Allo Isolator - problems

I’ve just bought ALLO ISOLATOR for my RPI3, Kali and Piano 2.1.I’ve also bought LIFEPO4 battery 6,6v (2S).
I put together RPI then ISOLATOR (jumpers for SLAVE), then KALI (I removed feeding jumper) then piano.
I conect battery to ISOLATOR THEN to RPI separate 5,1v from power suply.
AND NOTHIG - sure RPI starts thts all, Maybe i’m doing something wrong.