Hello.

I would like to ask for your help in solving the following problem:

I use the BETAFPV Cetus FPV Kit quadcopter.

When I turn on the quadcopter, the glasses show that the battery is fully charged, but as soon as I start flying, the battery charge drops sharply and the glasses show that the battery is low. The copter starts flashing red and lands.

Next, I turn off the battery and plug it into the voltage tester, the tester shows that the battery is charged. The situation is similar with all the batteries that I turn on.

When this problem appeared, I thought that there was a problem with the batteries and they needed to be changed. I bought new batteries, but the problem remained, so the problem is not in the batteries.

Have you ever had such cases? what can you recommend to solve it?

1. Charge up a battery and shove a multimeter in the xt30/bt2.0 or whatever connector it has. Is it full? So the problem is the charger that comes with it is crap. Buy a ViFly Whoopstor charger if you can afford one.
2. Take the canopy off and check all the wiring/soldering. Anything loose needs to be fixed.

I would have said batteries was the most likely problem. It may still be. If you are using the BetaFPV Lipos, get some GNB or Tattu packs and try those instead. The BetaFPV Lipos sag like crazy for some reason.