Quarterly report pursuant to Section 13 or 15(d)

Segment information (Details)

v3.7.0.1
Segment information (Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Segment Reporting Information [Line Items]        
Net sales $ 51,699,930 $ 36,732,310 $ 93,566,778 $ 65,829,365
Cost of Sales 39,628,164 29,088,639 71,560,178 52,308,655
Gross profit 12,071,766 7,643,671 22,006,600 13,520,710
Lithium Batteries [Member]        
Segment Reporting Information [Line Items]        
Net sales 37,009,048 23,666,887 64,499,542 38,981,832
Cost of Sales 28,310,375 18,857,605 49,950,244 31,364,936
Gross profit 8,698,673 4,809,282 14,549,298 7,616,896
Ni-MH Batteries [Member]        
Segment Reporting Information [Line Items]        
Net sales 11,783,901 11,972,810 24,311,214 24,829,135
Cost of Sales 9,013,125 8,869,549 18,201,515 18,475,355
Gross profit 2,770,776 3,103,261 6,109,699 6,353,780
New Materials [Member]        
Segment Reporting Information [Line Items]        
Net sales 2,906,981 1,092,613 4,756,022 2,018,398
Cost of Sales 2,304,664 1,361,485 3,408,419 2,468,364
Gross profit $ 602,317 $ (268,872) $ 1,347,603 $ (449,966)