(US4708918-A)      Pb-acid battery positive plate has and acid resistant substrate at least partially coated with a conductive coating. At least part of the coated substrate is embedded in a fluid impervious polymer matrix which consists of a polymer with increased polarity relative to polypropylene.    Pref. the polymer is thermoplastic or thermoset material.    USE/ADVANTAGE -   Useful as bipolar plates which have a thin lightweight construction of good stability. (8pp)    (US4713306-A)      Battery element, useful in acid batteries, comprises an acid-resistant substrate of woven glass fibre (36), the strands of which (38) are coated with electrically conductive fluoride-doped Sn oxide. The body has a porosity of about 75% and average dia. of fibres is about 5 microns. Thickness of Sn oxide layer is about 1 micron and about 2 mol% of the coating is fluoride ion.    The lower part of the body is embedded in a layer (40) of synthetic, epoxy-type thermoset polymer to form a fluid-impervious, through-conductive substrate. The upper part of the body contains Pb oxide forming a positive active electrode layer (42), particles (44) of oxide being in contact with the strands. A layer (50) of Pb foil is adhered to the plate by an adhesive (52) and a layer of negative active material (54) such as Pb paste is supported by a sheet (56) of glass scrim.    ADVANTAGE -   Improved performance of both Pb-acid and bipolar plate Pb-acid batteries. (9pp)g    (US4787125-A)      In a process for at least partially coating fibres with an electrically conductive, fluorine-doped, tin-contg. coating (I) firstly, the fibres are contacted with a vaporous compsn. comprising at least one component of tin, and at least one fluorine-contg. component. Secondly the contacted fibres are contacted with an coating (I) on the fibre. The process provides that the fibres are maintained in constant three dimensional motion during the first and second process steps.    Pref. the fibres are glass fibres.    USE/ADVANTAGE -   Substrate so coated is useful in the prodn. of improved bipolar plate lead-acid batteries. (8pp)