I am not sure if there is a dealer for these in the UK (they are made in the USA)http://antigravitybatteries.com/ag-401/
Compared to other Lithium Iron Phosphate batteries these are very reasonably priced. You will need
proper charger. My experience is that 5Ah minimum capacity is about right with the FT-817 for a days outing.
I also recommend reading KA7OEI's web page on FT-817 power consumption : http://www.ka7oei.com/ft817_pwr.html
There are quite a number of tricks to reducing battery consumption while operating portable
(like using the front BNC connector rather than the rear SO-239 ... draws an extra 30ma to
energize a non-latching relay).
Can anyone recommend a lightweight battery for the FT-817 when going portable? Even running 2.5 watts, the built in battery seems to last a VERY short time. I have got some 7Ah sealed lead acid batteries, but they are very heavy to carry.
I will be running SSB rather than FM so that should help battery life. A direct replacement that would fit inside the radio would be ideal. Does anyone know of such a battery?
Jonathan, M5AEO, London.