I got a Sena 10S for Christmas of '19.  I updated the software when it came out in January 2020.  It has been too cold and rainy to use it much, but each time I have a window to go riding it is dead.  I have fully charged my module and left it on the desk near my PC.  I leave it in the off condition and not attached to the helmet docking station.  How long should it hold a charge?  What causes the discharge?