HEy, I have had battery issues also in the last couple of days,
When you jump an R33 its best to do it from the engine bay, take of the little cover thing and add the red jumper lead to the + and the black one to the -- a little black metal earth.
Funny story for ya, was trying to kick my 33 over from a jump from a series 5 turbo RX7, it would give it enough power to turn on the dash lights, but nothing else, when all else failed, I used my G/F's barina. It jump started it no worries..!!!