Stop pulling individual vent caps and guessing at water levels. The Flow-Rite Pro-Fill system links all cells in your two-battery 6V bank with a single-point fill line, auto-shutoff valves, and 127-degree flex manifolds so every cell stops at exactly the right level -- every time.
Deep-cycle 6V batteries -- the workhorse of RV house banks, golf carts, and solar storage systems -- demand regular watering to hold capacity and extend service life. Doing it cell-by-cell with a squeeze bottle is slow, easy to get wrong, and risks acid burns from splashing electrolyte. The Flow-Rite BG-U12V-7A Pro-Fill system replaces all existing vent caps on two 6V batteries with automatic shut-off valves, connects them with flexible tubing, and lets you fill the entire bank by pressing a single hose fitting -- in under 60 seconds.
The 127-degree flex manifolds are the key to this kit's "universal" designation. They compensate for the varying cap-to-cap angles found on different 6V battery brands and case styles without requiring any drilling, cutting, or custom hardware. If your batteries have standard threaded vent openings, this kit fits.
Float-valve design stops water flow the instant each cell reaches the correct electrolyte level. No overfill, no acid overflow.
Angled connectors bridge cell openings at varying pitch without forcing hose into sharp bends that restrict flow or crack tubing.
Replacement valves thread into standard 6V deep-cycle vent openings. Compatible with most major battery brands out of the box.
Valves, interconnect tubing, 127 flex manifolds, and a fill port included. One purchase, one installation, done.
A standard 6V deep-cycle battery has three cells, each needing individual attention. Two batteries in series (for a 12V house bank) means six fill points to manage manually. The Pro-Fill system reduces that to one fill point and eliminates the guesswork from electrolyte levels entirely -- critical for flooded lead-acid batteries where dry cells shorten life dramatically.
Installation requires no drilling and no special tools. The process is straightforward:
Most RV owners complete the install in 20 to 30 minutes. The system is compatible with Flow-Rite's EZ-Fill hand pump and Pro-Fill QD quick-disconnect hose extensions for even more convenience.
This kit uses standard Flow-Rite Pro-Fill quick-disconnect fittings at the fill port. It pairs directly with the Flow-Rite EZ-Fill hand pump (sold separately) and any Pro-Fill extension hose. If you already own a Pro-Fill pump from another battery kit, the same pump works here.