Hello all. We have a very old Yale electric pallet jack. By what I can find online, I am assuming it is from the 70s/80s. There are no data tags on it whatsoever. Time, repainting and scrapes have removed anything that was there. Up untill a few months ago this thing function perfectly. Then the batteries died and we needed to replace them. The person who removed the batteries and the wiring is no longer with us and now we are not sure how to reconnect it safely. The batteries are (2) Everstart 24DC batteries. We are not sure if they should be wired in series or parallel. Any help would be greatly appreciated! I have more pic's if these do not help.