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Topic: Power MKR1000 via 3.7v 18650 battery? (Read 2908 times) previous topic - next topic

cloudfarm

Does anyone have any experience to power MKR1000 via 3.7v 18650 battery (https://www.amazon.com/3000mAh-Rechargeable-Li-Ion-Battery-Charger/dp/B004LHFU62)? It seems that these batteries have higher capacity than the Polymer Lithium Ion Battery. I want to use 3.7v 18650 battery for my project but wonder if I miss some details, such as protection circuit and etc.

ballscrewbob

#1
Sep 14, 2016, 04:50 pm Last Edit: Sep 14, 2016, 04:56 pm by Ballscrewbob
Hi Cloudfarm.

I tried one with 18650's and with a proper lipo.
Neither was much of a success as the MKR seems to lack any proper deep sleep.
Battery life was pretty poor with both type of battery but they do work.

if you could turn off the onboard LED's and the WiFi properly I am sure it would be so much better.

If its for a remote use app then maybe adding solar charging to the batteries would help quite a bit.

There is a bit more info on charging etc HERE and HERE
It may not be the answer you were looking for but its the one I am giving based on either experience, educated guess, google or the fact that you gave nothing to go with in the first place so I used my wonky crystal ball.

sandeepmistry

Quote
if you could turn off the onboard LED's and the WiFi properly I am sure it would be so much better.
There's a pull request open in the WiFi101 library to make "WiFi.end()" completely disable the WiFi module.

https://github.com/arduino-libraries/WiFi101/pull/100

Please try it out, and leave any feedback on Github :)


Also, there are new API's to enable power save modes for the WiFi module in v0.10.0 of the WiFi101 library (they need to be documented in the website reference):
  • WiFi.lowPowerMode()
  • WiFi.maxLowPowerMode()
  • WiFi.noLowPowerMode()


 

ballscrewbob

Thanks Sandeep

Already have 0.10.0 installed but for sure would like to see a LED disable function.

Once again you save the day.
karma duly added to the maestro of the MKR  :)

Starting to build my maker (Arduino) bench tomorrow so will be able to play a little more.
It may not be the answer you were looking for but its the one I am giving based on either experience, educated guess, google or the fact that you gave nothing to go with in the first place so I used my wonky crystal ball.

sandeepmistry

Hi @Ballscrewbob,

Could you please give more details on the LED issue? I don't have Lipo battery to test with unfortunately.

A photo of what you're seeing would be awesome.

ballscrewbob

Hi Sandeep
Its going to be a couple of days or so before I can break out all my Arduino stuff.
Weather is good so catching up on outside jobs before I am allowed to continue putting my benches back up.

She who must be obeyed says so LOL
It may not be the answer you were looking for but its the one I am giving based on either experience, educated guess, google or the fact that you gave nothing to go with in the first place so I used my wonky crystal ball.

sandeepmistry

Hi @Ballscrewbob,

No worries, whenever you have time :) Enjoy the weather!

trewjohn2001

I´d like to tag along with this thread - Adafruit have a charger that it says can be used on both Lithium ION and LIPO - https://www.adafruit.com/products/1944.  There is no mention of any jumpers to be changed for battery types.  I´m trying to get up to 24 hours life from an MKR1000. 

ballscrewbob

OK just a small update..

Day 4 of using a 1200 mAh lipo meant for a quad and just using the blink sketch as a reference.
Still going strong.

That's in total contrast to my earlier attempts.
Not sure what changed maybe something on the board defs or a firmware upgrade ?

Looks like the battery consumption issue is much better.
It may not be the answer you were looking for but its the one I am giving based on either experience, educated guess, google or the fact that you gave nothing to go with in the first place so I used my wonky crystal ball.

trewjohn2001

I´ve got up to 48 hours from a dual 18650 5000mAh battery pack - sketch is always connected to wifi with a status led and sending a simple UDP string when a button is pressed maybe 10 times per day.  48 hours is acceptable for me.  I´ve had to use a TP4056 for the charging as the MKR1000 isn´t up to the job of charging a 5000mAh battery pack in one sitting. 


ballscrewbob

Hi trewjohn..

Could you share a schematic for how you have it set up so others can see.
I have 18650's also. but prefer the copter lipo's

It may not be the answer you were looking for but its the one I am giving based on either experience, educated guess, google or the fact that you gave nothing to go with in the first place so I used my wonky crystal ball.

trewjohn2001

#11
Apr 07, 2017, 08:30 am Last Edit: Apr 07, 2017, 08:42 am by trewjohn2001
Hi Bob,

Sure but its very simple - I bought some cheap TP4056 modules on Ebay - they can supply 1amp so that should leave at least 800mA for charging the battery while the sketch is still running.  Thats about 7 hours to recharge - I would like a higher charge rate but at least it can charge and still run overnight.  

Its not ideal to have a parasitic load on the charge circuit but it seems to work ok.  The module is for a "service call" button and it will be mounted in a small wooden box to sit on a table so I didnt really want to run the risk of Lipo´s.  

I need to drop the status LED brightness down and there is probably some more power saving to be done.  48 hours is acceptable for the moment.

The JST connectors I bought online were wired reverse polarity to the MKR1000 board  :smiley-roll:


ballscrewbob

Thanks Trewjohn

I have some of those too for another battery circuit but it always good to let others see what we are using and how.

It may not be the answer you were looking for but its the one I am giving based on either experience, educated guess, google or the fact that you gave nothing to go with in the first place so I used my wonky crystal ball.

RoddyJoff

Hope this article is still active.

My understanding of MKR power supplies is that when powered from the micro-USB port and with a battery attached to the board socket then the MKR automatically charges the battery when required?

What is the advantage of a TP4056?

I intend to deploy an MKR with a solar panel attached to the USB and a battery connected to the board, is this not best practice?

ballscrewbob

Your understanding is correct about charging.

To use a solar charger you would have to use some small circuit either into the battery VCC and GND lines or a simpler method would be to use the micro USB port as you could feed from a regulated solar input of 5V.

The TP4056 if used as one of those Chinese modules (or similar) gives you that regulated charge that you would need to avoid over charging (bad thing with LiPo's).

There are similar modules that allow a closer match to a battery and depending on the battery capacity that would be a better option as they are usually have some adjustment or extra capacity.






It may not be the answer you were looking for but its the one I am giving based on either experience, educated guess, google or the fact that you gave nothing to go with in the first place so I used my wonky crystal ball.

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