The first generation rechargeable alkaline batteries were introduced by Union Carbide and Mallory in the early 1970s.

A cathode paste is pressed into a steel can that forms the positive terminal of the battery.

Manufacturers do not support recharging of disposable alkaline batteries, and warn that it may be dangerous.

Pulsed charging appears to reduce the risk of electrolyte—usually potassium hydroxide (KOH)—leakage.

The charging current must be low to prevent rapid production of gases that can rupture the cell.

[9] Attempting to recharge a discharged alkaline battery can cause the production of gas within the sealed canister; pressure generated by rapid accumulation of gas can open the pressure-relief seal and cause leakage of electrolyte.

By driving a current through the battery in the reverse direction, the equilibrium can be shifted back towards the original reactants.

In particular, the metallic zinc generated by driving a reverse current through the cell will generally not return to its original location in the cell, and may form crystals that damage the separator layer between battery anode and electrolyte.

For example, incandescent lamps are much brighter when powered by rechargeable alkaline than by NiCd or NiMH batteries.

According to the websites of EnviroCell,[11] PureEnergy and old Rayovac packaging, these manufacturers' rechargeable alkaline batteries have no mercury or cadmium.