Note 6 - Supplemental Balance Sheet Information (Tables)

3 Months Ended

Mar. 31, 2020

Notes Tables

Cash, Cash Equivalents and Investments [Table Text Block]

	March 31 ,		December 31,
	20 20		201 9
Cash	$	5,862	$	7,135
Restricted cash		247		270
Total	$	6,109	$	7,405

Schedule of Inventory, Current [Table Text Block]

	March 31 ,		December 31 ,
	20 20		201 9
Raw materials	$	18,354	$	18,485
Work in process		3,036		2,548
Finished goods		7,589		8,726
Total	$	28,979	$	29,759

Property, Plant and Equipment [Table Text Block]

	March 31 ,			December 31,
	20 20			201 9
Land	$	1,273		$	1,273
Buildings and leasehold improvements		8,096			8,148
Machinery and equipment		62,239			62,562
Furniture and fixtures		2,105			2,112
Computer hardware and software		6,520			6,528
Construction in process		5,078			4,730
		85,311			85,353
Less: Accumulated depreciation		(63,272	)		(62,828	)
Property, plant and equipment, net	$	22,039		$	22,525

Schedule of Goodwill [Table Text Block]

	Battery & Energy			Communications
	Products			Systems		Total
Balance – December 31, 2019		15,260			11,493		26,753
Effect of foreign currency translation		(285	)		-		(285	)
Balance – March 31, 2020	$	14,975		$	11,493	$	26,468

Schedule of Finite-Lived Intangible Assets [Table Text Block]

	at March 31 , 20 20
			Accumulated
	Cost		Amortization		Net
Trademarks	$	3,402	$	-	$	3,402
Customer relationships		8,922		4,768		4,154
Patents and technology		5,458		4,874		584
Distributor relationships		377		377		-
Trade name		1,487		222		1,265
Total	$	19,646	$	10,241	$	9,405

	at December 31, 201 9
			Accumulated
	Cost		Amortization		Net
Trademarks	$	3,403	$	-	$	3,403
Customer relationships		9,080		4,721		4,359
Patents and technology		5,521		4,869		652
Distributor relationships		377		377		-
Trade name		1,511		204		1,307
Total	$	19,892	$	10,171	$	9,721