Meters are available which can test batteries under load.
GM had also tested batteries from a partnership of Continental AG and A123 Systems.
International Falls usually provides frigid conditions for car companies to test their brakes and batteries, clothes manufacturers to try out their parkas and boots, and cough-drop makers to experiment with new lozenges.
While on a research visit to Europe, Trahey used a glass cell that was very effective for testing lithium-air batteries.
It can even be used to test batteries.
With one, you can test batteries and switches, pinpoint causes of trouble in appliances and measure voltages at outlets.