So it used to be that if you had a flashlight with a (24/300) battery left and a light disposable battery (300/300) in your inventory you could just 'r’eload your flashlight and it would swap batteries. (If more than one battery was in range, it would prompt you to select).
Now it seems you can only reload a new battery if you first remove the old one. Otherwise you get the (confusing) message “You can’t reload anything with the ammo you have on hand”.
can confirm. doesn’t work with any battery related item
working theory is that its attempting to reload the battery like you would a gun magazine, and because you cant have charge freely in your inventory, it doesn’t know what to do.