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Thread: Power Teensy 3.6 with lipo battery?

  1. #1
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    Power Teensy 3.6 with lipo battery?

    Hi!

    I'm currently powering my Teensy 3.6 with a 5V booster from my lipo battery. I want to know if I can power it directly with the power from the lipo battery because the pinout sheet says VIN (3.6V - 5.5V). My lipo will be running from 4.2V down to 3.2V where I cut it off.

    Can I apply the lipo directly to the VIN? What happens below 3.6V? I already cut the trace for the VUSB.


    Thanks!

  2. #2
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    This (more or less) what I'm doing, albeit with a Teensy LC.
    It works fine down to 3.3V, at full clock speed (48 MHz). Did not try under 3.3V.
    I seem to remember that Teensies 3.x have some sort of "regulator bypass" when Vin drops below say 3.3V, so actually if you apply 3.2V to VIN it just works without dropping to an unsuitable voltage.

  3. #3
    Senior Member+ MichaelMeissner's Avatar
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    Many of us power our Teensies with lipo batteries.

    If you want to incorporate battery charging with the lipo (connecting the VUSB pin to charge the battery) there are several options:

  4. #4
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    Quote Originally Posted by XFer View Post
    This (more or less) what I'm doing, albeit with a Teensy LC.
    It works fine down to 3.3V, at full clock speed (48 MHz). Did not try under 3.3V.
    I seem to remember that Teensies 3.x have some sort of "regulator bypass" when Vin drops below say 3.3V, so actually if you apply 3.2V to VIN it just works without dropping to an unsuitable voltage.
    This sounds great. So it seems that down to at least 3.3V it should work? Is the only thing that under 3.6V the on board 3.3V regulator might not work?

  5. #5
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    Quote Originally Posted by MichaelMeissner View Post
    Many of us power our Teensies with lipo batteries.

    If you want to incorporate battery charging with the lipo (connecting the VUSB pin to charge the battery) there are several options:
    Thank you. I like this small form factor but I already got a charger board. Will look more into this small charger add on for projects in the future!

  6. #6
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    Quote Originally Posted by Marius19992 View Post
    This sounds great. So it seems that down to at least 3.3V it should work? Is the only thing that under 3.6V the on board 3.3V regulator might not work?
    Yes, the onboard regulator is bypassed in this situation.
    If you apply 3.3V to VIN, not only the Teensy works correctly; you also have 3.3 - 0.025V = 3.275V at the "3.3V" pin! So very little voltage drop.
    Teensies are little gems.
    EDIT: just tried with a Teensy 3.2. Works OK with 3.25V supplied to VIN. And I read 3.225V at the "3.3V" pin. So I can confirm.
    Last edited by XFer; 04-18-2019 at 04:44 PM. Reason: Just tested first-hand

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