"Also for Derby Cycle, the bestsellers for 2010 were: e-Bikes. Hence, the biggest product news was not one of the many highly sought-after bikes, but a Lithium-Ion 18 Ah battery, which is developed by Derby Cycle in cooperation with a German battery manufacturer."
http://www.bike-eu.com/news/4327/popular-derby-dealershow-grows-to-3rd-largest-german-trade-event.html