I purchased a EV-Peak dual battery charger from Carolina Dronz last month and finally had a chance to try out. Nice option to charge 2 batteries at once and display shows each cells charge rate.Charges in half the time and apparently did a better job then the factory charger. Both batteries lasted for 20-21 min. verses 17-18 with the factory charger. We had 20 mph. winds so she was working harder than usual. I usually dont fly in these conditions but every weekend here in Md wind or rain has me grounded. Great charger only lacking storage or discharge option. What I did once batteries were cooled down charged to 51% 3.82 volts per cell for storage.with this charger took 15 minutes. One thing i must say Q500 handled great in the wind compensated well she was getting pushed around.