Manuscript, 'On charging secondary batteries' by W H [William Henry] Preece Preece writes: 'I have for some months past been experimenting with secondary batteries with a view of getting an efficient, uniform, and constant source of currents for electric lighting my house, and I have succeeded beyond my expectations. Some new facts have developed themselves during my experience, which I have thought of sufficient importance to bring before the Society [...] The cells are of the Planté type, manufactured by the Elwell Parker Company of Wolverhampton [England].' Annotations in pencil and ink. Includes five diagrams of experimental apparatus and results and five prints of the same. Subject: Electricity Received 6 May 1885. Read 21 May 1885. A version of this paper was published in volume 38 of the Proceedings of the Royal Society as 'On charging secondary batteries'. 1885