Different motors, different batteries.
I built another Tiny Trainer. The first glider wing 3 channel was getting shabby so I built another one. This time I used a BE1806 2300KV motor, 6030 propeller and 1000 mAh 2s battery. All very similar to the recommended power pack. AUW is 12 oz. I found I couldn't run the battery down to where the alarm sounded without it becoming hard for me to control. There wasn't enough thrust to keep it moving without stalling. It was sluggish. I broke my last 6030 prop on a sloppy landing after it tip stalled too close to the earth.
So I put on the only small prop I had, a 5050. Then I put in the new 3s battery I just got. What a difference! It's a different airplane with the 3s. I expected it to be a bit faster but with a smaller prop I didn't expect this kind of speed. I love it. Half throttle is like the 2s was at full and a fresh charge. It is much easier to fly when there's power to spare.
The four channel sport wing Tiny Trainer has a 2212 1400KV motor, 30A ESC and swings a 8060 prop. With a 2s battery, AUW is almost 15 oz because the power pack is about twice the weight of the 3 channel airplane power pack and there are two additional servos. With the power to use a bigger propeller the performance with a 2s battery is the same as the smaller motor with a 3s. The extra weight makes the airplane easier to handle when there's wind. I had a 9" prop on it for a while and it had no problems with over heating any of the components.
So far I'm beginning to think the extra weight of a larger motor and a big prop is a better way to go. You may have to add weight to the tail but with the extra available power it won't make a difference. I like not having to run full throttle all the time. I can't wait to see what the 3s battery does in the 4 channel sport wing Tiny Trainer.
I'm going to play around with the 1806 motor on the 3 channel some more and see what it's like with a 6" prop and 3s battery. I have a 2212 1000KV motor and I think it's going to replace the little 1806. I love these Tiny Trainers and I'm learning a lot from building and flying them.
Jon