Ad hoc announcement pursuant to Art. 53 LR

YVERDON-LES-BAINS, Switzerland, 23^rd of September, 2026 – Leclanché SA (SIX: LECN) (“Leclanché” or the “Company“) one of the world‘s leading energy storage companies, announces that it had to file an insolvency application for its two German subsidiaries, Leclanché GmbH and Leclanché Services GmbH.

The reason for filing for the insolvency application with the Local Court of Offenburg is due to the illiquidity situations of both German subsidiaries with regard to Section 17 of the German Insolvency Code (Insolvenzordnung, InsO). The insolvency petition was filed purely as a precautionary measure, as it has not yet been possible to secure further funding for the companies in good time. Should funding be obtained at short notice and the grounds for insolvency be resolved as a result, it may be possible to withdraw the insolvency application. This would allow the company to continue its operations without the constraints of formal insolvency proceedings

The applications were required as both subsidiaries faced a cash shortfall. Leclanché SA continues to pursue short-term funding to support the Group’s going-concern requirements and, if the subsidiaries’ illiquidity is remedied, to seek withdrawal of the insolvency applications. The Company is in active discussions with customers that have indicated a willingness to provide further support, as well as with strategic partners and potential investors.

The Company’s customer order book remains strong and has grown in recent months. While Leclanché maintains a positive long-term outlook, it continues to face significant short-term financing, cash and production-capacity constraints. The Company is working closely with partners to address its funding needs.

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About Leclanché

Leclanché is a world leading provider of low-carbon footprint energy storage solutions based on lithium-ion cell technology. Established in 1909 in Yverdon-les-Bains, Switzerland, Leclanché’s history and heritage is rooted in battery and energy storage innovation. The company’s Swiss culture for precision and quality, together with its production facilities in Germany, make Leclanché the partner of choice for companies seeking the very best in battery performance and who are pioneering positive changes in how energy is produced, distributed and consumed around the world. Leclanché is organised into three business units: energy storage solutions, e-Mobility solutions and specialty battery systems. The company currently employs over 350 people with representative offices in eight countries around the world. Leclanché is listed on the Swiss Stock Exchange (SIX: LECN).

SIX Swiss Exchange : ticker symbol LECN | ISIN CH 011 030 311 9

Disclaimer

This press release contains certain forward-looking statements relating to Leclanché’s business, which can be identified by terminology such as “strategic”, “proposes”, “to introduce”, “will”, “planned”, “expected”, “commitment”, “expects”, “set”, “preparing”, “plans”, “estimates”, “aims”, “would”, “potential”, “awaiting”, “estimated”, “proposal”, or similar expressions, or by expressed or implied discussions regarding the ramp up of Leclanché’s production capacity, potential applications for existing products, or regarding potential future revenues from any such products, or potential future sales or earnings of Leclanché or any of its business units. You should not place undue reliance on these statements. Such forward-looking statements reflect the current views of Leclanché regarding future events, and involve known and unknown risks, uncertainties and other factors that may cause actual results to be materially different from any future results, performance or achievements expressed or implied by such statements. There can be no guarantee that Leclanché’s products will achieve any particular revenue levels. Nor can there be any guarantee that Leclanché, or any of the business units, will achieve any particular financial results.

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