The USB charger for bicycle dynamo B-CHARGE to be connected to the dynamo is now an indispensable accessory for those who go out in the saddle and never want to find themselves with a flat battery of their mobile phone, GPS navigator or tablet. Technology has taken over our beloved bicycles and having a satellite navigator or a smartphone with you is also a nice convenience, but electronic devices consume energy and batteries have little life. The solution to avoid discharging batteries is the USB charger for bicycle dynamo B-CHARGE , a small converter that transforms the alternating current into direct current where the current is produced by a bicycle dynamo (technically an alternator).