A lubricant dispenser having a cartridge, a wall in the cartridge defining therein a lower chamber and an upper chamber, and a piston subdividing the lower chamber into a lower lubricant compartment and an upper gas compartment. The cartridge has an outlet opening into the lower lubricant compartment. A body of fluent lubricant fills the lower lubricant compartment. A housing in the upper chamber holds a gas generator connected through the wall to the gas compartment and electrically energizeable to generate gas and pressurize the gas compartment. A battery is secured to the housing. An electronic controller removably mounted in the upper chamber has electrical contacts connectable to the battery and to the gas generator. It is powerable by the battery for operating the gas generator and thereby pressurizing the gas compartment, moving the piston, and forcing the lubricant out of the outlet.