XML 22 R12.htm IDEA: XBRL DOCUMENT v3.22.1
Balance Sheet Components
 3 Months Ended
Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Balance Sheet Components Balance Sheet Components
Cash and cash equivalents consisted of the following (in thousands):
March 31, 2022December 31, 2021
Cash
$10,984 $17,065 
Cash equivalents
36,380 152,974 
Total cash and cash equivalents
$47,364 $170,039 

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets to the total of such amounts shown on the statements of cash flows. The restricted cash is primarily collateral for performance bonds issued to certain customers. The collateral is provided in the form of a cash deposit to either support the bond directly or to collateralize a letter of credit that supports the performance bonds.
March 31, 2022December 31, 2021
Cash and cash equivalents
$47,364 $170,039 
Restricted cash, current portion
12,105 12,105 
Restricted cash, net of current portion
460 460 
Total restricted cash
12,565 12,565 
Total cash and cash equivalents, and restricted cash
$59,929 $182,604 

Inventories consisted of the following (in thousands):
March 31, 2022December 31, 2021
Raw materials
$68,964 $65,225 
Work in progress
31,534 25,062 
Finished goods
21,559 18,269 
Service parts
6,330 6,000 
Total inventories
$128,387 $114,556 
The write-down of excess or obsolete inventories to cost of goods sold was immaterial for the three months ended March 31, 2022, and $0.5 million for the three months ended March 31, 2021.
Property, plant, and equipment, net, consisted of the following (in thousands):
March 31, 2022December 31, 2021
Computer hardware
$5,230 $5,195 
Computer software
9,619 9,561 
Internally used vehicles and charging systems
16,889 16,459 
Leased vehicles and batteries
6,714 6,863 
Leasehold improvements
10,607 10,516 
Machinery and equipment
28,474 28,302 
Office furniture and equipment
1,889 1,861 
Tooling
21,939 21,726 
Finance lease right-of-use assets
179 179 
Construction in progress
30,482 20,243 
132,022 120,905 
Less: Accumulated depreciation and amortization
(61,873)(58,659)
Total
$70,149 $62,246 
Construction in progress was comprised of various assets that are not available for their intended use as of the balance sheet date.
Depreciation and amortization expense were $3.4 million and $3.8 million for the three months ended March 31, 2022 and 2021, respectively.
Accrued liabilities consisted of the following (in thousands):
March 31, 2022December 31, 2021
Accrued payroll and related expenses
$6,353 $8,069 
Accrued sales and use tax
708 885 
Warranty reserve
7,389 8,116 
Accrued audit and accounting related expenses
472 783 
Accrued charger installation costs
443 579 
Other accrued expenses
951 2,202 
Total
$16,316 $20,634 
Other long-term liabilities consisted of the following (in thousands):
March 31, 2022December 31, 2021
Warranty reserve$15,292 $15,158 
Finance lease liabilities, non-current79 87 
Total$15,371 $15,245