400mAh 2S 7.4V 30C LiPo Battery with JST Plug for Micro FPV Racing Drone | Crazepony 2PCS 2S Lipo Battery Pack for Quadcopter

I have used these in my RC plane and they work well. They are lasting as long as expected based on the stated mah. I'll buy more.

I'm using these on small custom-built RC airplanes and they've been working fine. No noticeable degradation so far, no unreasonable heating, I haven't noticed any voltage sag at full throttle.

These were the perfect match for my rc plane and even had more mah which gave me longer flights and they seem to have more punch also with a better c rating however....they don't seem to want to charge to the 4.2 limit I have only been able to get them to 4.18 but they are great batteries so far I have only cycled them 3 times so maybe once broken in they will reach the 4.2

Good product

Excellent small battery. They have worked so well and fit my tight space, I have purchased another pair.

These are the perfect size for the project I just finished. BMJR Sniffer park flyer.

As advertised

Edit: They seem to be working on the below described problem so I will give them another star. When I see that it's fixed I will add another. The wires on the JST balance charging plug are way too short. You might be able to barely get a balance plug protector on there, but I doubt it. Even if you did, it would be so tight that it wouldn't move at all. Since the length of the wires is less than the width of my fingers, I'm pretty sure that the wires will get ripped out of the plug very soon.