Spark Photon / Core - Power Shield


I am looking for an out of the box board / shield that can be used as a Li-Po UPS system for the photon / core. Essentially what I require is a board that implements ‘load sharing’ such that the Li-Po battery is not constantly charging / discharging when there is available USB power. Thus, when USB 5V power is available, the photon / core will be powered off that source and the UPS board would maintain the charge level of the Li-Po battery (without constant charge / discharge). When no USB power is available, the photon / core will be powered off the Li-Po battery. Ideally, the UPS board would also be able to signal the photon / core when USB power is lost / regained and when the Li-Po battery reaches low power levels / full charge.

The closest board that I can find is the Adafruit 390, but it is more than what I need (it is actually designed for solar power management) and is currently not in stock anywhere I can find.

Any tips about boards that are currently being used by the community would be greatly appreciated!


A new power shield is currently in the works, and will be released along with the Photon if I’m not mistaken. If you can wait for a bit, then that’s probably the easiest solution, since it should be stackable with the Core/Photon/electron(?).
@mohit can probably tell you more about the options.

I actually have the power shield you are talking about on order already in addition to 5 Photons :slight_smile: The trouble is, I have absolutely no idea what the power shield will actually be able to do / look like. For the life of me, I cannot find any details on this shield let alone any prototype pictures / specs / schematics. Maybe someone from Spark or the community at large can point me to a webpage with these details?

My point being, I am trying to plan ahead just encase Spark decides to make this new power shield as useless and whimsical as the first “mustache” fiasco. (Not trying to knock on Spark because everything else that they have done has been fantastic!)

Trust me, it won’t be a mustachio. Furthermore, it should be the same footprint as the Core/Photon, and it’s likely to be stackable. For more info, it’s best if we wait for @mohit to comment.

there is a tiny bit of info in the more details section of the store. it says its based on the MCP73871.

Thanks for that. Based on that chip’s specs, it looks like the spark power shield might just do exactly what I need… Provided of course that Spark actually implements all of the chip’s features.

1 Like

@Hootie81, based on what I’ve seen in the (hidden) repos, the board will use the TI BQ24030 along with an I2C voltage monitor. It is designed as a shield which can fit under the Core/Photon/Electron (ie, they can piggyback onto it). :smiley:

1 Like

Ah OK I’ll have to do some research on that one now!

Should the store info be changed to reflect this?

Can we please get some prototype design/images of the new power board? I didn’t order one because with out knowing more details it was too risky

@semaja2, we are waiting for Spark to announce/release the final design. I will poke @mohit and @zach to see if we can push this along. :smiley:

Well that TI chip also does pretty much everything I need so prospects seem good that Spark will be making a power board that does exactly what I need. Thanks for all the input guys, but we definitely need some direct feedback from Spark.

1 Like

Hi Guys, I’m just in the process of cleaning up the repo and publishing the design files shortly. There is so much new stuff happening at Spark!

Here is a quick summary of the power shield:

  1. The PCB is of the same footprint as the Core/Photon and is stackable
  2. The heart of the shield is based around TI’s BQ24030 battery management controller
  3. The shield accepts two types of sources to charge the battery and power the Photon simultaneously:
    a. USB port - charge rate limited to 500mA
    b. A DC source from 7V to 20VDC - charge rate set to 1Amp
    (When powered by both, the priority is given to the DC source over USB)
  4. The shield also has an onboard I2C based battery fuel gauge (MAX1704X)

Hope this helps!


Thanks a bunch for the update! That’s exactly and I do mean EXACTLY, what I wanted to see from Spark. Keep up the awesome work!


ooh this is pretty exciting. nice.

Just got my power shield today and I’m generally pleased.

I would like to know what the different colors on the LEDs mean and also to know how to read the MAX1704X from my photon.

Sadly this documentation seems to be MIA so far.

Really pleased to receive my Photons + new power shields today - but I’m also looking for some pointers to documentation.
At the moment I’m not sure what the orientation of the board is, perhaps I’m overlooking something on the board’s print - but I can’t figure out whether my photon’s / core’s USB port should be on the side of the battery connector or not… @owendelong - do you have any idea about that perhaps?

Would this help?

With some heavy-duty searching, I finally managed to find it. In the docs. After about 10 seconds :stuck_out_tongue_winking_eye:


Moors7 beat me to it, but yeah, that’s how it goes. (which is why I hadn’t asked that particular question, I had that already from reading the docs).

However, the questions I did ask remain unanswered at this time and I suppose I might have to find the schematics on GITHUB and look there for my answers, but one would hope that these simple questions could be added to the data sheet.

Okay, I somehow managed to miss that section :cold_sweat: - thanks.

1 Like

Yes, could someone add to the data sheet how to read the power status from the Power Shield. Thanks!

1 Like