DIY external dslr battery, is it safe?

This video is a proof that Canon DR-E6 coupler does not have dc converter built-in. So please use it at own risk. 9 volts seems okay for Canon 6D camera but 12 volts might be dangerous, so I didn't try. The overall conclusion is that the expensive Canon DR-E6 dc coupler does not have DC converter built in.
"modified adapter" : means I replaced the original canon pin with regular 3.5mm female pin and also replaced one end of Anker battery cable with 3.5mm male pin. So they now fits perfectly. (Please check and make sure of polarity + to + / - to - ) Bonus point: Don't throw the original pins and cables. While cutting keep at least 15cm of wire. Buy extra 3.5 male/female pin pair and attached it to cut ends. You might need original wires in future.
Cheers
Canon Product: DR-E6 DC coupler
AnkerProduct: Anker® 2nd Gen Astro Pro2 20000mAh
www.ianker.com/...