Geoff,
PM'd you, but both the 320 and the FFR 321 were excellent sets and simple to use compared to the A41 old sets. Far greater range and a MUST if you are a HAM radi enthusiast.
I think MOD made a big mistake putting these out to civvy purchase, but heyho it will be like the SA80 they'll be hunting people down one day who own one of these two sets they are that good.
Batteries with everything Military always take a back seat but some thought as Peter alluded to, was made when they designed these.