Battery rest insulators were use in conjunction with wet cell batteries in many turn-of-the-century electric applications. The rest insulators were used to help prevent the wooden floors, upon which the battery stands rested, from acid and electrical leakage. The wells in the battery rests, many of which were filled with oil, would hold the runoff from the chlorides that may have seeped from the battery. A popular term of early hobby days has nicknamed these insulators "bird feeders."