I emailed DC and there customer services have confirmed that the ANR moduals are happy up to 12V and start melting at 15Volts.
Now if these nice people who do the ANR upgrades can produce a DC rechargable bat pack of 9-12 volts with an internal charging circuit which takes a car charger or any other 14V dc supply with about 600MAh or more capacity. I for one would be interested.