I know the vast majority of members use DJI drones, and very nice they are too. But most of the time I’ve been happy with my Fimi A3, partly because of it’s built in controller screen which I managed to modify for increased brightness and partly because it flies so nicely. But as you may know, that drone has been around for a long time now and new original 2000 mAh batteries are virtually impossible to get. Even those still available are some years old so normal flight time is very limited.
I tried a couple of solutions - I found one battery which would fit easily inside the drone, and another which was problematic. But I have eventually succumbed to strapping one underneath as has been done by many others. The battery I chose is 2900 mAh and lighter than most - an Overlander 2900mAh 11.1V 3S 35C Supersport Pro. It gives me a safe flight time of 20 minutes leaving the battery with still almost 11 volts after recovery.
I should make it clear that this includes a few minutes of flying after the dreaded ‘landing automatically’ sequence kicks in at around 10.7 volts, most annoying when the battery can safely be run to below 10 volts. Fortunately a while ago I found that by then putting the drone in ‘return to home’ mode it can be flown normally for some time. It won’t hover, if that is attempted it will continue to return home, but won’t descend by itself until it has returned to above the home position. You just have to keep an eye on the voltage and land before it drops too far.
BUT here is the rub! This Summer I invested in an add on for my A3. The drone already includes a servo control system which with suitable hardware can be used for a number of purposes. I located a drop system which uses this feature and it works beautifully, so I tried it out this year to take my fishing lure out 100 metres, much further than I can cast, in an attempt to catch some mackerel when on holiday - I use a single spinner system for sport, (I would of course intend to eat the catch, one of the finest fish when fresh!) Alas there were no fish around, but the system worked well except for the need to frequently change original batteries, and the location of the drop system means that I can’t use an underslung battery.
However, today I experimented with the battery on top of the drone and the drop system underneath. I was concerned that the drone would be unbalanced and unstable, but the gyro coped perfectly - rapid reverses of direction both in line and sideways were handled without any problem. Mackerel watch out 
So here for anyone who just might be interested are photos.
Cheers, Peter
