Slim packs yes.. working on a couple of suppliers..... no info yet...

3 month wait - hopefully not... will know more in a week or so...

That said, JP are starting to do LiPos now for the indoor stuff so I might just order from there...less hassle and probably similar money..
22oz indeed - its all in the chemistry !

And thank fully the solution is gonna be less than half the original cost estimate (£260+ trade which is not a practical customer solution obviously).

Lets see... My YS powered C50 after a years hard service and patching up etc weights 5lbs dry. What does 9 fl oz of fuel weigh roughly?

50e with the new battery should weigh approx 4lb 14oz.