Bought the helmet at Sturgis last year.  Started having issues charging it in January where after a full day of riding I plugged it in to charge and got a blue light right away.  Charged it all night and it only blinks twice, maybe three times, when unplugging it and checking the charge.  Sena say to box it up and send it to California at my expense for servicing it and to be returned at my expense.  To me that's poor warranty service.  Since I have updated the firmware twice and the issue remains, I will buy a replacement battery to see if that works.  So far we are not pleased with Sena Technology.