You would have to ask the manufacturer directly: https://www.womanizer.com/ch...

Have you tried buying on eBay? You might be able to save money there. Otherwise, of course, contact the manufacturer or simply buy a new Womanizer (examples: lovetoy-erfahrung.de/neuheit-womanizer-pro/womanizerduo/ + Womanizer/starfire/test.de).

I would be interested to know how long you have been using your Womanizer, as far as I know the batteries last more than 10 years. I don't know how often you use it or whether you charge it incorrectly.