Annual report pursuant to Section 13 and 15(d)

Consolidated Statements of Stockholders' Equity (Deficit)

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
Balance at beginning at Dec. 31, 2014	$ 4	$ 1,600	$ (2,374)	$ (770)
Balance at beginning (in shares) at Dec. 31, 2014	4,363,641
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued upon initial public offering ("IPO"), net of offering costs	$ 7	29,891		29,898
Common stock issued upon initial public offering ("IPO"), net of offering costs (in shares)	6,600,000
Common stock issued for over allotment of the IPO, net of offering costs	$ 1	2,963		2,964
Common stock issued for over allotment of the IPO, net of offering costs (in shares)	641,930
Conversion of convertible notes and accrued interest upon completion of the IPO	$ 2	6,277		6,279
Conversion of convertible notes and accrued interest upon completion of the IPO (in shares)	2,511,871
Extinguishment of benficial conversion feature derivative liability		6,280		6,280
Reclassification of financing warrants (from derivative liability to APIC) upon completion of IPO		881		881
Stock based compensation - stock options		301		301
Stock issued for consulting services		98		98
Stock issued for consulting services (in shares)	20,000
Warrants issued for consulting services		65		65
Net loss			(12,331)	(12,332)
Balance at end at Dec. 31, 2015	$ 14	48,356	(14,705)	33,665
Balance at end (in shares) at Dec. 31, 2015	14,137,442
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation - stock options		1,060		1,060
Warrants issued for consulting services		138		138
Cashless exercise of warrants (in shares)	15,203
Exercise of options to purchase common stock		19		$ 19
Exercise of options to purchase common stock (in shares)	4,500			4,500
Common stock issued in May 2016 Private Placement, net of $345 offering costs	$ 1	4,777		$ 4,778
Common stock issued in May 2016 Private Placement, net of $345 offering costs (in shares)	719,333
Common stock issued for cash in May 2016 from Interstate Battery, net of $629 allocated transaction cost	$ 1	4,369		4,370
Common stock issued for cash in May 2016 from Interstate Battery, net of $629 allocated transaction cost (in shares)	702,247
Common stock issued in November 2016 public offering, net of $1,688 offering costs	$ 2	21,540		21,542
Common stock issued in November 2016 public offering, net of $1,688 offering costs (in shares)	2,300,000
Proceeds allocated to warrants issued and beneficial conversion feature in connection with Interstate Batteries Agreement		4,975		4,975
Net loss			(13,557)	(13,557)
Balance at end at Dec. 31, 2016	$ 18	85,234	(28,262)	56,990
Balance at end (in shares) at Dec. 31, 2016	17,878,725
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation - stock options		1,081		1,081
Cashless exercise of warrants	$ 1	(1)
Cashless exercise of warrants (in shares)	1,173,296
Exercise of warrants to purchase common stock		15		15
Exercise of warrants to purchase common stock (in shares)	2,500
Exercise of options to purchase common stock		1,071		$ 1,071
Exercise of options to purchase common stock (in shares)	284,370			284,370
Common stock issued under Officers and Directors Purchase Plan		8		$ 8
Common stock issued under Officers and Directors Purchase Plan (in shares)	2,404
Common stock issued for purchase of Ebonex IPR Limited		2,149		2,149
Common stock issued for purchase of Ebonex IPR Limited (in shares)	123,776
Common stock issued in December 2017 public offering, net of $1,256 transaction cost	$ 7	13,752		13,759
Common stock issued in December 2017 public offering, net of $1,256 transaction cost (in shares)	7,150,000
Net loss			(26,580)	(26,580)
Balance at end at Dec. 31, 2017	$ 27	$ 113,780	$ (54,842)	$ 58,965
Balance at end (in shares) at Dec. 31, 2017	27,554,076