
	Estimated Useful lives	September 30, 2024		December 31, 2023
Equipment	5 to 10 years	$	51,831	$	20,559
Finance lease	5 years	504		504
Furniture	5 to 10 years	2,283		2,103
Leasehold improvements	Lesser of useful life/ remaining lease	9,047		7,718
Tooling	2 to 3 years	9,483		7,045
Construction in progress (“CIP”)		82		17,958
Total		73,230		55,887
Less: Accumulated depreciation		(21,684)		(18,032)
Total property, plant and equipment, net		$	51,546	$	37,855

Depreciation expense related to property, plant and equipment was $2,669 and $2,144 for the three months ended September 30, 2024, and 2023 and $5,193 and $7,255 for the nine months ended September 30, 2024 and 2023, respectively.

The Company recorded a loss from write-down of property, plant and equipment of $3,192 and $955 for the three months ended September 30, 2024, and 2023, and $3,528 and $7,151 for the nine months ended September 30, 2024, and 2023, respectively. The 2023 write-downs were mainly due to replacement of equipment, outsourcing of certain production processes and the shift in production from the Gen 2.3 battery system to the Z3™ battery system. The 2024 write-downs were primarily related to design changes from the Z3™-Phase 1 to Z3™-Phase 2 production in which the Phase 1 production assets could not be utilized or repurposed for Phase 2 production.

On June 28, 2024, the Company successfully began commercial operations on the first manufacturing line. Accordingly, the assets classified as construction in progress were reclassified to equipment, leasehold improvements, furniture and tooling as of June 28, 2024. Included in construction in progress prior to the reclassification were capitalized interest costs of $1,841 for the nine months ended September 30, 2024. There were no capitalized interest costs recognized for the three and nine months ended September 30, 2023 and for the three months ended September 30, 2024.