I'm going to keep that extra 12v battery. I finally got my bike up to 35 mph today even with 15 mph wind. It just took a very long time and about 2000 watts peak and 44 amp peak to do it. I had to hold the throttle down for a long time. I just wanted to see if it was capable of it and it is. I found a way to strap the extra battery on the top of my topeak bag.