I had helicopters for about 40 years and decided about 10 years ago to sell them and just fly drones in future. Already around 2012 I flew a 450 size helicopter via FPV, stabilised by a DJI Wookong H (which was not really good).
Three weeks ago...
New batteries have arrived, charged and ready to go. In the pic the stock 5000mah battery is being discharged to storage level. The new batteries fit perfectly and are a sweet upgrade. She hasn't even flown yet! Saturday....