RJ LaserPen won't charge

I have a 500 mW handheld laser therapy pen built by RJ Reiner GmbH. Have owned for 10 years but never able to get it to hold charge. Suspect built in battery only 'accessible via factory replacement’ back to Germany. Seems a lot of trouble if so

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Ted Annennberg do you have an exact model number for this unit? Post some pictures with your QUESTION of it so we can see what this all looks like. Adding images to an existing question

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