Here is a way to extend the lcd display on the BMS-24.
Not approved buy Chargery. Seems to work ok.
Starting from opening box to connecting to db-25 cable.
Similar boards available using rj-45/cat-5 cables. Smaller ends for fishing thru holes.
Out of order I see, but you get the “picture”. 
90 degree plugs available.
Custom built or pcb only for $10 each.