One embodiment of the present subject matter includes an apparatus including a non-thin-film battery, the apparatus including a cylindrical implantable housing, electronics disposed in the implantable housing, and a battery disposed in the implantable housing, the battery comprising: a stack including at least one substantially planar anode having a thickness greater than 1 micrometer and at least one substantially planar cathode having a thickness greater than 1 micrometer, a housing enclosing the stack of substantially planar anodes and cathodes, and terminals interconnecting the battery and the electronics, wherein the battery has a volume of less than 0.024 cubic centimeters. The present subject matter includes an implantable medical device having a bobbin battery.