I have been using the Opti-Power Back Up for about nine months. I used to run two 2s 450mah packs run through Tech-Aero Regulators operating in parallel for redundancy. I reconfigured to incorporate the Opti-Power Back Up. I now run the Tech Aero Regulators in Parallel off a single main pack's balance lead. (Must be the first pack in the series) To that I added the Opti-power Back up. The Back Up battery trickle charges off of the main pack so it remains charged and ready to take over if needed. An optional 3 LED strobe indicates when it's armed and continuously flashes if main power is lost. I flew half a sequence with the main pack supplying power, landed - turned off both regulator switches and flew the second half of the sequence on the Opto-Power Back Up. The Flashing LED was clearly visible from the ground and gave me confidence that I'd know if I lost main power. I also looked at the Scorpion Back Up. It essentially works the same except it beeps so there no indication in the air of a problem. I have switched all of my electrics, planes and helicopters, to this configuration and haven't had a single issue.

The one lesson learned is to disconnect the battery from the circuit board as it will slowly discharge the battery if left connect for extended periods. If I flew every day I'd just leave it connected.

James