skyninja, i see your trying 45C discharge rating, have you tried anything lower or higher?
(i picked 45c because in my opinion, the mavic feels like a quad flying a 45c 3s battery) with your 9200mah of extra power, how long is your flight time? how dead are your extra batteries and your dji battery? have you (or anyone else) measured each individual cell of each battery?
anyone know, or is it safe to assume the mavic uses a 45c battery? anyone know what the C rating is on the mavic? anyone taken the lipo out of a spare mavic pro battery and mounted that as a external second battery, ideally that should give you at least 10 more minutes... in theory maybe more. im my experience both in hobby robotics and in my 20 years in RC, i found running batteries in parallel should always be done with identical batteries. mixing will cause the average voltage of the cells to drop but using identical batteries will cause them to drain equally, rather than bringing one cell down to as an example if you use a 3s 2000 Mah battery with a 3s 3000Mah battery in parallel the 2000 mah battery will read approx 2.90volts per cell and the higher amperage 3000mah battery at 3.2 volts /cell. 9.6 volt on a 3s battery is not so bad for the battery, but bringing one down to 8.7 volts is really hard on it. and that C rating is important also.. these multistar batteries i keep hearing about are 10-12C, that sounds really low, my racequads Need a minimum of 65c discharge rate or the battery only lasts a few flights. and flying at say 35c battery you can feel the battery sag durring punch out.
i would think you would want the secondary battery if not a identical mavic battery to be at least a faster discharge rate than the original battery and have a higher amperage to keep up with the current draw of the copter. to eliminate the average voltage drooping too low from one battery being too low, while the other have more voltage, i would think 4 1000Mah 45c batteries would be ideal if you cant use a dji battery for the secondary battery.
