The most reliable and best rechargeable batteries are the Ipower 9v batteries. I have been using them since 2006 and they have saved me a ton of money and saved the environment 1000’s of alkaline batteries. Thought most of my equipment now takes AA batteries Ipowers are still an important part of my workflow. I use them in my LMA transmitters for my wireless camera link which they last up to 6 hours in and they will power a Comtek easily for a whole day. If you haven’t tried any rechargeable batteries yet the Ipowers will be a great start. See the link below for more information:
Ipower Rechargeable 9V are still the best bet
Pro Location Sound LLC 