Magpul PTS Masada Railed Handguard ( RIS/RAS ) Battery Space???

[theskull]

I have a Masada and looking to fit the offial railed handguard onto this ( not fitting rails to original handguard )
but want to know the idea of battery space? as looks like ill be loosing space ?

if you know or have one can you please tell me how much space or whats the biggest type of lipo battery that will fit in side it?
i been told if i take of the QD barrell twister will give me more space too?