I heard the original mod had also batteries (not shure why it was removed maybe op) how about you make a return of that equip?

Original mod in the last version supported only equipment from group "companion".
During some testing a have added also group "armor" which contains batteries. In last version I have restored original behavior like original grid size 10x2 and restriction only on companion equipment.

I am not sure what is the benefit of battery, when you have availeble the companion reactor from start

well... a battery have a much lager output tham a reactor if you check the energy shield it need 6MW to recharge at max speed that means 6 reactors