An effective method of reducing the mass of a lead acid battery is to replace the lead with a less dense electrical conductor such as carbon. The application of a thin layer of lead onto the surface of carbon fibres can improve the electrical and mechanical properties of the bond between the fibre and battery active material. Under-potential deposition was used to apply a thin layer of lead onto carbon fibre tows. The efficiency of this process using a number of different electrolytes and voltage ranges was assessed. X-ray photoelectron spectroscopy and secondary ion mass spectroscopy were used to evaluate the deposition process. Lead was successfully deposited onto the surface of the fibres at a potential of approximately 262 mV using the electrolyte consisting of 0.1 M HClO4 and 0.01 M Pb(OAC)2.