Photon + Power Shield + 7,4V LiPo

Hardware
1

I’d like to power my Photon with a 7,4V 2 Cell LiPo I have. (I need the voltage to power 4 DC motors aswell.)

I was thinking of connecting it through a 5V step down directly to VIN but read that doing so might damage the Photon.
Should I consider getting the power shield? Will I be able to just connect the LiPo into the 7-20V DC input and be done with it?

2

I think the most efficient way to do this would be with a buck convertor directly to 3.3V. This is one example, but there are many, many more.

1 Like
3

Here is another 3.3v buck regulator good up to 1 amp:

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4

I'm not sure what you were reading, but if you are refering to a not yet solved issue where a Photon could lose its mind after a low power condition, you need to take things in your own hands in any case - not matter what shield or converter you use - when powering off a battery to prevent too-low power situations till the actual cause of the trouble is found and fixed.

1 Like
5

Thanks for the info. I don’t know anymore where I read about the LiPo damaging the Photon and it could be that I misunderstood it.

I tried connecting the 7,4V LiPo throug a 5V step down (https://www.pololu.com/product/2098) I still had without any luck getting the Photon to turn on, assuming it would since Vin accepts 3.6 to 5.5VDC.

I am receiving the power shield so I might not be needing to buy a buck regulator at all then. The datasheet of the shield doesn’t say much about it so I’ll assume that it’ll work if I connect the LiPo to the External 7 to 20V DC input?

6

Have you had a look at the hardware repo for the shield?

https://github.com/spark/shields/blob/master/photon-shields/PDFs/Schematics/power-shield-v210.pdf

7

No. Forgot to look in github… there should be a big read button in the particle docs refering to it.

Thanks, I’ll read up on it.