Annual report pursuant to Section 13 and 15(d)

Other assets (Details Textual)

v3.7.0.1
Other assets (Details Textual) - Consumer Battery License Fee [Member] - USD ($)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Asset, Useful Life 20 years  
Amortization of Intangible Assets $ 50,000 $ 50,000
Finite-Lived Intangible Assets, Gross $ 1,000,000