Hi Tim,
Thanks for the report. Maybe we will get to see ski photos in Feb., when the snow gets really deep?
I agree that we have to be careful in drawing too many conclusions from your results, because of the many variables.
1. As you said, one issue is that the batteries may be near their "end of life" stage (which in the battery world is universally understood to be when the battery will only recharge to 80% of it's original capacity).
2. The other issue is the one William eluded too: the lack of headroom did not give you anything left over to make up for the cooling of the battery.
3. The fact that they are inexpensive batteries may or may not be a factor. If you put a lot of flights on each of these (>50) then this may be an age issue.
I fly mostly ERC, and at our E field many sport flyers use the batteries you are using. They are so inexpensive that even though they always have a shorter lifespan than our ThunderPower, and Hyperion batteries, they still may end up costing a little less because you can buy 2 or 3 of them as they wear out. This ratio is changing as our prices are coming down. But even so, I feel much better knowing that my batteries are putting out full power, at the C rating on the label and I can depend on them not failing at the top of the clover, or in ERC3D. ...... The inexpensive batteries still seem to work OK for many of the sport flyers. They don't stress them, and when they fail (some in 10 flights some in >50) it almost never is a problem, in sport ERC they can almost always land safely with full control. Not so in E-CLPA!
4. With the above said, it looks like the cold had an impact! I agree that using the larger 5S packs is a good solution to make up for the power loss due to cold.
5. I'm glad you mentioned the greater amount of drag that our profile models produce. I notice it with my E-P-40. I hope more people realize that they have to have more battery mAh than with a similar size full fuse. plane.
6. There are a number of ways to solve this puzzle:
1. Bring your plane and these batteries out here and fly it. It was 76 f yesterday. You can leave any skis at home. This will give us firm scientific data for comparison!
2. Get some 4,000 mAh batteries (same brand) and fly them to see if it was an "overhead" issue.
3. Use some new fresh batteries, same brand. Then use some TP/Hy batteries.
4. You could try an APC 13 x 6.5 prop. This will give you faster lap times, probably heat up your battery (pulling more Watts). If you try this, you may want to plan on a possible short flight. ?
I like #1 the best.
Thanks again for your experiment and data. It will be interesting to see how others make out in cold WX E-flying this winter. And thank you for bringing us so many beautiful E-CLPA planes. You are an inspiration to us all!
Regards,