MKRFOX1200 autonomy on batteries

Hello guys,

I've recently bought a MKRFOX1200 from Arduino Store.
On the official website, it says that this board could run up to 6 months with 2x AA or AAA batteries.

So here is my questions : is it possible to power it with a LiPo 3,7v via green screw terminals ? I don't think so because it says "Applying more than 3.3V on any pin will damage the board.". I don't really want to try ! Do you confirm ?

So what are the options to run it for 2 years on batteries ? The project i'm working on is to check the value of a sensor 2 or 3 times per day and immediately go to deep sleep.

Thanks !

astroman35:
I don't think so because it says "Applying more than 3.3V on any pin will damage the board.". I don't really want to try ! Do you confirm ?

Why is any confirmation required?

...R

Because i don't know if this board has a built-in voltage regulator that could handle 3,7v instead of 3v.

A lot of Lipos charge ABOVE 3.7V and quite often nearer 4.7V

Check the charge specs for your battery BEFORE yo connect it to ANYTHING.

Ok thanks for yours answers.
Now, what are my options if i want to run it for 2 years ?

I don't own a fox but regular MKR's.

However power issues have been mentioned in both the actual MKR section so you may well find some useful info in there.

My suggestion and thats all it is would be to use some form of regulator to ensure you don't exceed the required voltage. That said you could also check the technical specs for the FOX to see if it will allow a little more voltage on a particular pin and maybe use that ?

You could also explore using SOLAR to keep a battery topped up.

Options to power almost all the Arduinos are limitless and that would be up to you to choose something specific for your application of the fox.

Your other methods are down to putting the fox to sleep in your sketch to further reduce consumption which is again mentioned in the other MKR sections.

Ok thanks for your answers. I'll search the MKR section to find relevant informations about power issues and check voltage regulators.

I've already manage to put the FOX to sleep in my sketch between two sensor checks thanks to the ArdunoLowPower library.

The specs say USB/VIN is 5Volts

Then a LIPO at 4.7 fully charged would probably be just fine using VIN.

AFAIK it runs via the regulator on the MKR1000 so you would have to monitor performance once it gets to the 3.3V range.

Thanks Mark.

From the Arduino MkrFox1200's specification, it seems that you could apply only 3 Volt on the green screw input. In this case, the internal led remain OFF and also using a lowpower library the consumption of the board is around 700 uA. That mean with a commercial AA or AAA battery the life won't more 2 months (doing nothings !! and not 6 months). If you apply the power from USB or Vin the internal led remain ON and the consumption increase.

For this reason, the initial question of @astroman35 was correct and, sorry but I don't understand the above answers

I'm using 2 Alkalike 4.5 V batteries connected in series, so I have 9V output to power up my sensors and MKRFox 1200. I'm using LM7805C to regulate voltage to 5V for VIN.
In documentation page of MKRFox1200, it's written that you can apply between 5 to 6 v to VIN.

Vin: This pin can be used to power the board with a regulated 5V source. If the power is fed through this pin, the USB power source is disconnected. This is the only way you can supply 5v (range is 5V to maximum 6V) to the board not using USB. This pin is an INPUT.

I’m feeding my MkrFox1200 a 3.7V Lipo, works fine

If 2xAA batteries "theorically" last 6 months, according to this table:
http://www.allaboutbatteries.com/Energy-tables.html
2xC batteries should last close to 4 times that (2 years) and 2xD batteries should last 8 times that (4 years).
Im using the line that assumes we're talking about long life alkaline batteries (cause I guess we can assume that the sigfox 6 month calculation was done under 2xAA Alkaline batteries)

I know C and D batteries are not so common nowadays but they are still sold and if all you need is them to last longer, why not switchting to them instead of using regulators?

pietervannuffel:
I'm feeding my MkrFox1200 a 3.7V Lipo, works fine

Can you please confirm that it still works fine? A fully charged single LiPO cell will provide 4.2V, is this still fine with your board? I totally need to find a rechargeable solution for a MKRFOX, and then apply a solar panel to charge it

Thanks

Still running fine. I use this battery.

edugimeno:
Can you please confirm that it still works fine? A fully charged single LiPO cell will provide 4.2V, is this still fine with your board? I totally need to find a rechargeable solution for a MKRFOX, and then apply a solar panel to charge it

Thanks

pietervannuffel:
Still running fine. I use this battery.

Good to know Pieter...And do you recharge it with a solar panel or anything or just charge it one time and let it work until it's depleted? In case you are charging it (solar panel or whatever) can you provide any details? Thanks!!

Karma for the follow up Pieter.

pietervannuffel:
Still running fine. I use this battery.

How did you connected it, on provided battery input pins or VIN? With some kind of voltage regulation or direct? And do you recharge them while MKR is working?

I ordered today Panasonic 3.7V 3400mAh Lithium Ion Rechargeable Unprotected Battery:
https://www.amazon.de

with some power shield / holder with protection and regulated outputs:
https://www.amazon.de

Hello,
I use a ht7333 regulator with two 1000uF and two ceramic caps.
A small solar panel connected to a tp4056 is loading a single 18650 lition cell.
Starting the device with loaded caps is better.
Soldered is better then on breadboard
It works good and for now it runs for test since 10 days without solar panel.

Andonoc:
Hello,
I use a ht7333 regulator with two 1000uF and two ceramic caps.
A small solar panel connected to a tp4056 is loading a single 18650 lition cell.

Andonoc, from what ather were saying above, it seems that the lithium battery can be connected directly to VBat plug, with no issues. Where are you using the regulator? Can you share an schematic?

Thanks