Stop crawling over your battery bank with a funnel and a flashlight. The Pro-Fill BG-U36V-8J replaces all your vent caps with automatic shut-off valves, links them with flexible manifold tubing, and lets you water an entire 36V battery bank through a single fill point -- in seconds, without overfilling a single cell.
Flooded lead-acid batteries -- whether 6V golf cart style or 12V deep-cycle -- need regular watering to stay healthy. Under-watering shortens battery life; overfilling causes acid spills, corrosion, and potential injury. The Flow-Rite Pro-Fill system solves both problems with float-controlled shut-off valves that stop water flow automatically the moment each cell reaches the correct level.
The BG-U36V-8J is sized specifically for a 36V battery bank: it accommodates (6) 6V batteries or (3) 12V batteries, covering the most common configurations in golf carts, RV house banks, floor scrubbers, and industrial equipment running at 36 volts.
Float-controlled valves stop flow at the correct electrolyte level -- no guessing, no overfill.
Connect your water source once and all cells fill simultaneously, cutting service time dramatically.
128-series flexible manifold routes between batteries regardless of terminal or cap orientation.
Replaces standard vent caps on most flooded lead-acid batteries without drilling or modification.
Each automatic shut-off valve threads directly into the battery cell opening, replacing the existing vent cap. All valves in the bank are then connected in series using the included flexible manifold tubing. A single fill coupling -- positioned at an accessible point on the battery bank -- is the only connection point you need. Attach a water source (hand pump, gravity bottle, or electric pump sold separately), squeeze, and walk away. Each valve closes independently when its cell is full.
There is no electrical connection required. The valves are entirely mechanical, relying on a float and spring to stop water at the correct level every time.
The BG-U36V-8J is designed around two common 36V bank layouts:
The "Universal" designation refers to valve and tubing compatibility across most standard flooded lead-acid cell openings. This system does not apply to sealed AGM, gel, or lithium batteries -- those types do not require watering and have no fill ports.
Flow-Rite uses a series designation system for their tubing. The "128" manifold used in this kit is a flexible-profile tubing that routes between adjacent batteries, bending to accommodate varying battery heights, top-post spacing, and side-by-side or end-to-end bank layouts. It is pre-cut and fitted with push-in connectors that attach to each valve body without tools.
No special tools are required for a standard installation. The general process is:
Installation typically takes 20-40 minutes on a clean, accessible battery bank. Ensure batteries are fully charged before the first watering after installation, as is standard practice for flooded lead-acid maintenance.
The BG-U36V-8J kit includes the valves, manifold, and fill coupling, but the water delivery device is sold separately. Flow-Rite offers compatible hand pumps and electric pump assemblies designed to connect directly to the Pro-Fill coupling. Using a dedicated pump keeps the fill process hands-free and contained.