LiPo battery won't start Cyton board [resolved]

pirlapirla France
edited January 12 in Hardware

I bought several Lipo Batteries of two models :
3,7V 300 maH ,3,7V 600 maH
Despite they are charged ( 4,19v with tester , mA test with 4 leds +resistors in // (40ma several hours), when connected to Cyton (+on) : no blue light, no mA at all.
If i use the default battery pack (4 LR6) it'ok, but with 6v and 59mA for the board.
Doc says that a range 3-6V will be ok and some guys wrote they use a 3.7v battery.
So, what's wrong in my case ?
thanks for help.


  • wjcroftwjcroft Mount Shasta, CA

    Pirla, hi.

    Check the wiring of the connector on the end of your battery leads. Some companies reverse this polarity. If reversed, the Cyton or Ganglion will not operate. Because of an inline protection diode.

    Connector can be reversed, or re-spliced wires.


  • pirlapirla France

    Hi William,
    I check for polarity on lipo and battery pack and everything is ok with red + and black - !
    BUT i found the** JST type2 cables** i bought are not the same as the one with DIY pack: same size, same socket key but inverted polarity left-right:
    See image : on right the cable furnished with cyton board pack, on the left the commercial cables i bought :

    I don't know if there is several standards for jst type 2 , but at the entry of cyton, soket key on top, black wire- must be right and red+ must be left.
    I will wire an inverter ...
    Thanks for your help.


  • wjcroftwjcroft Mount Shasta, CA

    Yes, this is what I said previously. Red and Black wires are always plus and minus. But connector polarity has two choices. The one used by OpenBCI is more standard in the Maker community (Adafruit, etc.) I think the polarity you have may be more used in the radio controlled airplane crowd.

    These JST connectors have removable inserts. You can remove with the appropriate tool. Or just CUT the cable and re-splice.

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