okay people, forget about what you read on the internet use your own knowledge of chemistry, batteries have acid, ionic bridge and etc, basically.. acid being cooled down to sub-zero temperatures will basically be "freezing in time" yes it will save your batteries for longer, you can keep them in the freezer just for storage, however theres one problem, melting. When you take out cold batteries out they will start collecting moisture on them because of condensation and humid air, when u unfreeze them put them in the fridge for a day, then take them out of the fridge and put them in a plastic bag thats sealed so that outside air doesnt cause condensation, once they are room temperature shove them in the laser.
honestly you could experiment by putting them inside ur laser right away and closing the lid since most of your lasers are air sealed it shouldnt condensate inside..
and finally, why freezer? keeping them in fridge is enough, like old ppl keep their medicine, freezing is a little extreme and hard to maintain