Aye but they are low cycle devices and also the voltage drops after every discharge and charge cycle depending how much you drain them by.
You only get 5-6 recharges if you completely discharge them and by the second or third charge cycle the voltage is to low to drive the headset.
Pretty much every pro pilot has started out down this route some get a days worth out of the rechargeable and then carry a couple of spares and rotate them which is fine if you get home every night. But the majority in the end get fed up with all the hassle and go back to disposable ones. Tight Scottish gits buy them in bulk but most just pick up a pack of batteries when they see and need them. AA's are pretty easy as most airports sell them and 24 hour garages. 9v ones can be a bit of a pain which is why I carry 4 of them. One for me one for the FO if they run out and a couple of spares because they fit in the box anyway.
opps just seen the OP is from NZ I will leave the links anyway for the UK folk.
I am sure you can find a bulk cheap battery wholesale industrial supplier in NZ.
Last edited by mad_jock; 13th Sep 2013 at 08:29.