Stop pulling individual caps and guessing water levels. The Flow-Rite Pro-Fill system replaces all vent caps on your six 6V batteries with automatic shut-off valves, then connects them with pre-fitted tubing so you can fill every cell in one controlled operation -- no overfilling, no acid spills, no kneeling over a hot battery bank.
Whether you run a standard RV house bank, a golf cart pack, or a solar storage array, maintaining proper electrolyte levels is one of the most important -- and most neglected -- aspects of deep-cycle battery care. Underwatering kills plates. Overfilling dilutes electrolyte and causes corrosive boilover. The Flow-Rite Pro-Fill system takes the guesswork out by automatically stopping flow the moment each cell reaches the correct fill level.
The BG-U36V-1A kit is engineered specifically for six 6V deep-cycle batteries arranged with 2.7-inch center-to-center cell spacing -- a common configuration in RV, golf cart, and off-grid solar applications. The tubing is pre-measured and the valves drop straight in, so installation is a one-time setup with no special tools.
Float-controlled valves stop water flow automatically when each cell hits the correct level. No manual monitoring needed.
Tubing lengths are matched to standard 2.7-inch cell-to-cell spacing on 6V deep-cycle batteries for a clean, secure fit.
Connect a single hose or hand pump to the system inlet and all 18 cells fill simultaneously -- finish a full bank in under a minute.
Valves thread directly into standard 6V battery vent cap openings. No drilling, no permanent battery modification.
Each valve contains a float mechanism calibrated to the correct electrolyte level for deep-cycle batteries. Water flows freely until the float rises and seats the valve -- stopping flow at the precise level every time, regardless of how hard you squeeze the supply bulb or how high the line pressure is.
Installation requires no special tools and does not permanently alter the batteries. The general process is:
This kit uses Flow-Rite's standard quick-connect fill port. It is compatible with the Flow-Rite EZ-Fill hand pump, the Flow-Rite gravity-feed adapter, and standard garden hose adapters sold separately. The fill port accepts Flow-Rite's bayonet-style quick-connect nozzle.
This system is designed exclusively for flooded (wet cell) lead-acid batteries that require periodic water addition. Do not attempt to install on sealed AGM, gel cell, or VRLA batteries -- those batteries have no accessible vent cells and do not require watering.