Powering Teensy 3.6 using a power bank


I have a Teensy 3.6, and previously I have connected an ADXL345 to it and it recorded onto the SD card when it was plugged into an Output 5V-1A (5W) power bank…however now, I have the teensy connected to an ICM20649 (sampling at 9000 samples a second) and it won’t record onto the SD card, although it will record with the same code onto the SD card when connected via the usb port on my Laptop (MacBook Pro). I don’t know if anyone else has had this problem? Thank you in advance for your help!

Hi Chantelle, welcome to the forum!!

Weird issue! Any chance you can send through some pics of your hardware, and any code you’re running?

At a glance, the two issues that come to mind is some step in the code where it waits for a serial connection to a computer that never appears, or maybe the power bank is not “detecting” the teensy and just not supplying power (some require a button press to get going). Ideally, the teensy 3.6 uses arouuund 100mA while in use, so it shouldn’t max out a power bank for sure (And a usb port usually can’t provide as much)

Keen to see if anyone has other suggestions!

Hi James! Thank you for your reply, I really appreciate it. I have uploaded an image of the current set-up. The sensor lights up showing it has power… The code is a bit more complicated to upload… I find it really weird that it all works perfectly when it’s plugged into my laptop then doesn’t when its plugged into the power bank, and only with this sensor! I thought maybe someone else might have had the same issue.


Hey Chantelle,

Hmm that is sounding like a bit of an odd one…

Are you able to send through the code or any resources/tutorials you’re trying to implement? We might be able to do a bit of troubleshooting with some more intel!

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I have a huge Goal Zero battery bank I use to power some neopixel projects and I’ve noticed it won’t supply power or turn on just by connecting my project via USB. Until it registers a large enough load it doesn’t wake up and supply power via USB. I also have a few cheap battery banks from officeworks and they will wake up and supply at a much lower load.

Perhaps you can rule out the power supply as the issue by using something like a phone charger to supply the project. If it works with a phone charger or Macbook but not the battery bank, then it must be the battery bank.

Otherwise it may be that the Macbook is supplying a better ground reference for the project and your project is floating when connected via battery.


Hi all
Power banks can be a bit “dirty” too. They are ok to charge phones etc but the one I have is a Cygnet 15000mAh which is anything but “clean” under light loads. Lots of switching artefacts. Bur having said that it does the job it was designed for very well. Don’t forget these things are designed as a charger and not a power supply to power electronic things.
Could be that particular sensor type does not like a bit of rubbish on the supply
Do as Trent suggests. Try other power sources and if they work your problem is using that supply. Keep in mind though if this is the case there is probably not the fault of the power bank. It is being used for something it is not designed to do.
Cheers Bob


Hi Guys,
Thank you so much for all your help. Yeah I totally agree to not blame the power bank at all and i’ll do as Trent suggested and try other power supplies. I just thought it was really weird and wanted to see if others had experienced the same. Thank you so much for everyones input!! I really appreciate it :slight_smile:

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