Sad to hear of your L39 loss Jack, but I really believe that we have the technology to (almost) totally avoid this sort of loss and probably all other power related losses, regardless of battery chemistry in use. I now use Weatronics 2.4 system in all my jets and this system gives me a huge range of highly useful facilities simply not available on any other radio as well as a DUAL RF link on 2.4

One of these features is the data logging of the system which is crashproof as its downlinked to an SD card in the Tx in real time. The system allows me to examine in great detail the performance of the batteries IN FLIGHT and you can plot the data on a graph or graphs, for example, voltage v current and relate that to the movement of any servo as servo positions are also logged. Its like a black box flight recorder and QAR rolled into one.

One great asset is that if you DO have a crash you have masses of REAL data to work with, no more guesswork or uncertainty AND the data to analyse your battery performance after every flight. Add to that the fact that the system will trigger an alarm on the Tx in real time if battery voltage falls below the level you have set on the Giga control software make this system absolutely brilliant and in my view, and I now have 9 of these receivers, the Weatronics, system leaves every other radio years behind what present technology can offer. I cannot imagine going back to any other system after seeing what the Wea can do.

Regards,

David.

PS As an aside you may recall I built a BVM F4 after seeing your dad's (give him my best wishes) "Screamin' Eagle" at Deland. Its still around and just been refurbished and now with an AMT NL Pegasus HPES which gives it a superb performance, even with three external tanks . I am now installing a Weatronics Micro 12 with 3 gyros in my Phantom. Out go the matchboxes, out goes the gyro (there are 3 in the receiver so it has damping on all 3 axes) and of course the external aerial is now gone. Combined with the Wea rx and the JR 12x tx with its switch assignability I have , for me at least, the perfect control system, and arguably, by far the safest.