ted:
put your toys in styrofoam box + thermostat no power from battery will be taken only a few minutes per hour = fridge effect
Hi, thanks for your suggestion.
That might work (will be able to tell when I get the temperature data back from the flight). The only problem is that the payload is imperfectly sealed as a fridge would be (two camera holes although the fitting is snug).
Working from peoples contributions from this post, I think I am going to go with the following:
3.7v heat pad (40 to 50 degrees of heat)
3.7v 18650 3000mAh battery (no voltage regulator required)
The isssue I have is no data about the current the heat pad draws but, assuming it's 700mA, that would give over an hour at 30% of the theoretical 100% (I think). More than enough formy flight as I suspect 30% is very conservative. Will test beforehand though!
Best wishes
Phil