Will freshly-charged rechargeable batteries lose that charge if those batteries sit unused in a drawer for two or three months?
Yes. All battery chemistries have what is called a “self discharge” rate. This rate determines how long a battery can hold its charge when not in use (for instance, sitting in a drawer). Certain types of batteries are better then others, and work is being done to reduce the amount of self discharge that some batteries have. In general, rechargeable batteries have a higher self discharge rate then non-rechargeable batteries.