Originally Posted by xcntrk

Doesn’t the latest castle-link software only allow a max of 12v for cutoff (4s 14.8v)? I don’t see in the menu where you’d specify a 15v cutoff. Maybe if you totally disable the internal LVC and run an external one it may sync up. Easy way to try is to “disable” the LVC and plug in the 5s pack to see if it engages (obviously you cant run the 5s pack without LVC protection).