Hi,
I understand the role of the small battery on the SAM-M8Q breakout.
I am building a board of my own that has a 3.7V LiPo battery. Do I still need this backup battery? Can I tie the backup pin directly to the LiPo battery?
Thanks
Hello daniel.
The maximum allowable voltage on V_BCKP for this particular GPS is 3.6 volts and a LiPo is going to be between 3.7 and 4.2 volts. There is no backup pin on the breakout board, but the on board battery does charge from the 3.3 volt supply. I would recommend against connecting a LiPo to the board as 1- there’s no place to connect it without removing the existing battery, and 2- the board lacks a voltage regulator to handle a LiPo.
Hi there,
Let me clarify. This will be on a custom PCB.
Can I hook up only a 3V3 regulated supply and not use the battery at all?
I don’t think a backup battery is required, but you might check the [data sheet to make sure.](https://cdn.sparkfun.com/assets/4/e/b/9/f/SAM-M8Q_DataSheet__UBX-16012619_.pdf)
Ok, to confirm.
If I am using the development board and I take out the battery but have VIN plugged into a suitable voltage, will the backup option still work?
What development board are you using? [This one?
If you remove the battery from the board but apply 3 volts, the backup function will work as long as power is present. Once power is removed, all memory is lost.](SparkFun GPS Breakout - Chip Antenna, SAM-M8Q (Qwiic) - GPS-15210 - SparkFun Electronics)
Great, I will remove the battery and instead apply a 3V3 regulated voltage