Stop wrestling with individual vent caps and overfilling cells. The Flow-Rite Pro-Fill BG-U72V-BJ turns a tedious, corrosive chore into a single-point fill that takes seconds -- protecting your deep-cycle battery bank and extending service life in RV, golf cart, floor scrubber, and industrial applications.
The BG-U72V-BJ is engineered for 72-volt battery systems configured as either twelve 6V batteries or six 12V batteries wired in series. Each automatic shut-off valve threads directly into the existing vent-cap opening on your battery cells, replacing the stock caps entirely. Flexible interconnect tubing routes water from cell to cell across the entire bank, and a single fill port at one end lets you attach a hand pump, gravity-feed tank, or Flow-Rite water deionizer system and fill every cell simultaneously.
The valves use a float mechanism calibrated to the correct electrolyte level for flooded lead-acid cells. When a cell reaches the proper level, its valve closes automatically -- preventing overfill even if cells start at different levels. No more acid overflow, no more dry cells from underwatering, and no more stooping over a battery compartment with a turkey baster.
Float-controlled valves close at the correct electrolyte level in each cell, preventing overflow and dry plates.
Pre-cut flexible tubing manifolds connect all cells in the bank for true single-point filling without kinking.
Valves are compatible with most standard flooded lead-acid deep-cycle battery cell openings across major brands.
Sized and supplied for a full 72V bank in either common configuration -- no extra parts, no cutting to fit.
Flooded lead-acid deep-cycle batteries lose water during every charge cycle through electrolysis. Consistently low water exposes the lead plates, causing irreversible sulfation and early failure. Overfilling pushes diluted acid out of the vents, corroding terminals and battery trays. A properly installed Pro-Fill system eliminates both failure modes, often doubling practical battery service life compared to inconsistent manual watering.
Installation requires no special tools beyond a screwdriver and a sharp blade for trimming tubing if needed. The process:
The Pro-Fill BG-U72V-BJ is designed for flooded (wet cell) lead-acid deep-cycle batteries only. It is not compatible with AGM, gel, or lithium battery types, which are sealed and require no water addition. Common compatible applications include golf cart battery banks, RV house battery banks (flooded 6V golf cart cells such as Trojan T-105, US Battery US-2200, Crown CR-235, and similar), electric floor scrubbers, aerial work platforms, and industrial electric vehicles running on 72V flooded battery systems.
For the cleanest water source, pair this system with a Flow-Rite battery water deionizer or a compatible hand pump / gravity feed bottle. These accessories connect directly to the BG-U72V-BJ fill port fitting. Using deionized water removes chlorine, minerals, and contaminants that shorten battery life beyond what distilled water alone provides.