摘要 |
1372214 Indicating state of charge of lead/ acid battery VARTA AG 19 Nov 1971 [20 Nov 1970] 53913/71 Heading H1B The swelling of an ion-exchange membrane in accordance with the pH value of the electrolyte in which it is immersed, is used to give an indication of the state of charge of a lead-acid battery. In one embodiment, the membrane, of sulphonated polystyrene, is in the form of a narrow elongated strip under tension, and its change in length with pH of the electrolyte moves a pointer over a scale indicating charge condition. |