Power consumption of the photon

I want to use a portable USB power block to power my photon. The power block I have has a capacity of 2200mAh and gives an output of 5V/1000mA. I know the 5V is okay for an output to the photon but I don’t know about the 1000mA part, is that to high? I’m not entirely sure what it means.

I also read that the photon consumes 250mA constantly from another post. If this is the case then how long can the photon run on a power source with the capacity of 2200mAh?

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Hi,

the 1000 mA is what the power block can provide. It does not have to. This is “controlled” by the Photon - it just consumes what it needs. There is only a problem if the power block cannot provide enough current. There is none if it can provide “too much”.

There could theoretically be a problem if the voltage would rise up in case “not enough” current is consumed, but that is not the case for a battery and in any case the voltage regulator of the Photon should be able to deal with a wide range of voltages. So don’t worry!

The how long question sounds like simple math, so it should be slightly less than 9 hours. But in practice it will be less. But this highly depends on the power block and how close to the claims they make they are. So I would say it is certainly less than 9 hours, but how much can only be found by experimentation. Anything between 2 to 7 hours sounds realistic for me. If it is a cheap one then it is probably closer to the 2 hours…

But the question is also if the 250 mA figure is what you want for a battery powered application. I have an application were the photon runs for months with a 400 mA battery. But it is almost always in sleep mode and only wakes up on external events and only enables the WiFI in certain events. Is your application really needing the WiFi and the full processor all the time or can it sleep for times? And I even don’t think that with WiFi it really needs the 250 mA all the time. I would have to double-check that, but I think if you are not actively sending or receiving data it is in practice less.

Hope that helps!

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@garyjamjohnson, @Stevie, the Photon’s typical power consumption with WiFi and Cloud enabled is around 80ma with peaks up to 350ma (ish) when connecting. With WiFi OFF, power goes down to 40ma or less. In sleep mode (STM32 STOP mode), it goes down between 5ma and 10ma. In deep sleep (STM32 STANDBY mode), consumption goes down below 1ma (way below).

The catch with these USB battery packs is they will shut down if current consumption goes very low. So after deep sleep, the Photon can never wake!

This is where the Particle Battery Shield comes in handy. I allows you to charge a LiPo battery and monitor its charge in software so you can get the most out of it. :wink:

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@peekay123, thanks for the details about the power consumption. That mirrors what I was thinking. In the deep sleep I get about 80 uA. Not too great but also not too bad. As I wrote, it runs for months with a 400 mA battery.

The catch with the USB battery pack is an interesting one. But it is not the case with all packs. I have one where it does happen, a second one where it does not happen. The second one is the cheap one :slight_smile: - which also does not have a button to power on…

BTW: For a real long running application I use an Attiny 45 in a deep sleep mode with ~0.1 uA consumption which wakes up periodically and powers the Photon using a Mosfet only when necessary. The limiting factor is the discharge rate of the battery in that case…

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Stevie, I am kinda new to the particle programming, but I have an idea that would like to use this type of code. I would love to use the wifi part of the particle, but I only need it in a project about once a month to report from a single sensor or two. Then, it needs to turn on a pump ( I would probably need a separate 12v battery supply, probably a AA pack, to power a small pump for a few seconds, read a sensor, then go back to sleep for a month. Maybe send me a IFTTT message to say its done its duty and a battery report. Is that possible?

Hi Guys,

I’ve got just the Photon board connected to the power supply. The code running on it is simple LED blink code with just one extra line that turns off the WiFi. At 5V with WiFi off it consumes 48mA. Is this normal behaviour?

Given the data here
https://docs.particle.io/datasheets/wi-fi/photon-datasheet/#recommended-operating-conditions

Plus the current draw of your LED (you don’t tell us more about) I’d say yes :wink:

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I don’t have any LED connected, just onboard D7 LED is blinking. What was confusing for me in that datasheet I couldn’t see whether the current consumption is measured at 5V or at 3.3V. But It seems my guess was correct. Thanks