Spinning disc sprayers have been in widespread use in some countries for a number of years. Whilst the machines have become somewhat more economical in battery usage, the cost of disposable batteries has increased markedly. Erratic supplies of poor quality disposable batteries in some areas has also restricted the growth of this spraying method. This paper discusses the merits and problems relating to primary (disposable) and secondary, (rechargeable) cells together with a variety of possible recharging methods. A series of tables summarizes information presented in the text to permit easy comparison of the features of each power source and recharging method where appropriate. Further tables give costing examples (U.K. values) for various power source/recharging combinations and show the range of costs, relative to hydraulic spraying per hectare per annum when taking labour costs, batteries etc. into consideration. The possibility of recharging existing primary cells is considered but is thought likely to be impractical in most situations. However, resting batteries to increase useful life is likely to be of benefit.