How to reassemble so that the battery contacts are firm?

I have two Oral-B Cross-Action electric toothbrushs. The situation is exactly the same with both, so I am sure it isn’t a defect.

Each comes with a AA battery and it is time to replace them. However, when I unscrewed the bottom to remove the spent battery a loose plastic piece came out. I have tried every conceivable configuration to put the plastic piece in while screwing the handle back together. Nothing works to apply the pressure required for the battery contact to engage. I suspect this was designed to be exceedingly difficult to reassemble, which is infuriating for anyone that cares about plastics and the waste economy.

The metal contact just needs to be pressed into the (-) of the battery by the screwing action of the hollow ~conical handle piece. I would be so grateful to anyone who has figured out a solution to this.

Best,

Adam

Thank you T RAGE!

I was skeptical, but it worked. I used some paper and shaped it to fit in the hollow cone with a flat bottom.

Holding the unit upside down I positioned the plastic bit as you can see in the photo and carefully screwed it back together.