Vintage Simmons Drums (UK) Users Group

I need to know the exact type of Ni-cad battery (volts, milliamps, 
etc) to use and how does it draw power to recharge.  Let me know if 
this is what your battery looks like: it is wrapped in white plastic 
with a white plastic cap.  There are 2 posts that slot into the PCB 
and then another arm that comes out of the PCB that extends over the 
top of the battery.  I had to dig under the arm to free it from the 
battery. I also had to pry the 2 posts from the PCB (I'm afraid that 
I may have left a little piece of the post in the PCB).  The battery 
itself is made up of 2 separate cells that are soldered together.  
Does this sound right?  

Also, maybe somebody can help with THIS problem:  When I turn the 
unit on, all of the drums start playing by themselves simultaneously 
as fast as they can go.  I've taken the battery out and it is still 
happening.  There is nothing I've found that will stop this.  At 
this point, the unit is still great for MIDI but I can't use the 
internal sounds at all.  Also, is it right that the unit really 
heats up after being on for 1/2 hour?  Any help would be appreciated.

Thanks,
Jeff