Abstract: A magnesium fuel cell with removable anodes and cathodes wherein the cathodes are enclosed in flat or curved frames or fixtures that are easily replaceable when damaged. The cathodes are designed to be particularly durable for heavy use. Multiple redundancies are incorporated that make the fuel cell less likely to fail and more suitable for use in places where other power sources are not available. The fuel cell is adapted for long use at low voltage levels and with a secondary battery with higher voltage that is continuously charged that in turn, can be used to charge other batteries.