Lithium-ion battery pack chargeable by alkali charger

The battery pack comprises at least one accumulator (5), two external connection terminals, one of which is positive (2) and the other negative (3), and a safety circuit (4) connected to prevent any charging current from entering the accumulator (5) as soon as a voltage applied between said external connection terminals exceeds a certain maximum safety voltage. An additional protective circuit (1) is furthermore connected between the external terminals (2,3) and the safety circuit (4) to prevent any charging current from entering said safety circuit (4) as soon as the voltage applied between said external connection terminals exceeds a certain maximum charging voltage, this maximum charging voltage being lower than the maximum safety voltage. This construction prevents the safety circuit from operating inadvertently.