When I add any electronic item to by bug out bag, I try to ensure I do not vary the types of batteries. Why? Very simply, to keep it simple. For the most part, any electronics I do carry are AA. This is because AA is common and I also have a goal zero solar panel charger that charges AA size batteries. However, sometimes you just can’t get around the occasional piece of equipment that does not operate on AA. That is where battery conversion kits make up the difference! It is a very simple housing that multiple smaller batteries can fit in to to make up the size of a larger battery and cost only $4 to $10 per pack. Keep in mind that you do not get the same power out of these smaller batteries compared to a larger one. This is simple a way to be able to harmonize your battery stash to be used in multiple pieces of equipment or charge them via a solar charger.
For added knowledge, know that AA, AAA, C & D batteries have a 1.5 voltage. So the only negative side effect to using an adapter like AAA to AA is less battery life.
Many people are on the forums asking about a conversation from AA to CR123 (or vice versa) which is becoming a very popular choice of battery for flash lights and night vision. For the CR123 battery, you need to check the manufacturer of the equipment for compatibility with AA. CR123 has 3V charge while the AA only has 1.5V. You might be able to use an AA in a CR123 housing, but it will have diminished performance. The equipment might not even work at all if it has a low voltage cut off sensor. Also recognize that you cannot charge a CR123 in an AA charger even if it fits because of the voltage difference.
If you are interested in the goal zero charger for charging AA batteries (or AAA with the conversion kit above) you can see it below on Amazon.