Remove detachable electronics only according to the item's instructions, and machine-wash the textile only if the maker explicitly permits it afterwards. A removable-looking battery pack does not establish that every other component is washable.
Understanding this situation
Heated garments, lights, speakers and wearable devices can include hidden wiring or parts that remain sensitive to water. Washing them can also introduce a separate hazard to the appliance.
A useful next step
Check the complete product guidance before loading. If an electronic item or battery has accidentally gone through a wash, stop using the affected equipment and seek the appropriate product advice. Do not charge or heat a wet battery to test it.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.