Discussion about the Korg PolySix synthesizer

Hi all,

I' m discussing with a friend about the Ni-Cd battery charge ,
expecially on the charge time .
 I 've replaced with a new Ni-Cd but not positioning it at the original
place, but moving it near the Power Transformer plugging  the battery at

the  KLM-367 board with a bipolar cable.(this to avoid eventually
leakage problems and  and having original inside P6) .
The question is :
How many hours I have to leave powered on  Polysix in order to have a
good primary  charge?

thanks in advance .

Marco