Not a lipo but well worth having. I put these in my 3cvs and they discharge very slowly. After a full nights heat last October I did not race again untill March and there was no need for me to recharge the pack.
Only £11.20 inc post from vapexteck.
6 months About 80% of charge is held
12 months About 70% of charge is held (normal nimh would be empty)
http://cgi.ebay.co.uk/TX-Pack-9-6v-N...3A1%7C294%3A30