Yes, I had to extend the cables slightly. I used cables like this https://www.amazon.com/Spartan-Power-Battery-America-Terminals/dp/B07L46N3WB/ref=asc_df_B07L46N3WB/?tag=hyprod-20&linkCode=df0&hvadid=309770211034&hvpos=1o5&hvnetw=g&hvrand=9690146978857809537&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031933&hvtargid=pla-595118877563&psc=1 and simply cut it to length, connected the cut end to the terminals and bolted the other end to the existing cables. You can kind of see it on the negative side. Altogether, I probably only added about 1 inch of cable.I am looking to put a 31M battery in. You have a lot going on there. Did you have to do anything for the battery cables?