Battery Life

There are several possible answers to the question. The first and simplest is that the battery your brother uses for his CIC is larger than the one you use. CIC hearing aids most commonly use size 5 (red label) and size 10 (yellow label) batteries. The size 10 has about 2.6 times the capacity or hours of service in industry standard tests than a size 5 has.

The second reason is a little more complicated. Assuming you are both using exactly the same size and brand of battery, then the reason for 60% shorter run time in your hearing aid is that your CIC is more than twice as powerful as your brothers. Therefore, it uses the stored energy if the battery in less than half the time it takes to use it up in your brothers aid. The other consideration might be how long each day you use the aid compared to how long he does. If you have the aid in use for 16 hours per day and he only uses it seven you will get less than half the number of days use out of the same battery than he will.