I fully charge my batteries with the external Canon charger. When I check them with multimeter, they show a full 8V charge. When I put in camcorder, however, they drain in about 2-3 minutes. Then when I check the "dead" battery with multimeter again,...
It basically happened with four different old batteries: external charger indicates battery is fully charged, measurement on multimeter says 8V, put it in camcorder and roll camera - the battery charge icon on the camcorder screen rapidly drops down ...