Do i need a extra battery and a cap for my jl1000.1 v2?

I have a jl 1000.1 and two jl w6s well im running them off my stock battery but when i hook the subs up to my amp the amp barely pushes them i asked a jl dealer if my amp was blown or faulty and he told me that if my amp turned on it was fine and that those amps require a **** load of power so i needed an extra battery and a cap well im here because i need a little more advice thanks.....