JulianIan

Thanks a lot for your advice. I will build up the 18650 battery, when it arrives, and let you know how it goes. The fit for the existing battery is quite tight without a spring but several small coins might work. Best wishes

Yes, the Denon AP-30 measured close to 70 x 20 mm. I ordered one 20700 Li ion battery but it did not fit. I have ordered an 18650. What little 'trick' did you have in mind? Many thanks for your reply. It gives me encouragement that I am on the right track. The recorder/player works well and has good sound quality so I would be sad to loose it. Plus I have many MDs recorded from my LP collection.

Does anyone know what Li ion battery can replace the Denon AP-30 battery that came with the Denon DMP-R50? Be grateful for any information.