v3.25.1
Summary of Significant Accounting Policies - Narrative (Details)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2025
USD ($)
platform
Mar. 31, 2024
USD ($)
Dec. 31, 2024
USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Restricted cash equivalents included in prepaid expenses and other current assets $ 200 $ 0  
Restricted cash equivalents $ 1,256 1,256 $ 1,300
Number of primary battery platforms | platform 1    
Revenue $ 11,284 2,336  
Accounts receivable | Customer concentration risk | Four Customers      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Concentration risk percentage 71.00%    
Accounts receivable | Customer concentration risk | Two Customers      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Concentration risk percentage     50.00%
Revenue benchmark | Customer concentration risk | Customer One      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Revenue $ 2,900 500  
Revenue benchmark | Customer concentration risk | Customer Two      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Revenue 2,800 500  
Revenue benchmark | Customer concentration risk | Customer Three      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Revenue 1,600 $ 300  
Level 1 | Money Market Funds      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Cash equivalents $ 24,200   $ 23,500