Battery is usually not a worry as it last longer than our legs. It higly depends on the winch use (length and speed of the runs, foil size, board size, rider weight...) but let you for sure enjoy at least two 3h sessions with friends (usually 5 or 6 sessions).
A single rope loop at the back of the winch allows to anchor it on any fixed point. The fixed point can be a bag full of sand on the beach, a stake of around 20cm on the ground, a rope loop around a rock or any existing fixed point.
For now, you have to use it with at least one friend. But a remote is in development.
Full charge takes around 4h30. But in normal use, we rarely use the full capacity of the battery and charging time is usually around and lower than an hour.
The WindUP winch is not made for wakeboarding, it doesn't allow deep waterstart with very low volume board. But it can waterstart most of surfoil depending on their voulume, the foil size, rider weight and waterstart technique. We made a simulation tool that gives an indication wheither waterstart is possible or not with your gear. Check it out below.
This tool gives an indication but is not a warranty as the ability to waterstart higly depends on the level, the waterstart technique and foils and board specificites.
The tool above indicate the possibiliy of waterstart either kneeling or standing on the board with or without sinking the board dependng on its volume.
It is possible to waterstart with even smaller foils/board (like kitefoil boards) by doing a surf take off once at speed.