we had  3in here friday in  Indiana (our river got in our corn)   and we have  some beans left as well.    

Some of those beans  left in the field are from  Shatter loss.  Shatter loss happens  when the pods are  really dry  and the real or  knife creates enough  movement  to  knock  the beans out.  At times  we have had as much as  3bu/a  from shatter loss  in some types of beans.   And  the deer  do shell some as well.    Some times you just cant help that loss and its bad.

I dont think you can buy an open connection topped battery  for safety reasons.  NOW  I DID See  some  special built FORD batteries to put in  restored  9N and model A  fords.   Those had  those straps on them.

I do have  an old power supply I built  for  Engineering School to power  my   Digital  projects  but cant remember what actual voltage it was.  

and  Andy I    KNOW   I cant use  12v to charge that 8 LOL  i've seen the sparks fly  LOL   not good  REALLY  NOT GOOD!   
What we have done in the past  on  one machine  was just  charge it with a 6v...   believe it or not  We have had  luck  doing that  to keep  a battery from going  clear dead.. its better than  no charge I guess you would say <!-- s:) --><img src="{SMILIES_PATH}/icon_smile.gif" alt=":)" title="Smile" /><!-- s:) -->