Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: How often do you need to change the batteries?
Document: My refrigerator smells awesome. It does need batteries changed every few months but really make opening your ref rig a pleasure.
This little device seems to work.It requires batteries and is stored in the fridge, where it produces small amount of ozone.We moved into an apartment with built in kitchen and an older refrigerator. Despite of cleaning it multiple times (soap, Clorox, vinegar) and letting it dry with open doors before, the refrigerator would give off an unpleasant whiff every time we opened the door. I put in baking soda in boxes. Hardly a change.
I like the idea of this, but I don't like using C batteries. It really didn't seem to last too long. It's a great idea, just not a very cheap one.
This machine makes your refrigerator smell great and helps you keep vegetables and fruits las longer. The only downside is the batteries don las long. But who cares, right??? Ill get new ones again.
Does a great job but batteries don't last longer than 3 weeks to aMonth if that! Might just have a defective unit but when it's actually working, it does make good stay fresh and got the stink out of a fridge when I moved into my house.
My Pure fridge deodorizer arrived promptly, and it is not too large and fits easily anywhere in your fridge. Once I installed the batteries (not included, size C) a little blue light started flashing on the top of the deodorizer.I called the supplier & someone promptly answered the phone!
Got it for Christmas.First impression - it is bigger than expected. I'm not sure why it is designed for use with C size batteries... I used shells (holders) for AA batteries and they work just fine instead of Cs. Secondly, oval shape looks ok but not practical for saving space.
The device works as advertised. I just have 1 issue that keeps from it being 5 stars. There is a blue light that blinks to tell you it is working, but it works in cycles so when it is in the off portion of its cycle, there is no light. So basically, I can't tell if it is working and won't be able to tell when it needs new batteries. I know it is working because I can tell the difference in my fridge.
I love this thing. Every time I open the frig I get a blast of fresh air AND it really works. I had an avocado in their for two weeks and it was perfect. I see the blue light flash and I know it's working. We'll see how long the batteries last. It is about the size of your hand, so it doesn't take up much room.
I have only have it a few weeks but I am impressed. When I open the fridge there is no odor! No oranges flavoring the butter or cheese (I've got to admit got shoved to the back and forgotten) scented anything. The amount of batteries required was a bit of a shock and required a trip out (sent the husband) but I'm hoping they will have a long life. Four &#34;c&#34; batteries by the way.
Answer: It has been in the fridge for about 2 months now and the red low battery light hasn't come on yet.  From my past experience, batteries will have to be changed every 4 months.  You will know because a blinking red light comes on.