Hi Remi,
if you are talking about the sled that Jerry made about 10 years ago, Alec Jarnagan had one for a while and Peter Vietro in NY still uses one. Uses 2 ab batts with a lot of available fore/aft adjustment. I hear Jim Bartel did the wiring so it's pretty solid I assume.
Yes that's the one. It looks like the batteries are hanging pretty low. I'm wondering whether or not this makes for a potentially long sled? Any thoughts?