Something all you car audio guys will get a kick out of!
A big 3D printed mod build using Dual 2.7v 3000 farad Maxwell Supercapacitors in series for 5.4v 1500F. Thanks to the wonders of graphene, this bad boy is able to store more then 300 seconds of 60 watt pulls (0.3ohm coil). But more importantly, using just a mere 300 Watt 5v power supply, it only takes 15 minutes to charge bag up to full capacity! :)