I just got a new battery. I charged it and it didn't want to takeoff. And i got error: Unable to takeoff. I verified the battery settings, and i saw the voltage was 9.48 and the cells 4.74 each. After i flew it, at 20% the battery started draining very fast and it entered in forced landing and shut off.

Hi, djiuser_elmIyQiglT87. Thank you for reaching out. The "Unable to Take Off” message is displayed on the app if the environment is poorly-lit (with an illumination less than 10 lux) and the GPS signals are weak. If the GPS signal is strong, the aircraft is able to take off and default restrictions are not triggered. The forced landing might be caused by the Low Battery RTH. Low Battery RTH is triggered when the Intelligent Flight Battery is depleted to the point that the safe return of the aircraft may be affected. Return home or land the aircraft immediately when prompted.