My dilemma
 

ok I have been reading and reading and searching. my eyes are tired .. I have a brushless & esc im going to install soon but need to learn more on charging lipos so i dont burn my house down etc .. so that is why Im trying to get my car working with an old duratrax spike esc and my old twister brushed motor. my problem is mt flysky NB4+is telling me the FGr4s reciever is reporting low voltage.

the spike says its rated BEC is 5.6volts... which i think is what my controler was reporting as low.
the reciever is rated at 3.5-8.4V so why is it reporting low voltage when its within specs?
the battery is over 7 volts nicad andi hope this all makes sense.. i need ideas of where to start and what to look for as possible problems..
please and thanks in advance

Page 63 of the manual explains where and how to set the high and low voltage alarm.

of the NB4+? hmm ive been reading the book and just now looked and seen its the quick start guidwe ive been reading. ok thanks i will look for the full manual. my brain hurts from all the researcfh ive been doing. prob why i didnt notice the quick start guide. thanks again .