I'm not a DA guy, just try to read up on the posts about them since I may give them a try one of these days, but IIRC there are some voltage input considerations for DA. A fully charged 6 volt Ni-Mh can put out more than 6 volts so you may want to verify what the module will take for input voltage.

I know that the older style modules used on my ZDZ's were restricted on input voltage, but the new 100 I have can run off unregulated Lithiums with an input voltage range up to 9 volts.

Maybe you've already checked that, or some of the DA guys will check in on the voltage input question?

edit info:

Looks like some others who know more about it than me checked in while I was typing...