New battery install

Hello, in my,logo 550 I have a new battery Hacker EcoX 6S 4500 to replace a 5000 EcoX 6S.
Everything is the same. I created a new battery in the list, select it manually and when I start the motor I only get about 350 rpm. Somehow I cannot increase the rpm to flying speed. I plug in the old battery and it works fine the rpm is correct. The only difference is that the 4500 is a 20C vs. 30C. Is it simply that this battery is completely insufficient power to start the scorpion 4025-1100? YGE regler is handled through vstabi.
Thanks, Dennis

Check the battery- voltage.

Stephan

So, later after dinner, checked again. All appears to be working correctly with the new batteries. Voltage of no load with batt checker was 24,84 and 24,92V. UI Sensor reported 25v available. After startup of a few seconds the UI reports I=4.25 A, U=24,7V, I peak =16,02A, Cap =31mAh.
This with 34 seconds run time and RPM =1431. (no blades of course).
I have the idea that since one of my 5cell batts actually has a 0v reading. It did not release that figure when I deleted the battery from the list. So, now after turning the complete system off for a hour or more it is ok. We will see this weekend when I get this beast to the field to try again.
Thank§