Oh, I have a bad feeling about this one. As I think we all know, MNKE batteries are orange and have 'MNKE' written on them. The only wholesalers I found when I Googled 
were these guys.
These specs are stated on both Hoosiers and the wholesaler sites:
Maximum Continuous Charging Current      6.5 A    
Maximum continuous discharging current   25 A
Well, the maximum charge current of 6.5 A is 
way too high and quite dangerous to try. That mistake puts the discharge current in doubt for me. I would not touch these batteries with the proverbial ten foot pole.