You have several different things going on in my opinion. It is my belief that after a couple of dozen flights the E-Flite packs are done, with careful flying/charging strategies you can extend that life span some, but it is a basic engineering problem. I do not have a 120sr, but I do have an mCPX as well as many other planes and helis. Helis need constant voltage and amperage. So how a C rate is listed is a big deal(constant C or burst C), as is the size of the pack overall. I think if you hooked up a watt meter you would see that you are running that battery at 10+C continuously. A huge clue was looking at the motor and battery connectors. Those are mini-JST's rated at 7A, although they are good for 3 times that . Putting them on a single cell lipo, much less one that small, tells me that the constant draw was damaging the JST-XH plug. That is the one on your Extra. A little looking around has shown me that the larger version of the JST-XH that is on the mCPX still may not be enough for the draw. The mQX has the same battery configuration.

The power system on the Extra has been being tweaked for 6 years starting with the Minium line of Micros. And is far more established I tend to store my single cells from charged to recharge before the next use if it is over a few days. And the only ones that have just given up soon have been the HH packs and the early nanotech 130's. I have Nano tech 160's, Hyperion 180's, and Hyperion 250's. All of them are superior to the Horizon products.

I hope I was not to, well not to much. I am working on a battery issue that is due to an aircraft issue so all of this is what my brain is working on. My problem is why did making everything smoother, better adjusted etc cost me so much battery unhappiness in my EXI 450[>:]

And just because I can, here is the video of the offending test flight Have a great Week End All!!

[youtube]http://www.youtube.com/watch?v=4Zx0gUf_gKQ&list=UUT-tXf901oScQfbdRnsQY8w&index=1&feature=plcp[/youtube]