Theragun Pro fourth generation battery ko.

Are you sure the battery charger works? After several years of use, depending on how many times a week and how long per use, rechargeable batteries have a limited life. Sealed units are designed for replacement of the entire unit. However, diyers with some skills can find replacement batteries, disassemble units, disconnect or desolder connections, remove batteries and put new ones in. This presumes a unit still operates and isn't damaged electrically or dropped, causing damage. A multimeter is very useful for measuring voltage. Here's a YouTube video that may help; duck://player/FL1XVRs7qmk.

Thanks for your reply. The charger and massager work perfectly. The problem is the internal batteries, which unfortunately are no longer available. I was interested in information on how to disassemble the battery unit to replace the internal batteries. Do you have any suggestions? The YouTube link you highlighted doesn't seem to be correct. Thanks.

The video help with direct and indirect applications. Direct for similar units, indirectly for clues. Clues; the method manufacturers use to hide fasteners and snap together designs for form, fit, function, fashion,, etc. Snap together plastics like electronic remote controls, cellphones and other things not requiring screws saves on manufacturing costs. Hidden screws are often covered by stick on labeling, plastic, or metal ornaments as a way to prevent disassembly for many items not designed for repairs. These are throw away items after several years of use. Batteries are available online with some searching once they're identifed after removal. A project like this may be for above average diyers familiar with tinkering, rechargeable devices with replaceable batteries and soldering skills. As designed, the Theragun not allowing battery replacement is a throw away. Finding a small appliance repair shop may give some info on costs for professional repairs that may cost more than simply buying a new one.