I have an H501s. The transmitter takes 4 AA batteries or one can use other batteries with a compatible connector. I have 2 such batteries: one is a 1300mAh 7.4v 2C 9.62Wh and a 1400mAh 7.4v 1C 10.36Wh. Other than the ability to recharge, what are the pros and cons of AA versus the other 2. Thanks again in advance for your willingness to share your knowledge.