Stop lifting vent caps one by one. The Pro-Fill system connects all cells with precision tubing and automatic shut-off valves, so a single fill point waters your entire 36V battery bank simultaneously -- no overfilling, no acid spills, no guesswork.
Flooded lead-acid batteries require regular watering to stay healthy -- but the process of removing individual vent caps, checking levels, and hand-filling every cell is time-consuming and easy to do wrong. The Flow-Rite Pro-Fill BG-U36V-4A eliminates that hassle with a permanently installed system of automatic shut-off valves and interconnecting tubing.
This kit is the non-standard spacing / no-manifold variant, designed for 36V battery configurations where batteries are spaced further apart or arranged in ways that standard pre-assembled manifold kits cannot reach. The tubing runs directly from valve to valve without a rigid manifold bar, giving you the flexibility to route around obstacles in your battery compartment.
Valves stop water flow the moment each cell reaches the correct electrolyte level -- no overfilling possible.
Flexible tubing routing works where rigid manifold kits cannot -- fits irregular battery layouts and wider-spaced banks.
Individual valve-to-valve tubing runs eliminate the need for a shared manifold bar, simplifying fitment in tight or custom bays.
Sized for a full 36V flooded lead-acid bank -- typical in golf carts, industrial equipment, and large RV house banks.
Each automatic shut-off valve replaces the existing vent cap on a battery cell. The valves are then interconnected with small-diameter tubing. When you connect a water source (deionized or distilled water supply) to the single fill port, water flows simultaneously through all connected cells. As each cell reaches its proper level, its valve automatically closes. Filling the entire bank takes seconds instead of minutes.
Because the system is permanently installed, you never need to touch individual vent caps again during normal maintenance. This is especially valuable in applications where batteries are hard to access -- under seats, in enclosed bays, or stacked in deep enclosures.
The BG-U36V-4A kit contains everything needed to water a 36V battery bank with non-standard cell spacing and no manifolds:
Flow-Rite offers two Pro-Fill kit families for 36V systems: standard-spacing kits (which use a rigid manifold to span cells on a single battery) and non-standard / no-manifold kits like this one (BG-U36V-4A). Choose this kit when your batteries are not the common golf-cart 6V footprint, when batteries are mounted in separate locations, or when the gap between cells is wider than a standard manifold bar spans. If you are unsure, measure the center-to-center distance between fill ports on your batteries before ordering.
The Pro-Fill system is designed exclusively for flooded (wet cell) lead-acid batteries. It is NOT compatible with AGM, gel, sealed (VRLA), or lithium batteries. Those battery types are maintenance-free and do not have fill ports. Attempting to install fill valves on sealed batteries will void the battery warranty and may cause damage.
The BG-U36V-4A kit includes the valves and tubing but does not include a water supply pump. Flow-Rite offers compatible hand pumps and gravity-feed bottles designed to connect directly to the Pro-Fill single fill point. Search for Flow-Rite Pro-Fill hand pumps or ask about bundle options.