Discussion about the Korg PolySix synthesizer

hello, i am new here and new to owning a polysix.  I bought it in as is condition which is 
ok with me because i think the polysix rules, but now its time to get it working 100%.
first I need a battery.  I am looking for somewhere to buy one, model, make, any info.
next, how about anyone knowing anything on prices on repairs.  just an estimate on 
battery replacement and common maintenance. Any help on any of these questions would 
be greatly appreciated.