The 3rd, wooden rack was originally meant to be filled with batteries. 4x group 27 deep cycle per shelf in 48v config with rectifiers and inverters in the other rack, but never happened. I actually plan to move the batteries out of there. Maintenance is kind of a pain since I can't access the fill holes so need to disconnect each time. Probably going to upgrade the solar batteries in my shed then move the shed batteries to a separate box in the crawlspace. Easier to access the tops with that setup. My end goal is to run all of this mostly on solar. I do need to setup proper automation for that, such as an automatic transfer switch to go back to hydro if the solar batteries get low. I think what I'll probably do is set it up to run on solar during production hours only so that the batteries can stay full overnight.