I contacted etronix support via website some time back to ask them about fitting a lipo to my pulse pro transmitter.
The reply was along the lines of they do not support fitting lipos as they maintain a high voltage for longer, when i replied that fitting 8 AA dry cells would take the voltage to 12v and a lipo was only 11.1v they did not reply.
on earlier mails, they said that you could not charge a lipo in the Tx as the maximum input Mah was to low, but again i said i would charge lipo in safe pouch out of transmitter, they just replied that no manufacturer supported Tx lipos.
I have not yet bought a lipo for mine but this is the link to one i'm watching on ebay :-
http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=110624760635
connectors are the same and dimensions are good to fit in.
If you try a lipo then please let me know how it gets on as i want my duracell rechargables for other things.