Stop guessing on water levels and eliminate acid spills. The BG-U48V-1K Pro-Fill kit converts four 12V Crown flooded lead-acid batteries to a single-point watering system -- fill all cells in one connection, and the automatic shut-off valves cut flow the instant each cell reaches the correct level.
Maintaining flooded lead-acid batteries in an RV, solar bank, or golf cart means checking and topping off every individual cell -- typically 12 to 24 filler holes per bank. One missed cell shortens battery life; one overfilled cell causes corrosion and electrolyte loss. The Flow-Rite Pro-Fill system solves both problems.
The BG-U48V-1K is engineered specifically for banks built from four 12V Crown flooded batteries (a common 48V configuration). Each automatic shut-off valve replaces the existing vent cap on every cell. Pre-cut, color-coded tubing links all valves in a series circuit, and a single fill port gives you one place to connect your water source. When a cell is full, its valve closes -- automatically, with no float adjustment required.
Float-actuated valves close at the correct electrolyte level -- no manual gauging, no overfill risk.
One quick-connect port services the entire 4-battery bank in under a minute.
Valves are sized and threaded to fit Crown flooded 12V battery vent ports directly.
Interconnecting tubing ships pre-cut for a 4-battery series layout -- no measuring or cutting required.
The BG-U48V-1K ships as a complete kit. Every component needed to convert a 4-battery Crown bank is in the box:
Flooded lead-acid batteries lose water through the electrolysis and evaporation that occurs during every charge cycle. Letting plates become exposed accelerates sulfation -- the leading cause of premature battery failure. Consistent, correctly leveled watering is one of the highest-ROI maintenance habits for any battery bank. The Pro-Fill system makes it fast enough that it actually gets done.
Installation is a direct replacement process: remove each existing vent cap, thread in the Pro-Fill shut-off valve, route the pre-cut tubing between valves in the order shown on the included diagram, and connect the fill port. No drilling, no battery modification. Most installers complete a 4-battery bank in 20 to 30 minutes on the first attempt.
Use distilled or deionized water only. Tap water minerals deposit on plates and degrade electrolyte chemistry over time. Flow-Rite and Crown both specify distilled water for flooded battery maintenance. A dedicated Pro-Fill hand pump or gravity-feed jug connected to the fill port makes the process even faster.
The BG-U48V-1K fill port is compatible with standard Flow-Rite Pro-Fill hand pumps and gravity-feed jugs (sold separately). Using a dedicated pump with a quick-connect nozzle reduces fill time to under 60 seconds for the full bank and eliminates any contact with electrolyte.