I ordered a commercial wired power supply. Its on amazon for $14 with free prime delivery. I recieved it today (along with a battery finally) and wired it in parallel to the battery cable.
http://www.amazon.com/gp/product/B007O59Z7I
Took just a few seconds to solder a good connection and seems to work perfectly. The unit has over-current shutout and an led to indicate power. The reviews seems good but I guess I'll know in a few months if its a good solution.