Income Taxes, Deferred Tax Assets and Deferred Tax Liabilities (Details 2) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Net operating loss carried forward	$ 27,442,842	$ 26,595,654
Valuation allowance	(31,142,217)	(30,523,274)
Deferred tax assets, non-current
Deferred tax liabilities, non-current
Trade accounts receivable [Member]
Deferred tax assets, non-current	1,008,784	1,031,389
Inventories [Member]
Deferred tax assets, non-current	1,773,613	1,715,161
Property, plant and equipment [Member]
Deferred tax assets, non-current	332,924	618,416
Provision for product warranty [Member]
Deferred tax assets, non-current	$ 584,054	$ 562,654