Basis of Presentation (Policies)	6 Months Ended
Basis of Presentation (Policies)	Sep. 28, 2025
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated condensed financial statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments except those otherwise described herein) considered necessary for a fair presentation have been included, unless otherwise disclosed. Operating results for the three and six months ended September 28, 2025 are not necessarily indicative of the results that may be expected for the fiscal year ending March 31, 2026. The Consolidated Condensed Balance Sheet at March 31, 2025 has been derived from the audited Consolidated Financial Statements at that date but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. The financial statements should be read in conjunction with the Consolidated Financial Statements and Notes thereto included in the Company’s 2025 Annual Report on Form 10-K (SEC File No. 001-32253), which was filed on May 21, 2025 (the “2025 Annual Report”). EnerSys (the “Company”) reports interim financial information for 13-week periods, except for the first quarter, which always begins on April 1, and the fourth quarter, which always ends on March 31. The four quarters in fiscal 2026 end on June 29, 2025, September 28, 2025, December 28, 2025, and March 31, 2026, respectively. The four quarters in fiscal 2025 ended on June 30, 2024, September 29, 2024, December 29, 2024, and March 31, 2025, respectively. The Consolidated Condensed Financial Statements include the accounts of the Company and its wholly-owned subsidiaries and any partially owned subsidiaries that the Company has the ability to control. All intercompany transactions and balances have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. These estimates and assumptions take into account historical and forward looking factors that the Company believes are reasonable, and the Company’s estimates and assumptions may evolve as conditions change. Actual results could differ from those estimates. Examples of significant estimates include the allowance for credit losses, the recoverability of property, plant and equipment, the incremental borrowing rate for lease liabilities, the recoverability of intangible assets and other long-lived assets, fair value measurements, including those related to financial instruments, fair value of goodwill and intangible assets, valuation allowances on tax assets, production tax credits under the Inflation Reduction Act, pension and postretirement benefit obligations, contingencies and the identification and valuation of assets acquired and liabilities assumed in connection with business combinations.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In December 2023, the Financial Accounting Standards Board issued a final standard on improvements to income tax disclosures. The standard requires disclosure of specific categories within the effective tax rate reconciliation and details about significant reconciling items, subject to a quantitative threshold. The standard also requires information on income taxes paid disaggregated by federal, state and foreign based on a quantitative threshold. The standard is effective for fiscal years beginning after December 15, 2024. Early adoption is permitted. The standard is applied prospectively with an option for retrospective adoption. The Company is currently evaluating the impact of adopting this standard on its disclosures. In November 2024, the Financial Accounting Standards Board issued a final standard on disaggregation of income statement expenses. The standard requires disclosure of more detailed information about certain costs and expenses in the notes to the financial statements. The standard is effective for fiscal years beginning after December 15, 2026 and for interim periods beginning after December 15, 2027. Early adoption is permitted. The standard is applied prospectively with an option for retrospective adoption. The Company is currently evaluating the impact of adopting this standard on its disclosures.