Ni Knight; If you mean like 12 v, Schmidt is working on such a model which comes with slightly more drag than their 6 v model.
I must say about Schmidt dynohub it seems strong. I took it on a road ride to day but went off road for as long time as on (thank god for a multi capable bike). Feels like a strong hub which hopfully will hold for 50 000 miles or something before needing service.
Anders K