I have the same problem, but worked out a solution. These days things are made to be thrown soon after their warranty, so we can keep the companies in business.
As an engineer I tried to put replacement rechargeable batteries. But that did not quite work as the built in charger connection goes faulty with calcium deposits and wear. Also the electric motor needs more than the meagre 2 volts from two AA batteries to provide any pressure. So I modified the connector and made provision to connect ..
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