Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Tables)

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Cash, cash equivalents and restricted cash

As there is no restricted cash at December 31, 2018 or 2017, there is no effect on the year ended December 31, 2018.



	December 31,
	2016		2015

Cash and cash equivalents	$	25,458	$	20,141
Restricted cash	1,124		11,667

Total cash, cash equivalents and restricted
cash shown in the statement of cash flows	$	26,582	$	31,808

Schedule of computation of potentially dilutive securities

For all periods presented in this report, convertible notes, stock options, and warrants were not included in the computation of diluted net loss per share because such inclusion would have had an antidilutive effect.



	Year Ended December 31,
Excluded potentially dilutive securities (1):	2018	2017	2016

Convertible note - principal	702,247	702,247	702,247
Consulting warrants to purchase common stock	—	—	486,364
Options to purchase common stock	1,694,068	578,813	915,572
Unvested restricted stock	96,623	180,951	—
Financing warrants to purchase common stock	2,340,828	2,340,828	3,316,208
Total potential dilutive securities	4,833,766	3,802,839	5,420,391


(1)	The number of shares is based on the maximum number of shares issuable on exercise or conversion of the related securities as of the period end. Such amounts have not been adjusted for the treasury stock method or weighted average outstanding calculations as required if the securities were dilutive.

Customers representing at least 10% of total revenue

Johnson Controls Battery Group, Inc. also represented a significant portion of our accounts receivable as of December 31, 2018 and 2017.



							Accounts Receivable
	Revenue						As of December 31,
	2018		2017		2016		2018		2017

Johnson Controls Battery Group, Inc.	88	%	96	%	—	%	95	%	95	%