Powering photon through 3xAAA issues

Question on the Power Shield. Can you power it from the 3.7 Lipo? Or just charge a 3.7 Lipo?
Or it this just intended to provide a battery charger circuit to something ?


“You can power a Particle device with either a USB plug or a DC supply of anywhere from 7 to 20VDC and charge a 3.7V LiPo battery all at the same time.”

I want to power the particle with a 3.7v lipo and be able to charge it!

Simply supply power to the Power shield with USB or DC source, plug in the battery and photon :slight_smile:

Yes, giving freedom from the grid to the Photon is the foremost intention of this shield, charging is a side feature :wink:

I seem to have endless battery problems…

2 - 2032 Coin-cells == 6v -> Light just flashes green then D7 turns on DIM
1 - 3.7v lipo - works great
2 - AAA - 3v, not enough power
1 - 9v too much power…

Shouldn’t the Coin-cells work ?
I’d rather not use the Lipos as I then have to provide a charging solution. Plus all the small lipos are really meant for quadcopters so they all have strange connectors on them, nothing that will fit a wire-board solution.

You don’t get enough current to feed Photon from 2032 or similar coin cells.

And why not 3x AAA or 4x AAA NiMH?

2x 2032 is 6.0V, but the Photon only likes up to 5.5V!
And the current might be an issue to, but the mAh definetly.

Trying for a smaller form factor. 3 AAA is too big…

And 3x AAAA?

dont think i’ve ever seen a AAAA… Would still be 6v (4x1.5)

Scrap that … brainfart :flushed:

I was thinking of AA as AAA and hence AAA as AAAA.

But how about LiTC primaries 1x 1/2 AAA?

More expensive tho’

Or you do go lower in voltage and power via 3V3 pin.
You could revisit the 1x 2032s this way, but the chip timing might get a bit off then, but 3V should be well above brownout threshold.

There actually is an AAAA battery, and some 9V batteries have 6 individual AAAA batteries wired in series inside!


The particle datasheet says:

Power to the Photon is supplied via the on-board USB Micro B connector or directly via the VIN pin. If power is supplied directly to the VIN pin, the voltage should be regulated between 3.6VDC and 5.5VDC. When the Photon is powered via the USB port, VIN will output a voltage of approximately 4.8VDC due to a reverse polarity protection series schottky diode between V+ of USB and VIN. When used as an output, the max load on VIN is 1A.


Parameter Symbol Min Typ Max Unit
Supply Input Voltage VVIN +3.6 +5.5 V
Supply Input Voltage V3V3 +3.0 +3.3 +3.6 V

In another section it says:


Parameter Symbol Min Typ Max Unit
Supply Input Voltage VVIN-MAX +6.5 V

So, I should be able to power it with 6v? It must be an amperage problem…

You might get away with 6V, but due to variances in components and also possible voltage spikes keeping further away from the absolute max voltage is recommended.
You usually find this difference in datasheets - often with max times how long the abs ratings can be tolerated but going over these either way might mean bye bye to your device.

One approach to consider is to use 4xAAA or 4xAA in series with a diode and connected to Vin. The diode achieves two goals:

  1. A drop in voltage to bring the 6V from the for batteries to about 5.5V,
  2. Protection to permit USB powering without damaging non-rechargeable batteries.

As for the battery capacity, I suggest reading the article http://www.techlib.com/reference/batteries.html

I can save you the “click”, the AAA has 1200mAH and AA about 2400mAH. You need to consider every option to save energy if you plan to run on these batteries.