supplying power to the board.
But it doesn't work that way. When I remove the power into the reset-pin-button, the board dies.

Hence my question. Do I need to do more, other than just have the optional battery plugged in ?

thanks

Is the battery charged up?

There are several flavours of Feather but I assume the core design is the same for all and the drawing shows the battery only charges when powered from the USB (VBUS). Can you power the Feather from USB or VBUS pin instead so the battery will charge.

Riva:
There are several flavours of Feather but I assume the core design is the same for all and the drawing shows the battery only charges when powered from the USB (VBUS). Can you power the Feather from USB or VBUS pin instead so the battery will charge.

I will need to check for that and thanks.
My question though was how do I use the 3.7 V provided by the battery if the other power supplies are not available.
Do I need to use the Bat pin ?

hextejas:
I will need to check for that and thanks.
My question though was how do I use the 3.7 V provided by the battery if the other power supplies are not available.
Do I need to use the Bat pin ?

No, when USB is connected then the board is powered and the battery charged. When no USB power is available then the board is powered from the battery. No need to connect extra wires to the VBAT pin (assuming the battery is connected to the battery connector)

Riva:
No, when USB is connected then the board is powered and the battery charged. When no USB power is available then the board is powered from the battery. No need to connect extra wires to the VBAT pin (assuming the battery is connected to the battery connector)

Riva, I think that you might be mistaken. I have a Feather board with a GPS board powered from it. When I have the battery and the USB cable plugged into the feather, the light on the GPS board blinks. When i remove the USB cable and leave only the 3.7v battery, the GPS board is dead.
I think that there must be something that tells the Feather to get it’s power from the battery rather that the USB cable.
Any ideas ?

Do note that the so called '3.7V' battery, probably being a Lithium one, will have a voltage of 4.1 to 4.2V fully charged and 3.0v when discharged.

hextejas:
Riva, I think that you might be mistaken.

Look at the drawing I linked to in #2 and you will see how USB & battery work.
If the battery is charged and you disconnect the USB then it should keep the Feather powered

Maybe you should post a sketch of how the Feather and modules are wired up and links to the battery and modules.

Consider this solved and I was wrong.
What I discovered was that the board was very picky about the voltage of the battery.
I used my adjustable desktop power supply instead of the battery and the board came to life at about 3.4V.
My in circuit battery read at 3.8V so it should have been good, however, the connector for my in circuit battery was messed up and was not making a good connection to the board.
After I corrected that, the board came to life.
Now I am wondering at the design of this beast. The battery is always connected therefore the board is always alive. Maybe I should figure out a way to put it on a switch.

Thank y’all (<----- Texas talk), for the help.

Glad you got to the bottom of the problem.

The Feather has a battery charge/monitor chip that is designed for a single cell LiPo battery.
To protect the battery it will stop it discharging at about 3.5V and stop charging the battery when its voltage gets to about 4.2V.