I was using a battery off my tractor last year, and it was a year out of date. I could pull one tree (heavy leaner), and then have to take it back to the charger to charge while I rigged the next tree.
On the heavy red oak, I had a piece of 3/4" Stable Braid tied into a continuous loop through a primary fork. In the pull end of the loop, I had the big ISC block, and a piece of 9/16" Stable Braid running from a tree, through the block, and back to a porty, which I use to interface with the winch. This gave the winch a 2:1, which it desperately needed with the weak battery. I had two other lines in the tree, each hooked to one of the pullers. I had to inch it with the winch, get a couple of clicks on each puller, then repeat. A newer/stronger battery would have made it much easier for sure.