Stop crawling around your battery bay with a squeeze bottle and a flashlight. The Flow-Rite Pro-Fill BG-U36V-7A replaces every vent cap on your six 6V Trojan Plus deep-cycle batteries with automatic shut-off valves, links them all with 127 flex manifolds, and lets you fill the entire bank through a single quick-connect port -- in under a minute, every cell filled to exactly the right level.
Deep-cycle batteries in RV house banks, solar storage setups, and golf cart conversions need regular watering to stay healthy -- but checking and topping six 6V batteries individually means wrestling with tight battery compartments, acid exposure, and the real risk of overfilling. The Flow-Rite Pro-Fill system eliminates all of that.
Each valve uses a float mechanism to automatically stop flow the instant distilled water reaches the correct electrolyte level for that cell. Overfilling is physically prevented -- not just warned against. When you pull the fill gun, a check valve seals the port so there is no drip, no spill, and no acid splash.
Float valves stop flow at the correct electrolyte level in every cell -- no guessing, no overflow.
Connect your fill pump or hand bottle to one port and water all six batteries simultaneously.
Flexible tubing manifolds route between cells and batteries without rigid hard lines that crack over time.
Engineered specifically for Trojan Plus series 6V deep-cycle batteries -- valves seat and seal correctly without adapters.
The BG-U36V-7A ships as a complete, ready-to-install watering system for a six-battery 6V bank. Everything needed to replace existing vent caps and interconnect the cells is in the box:
A Flow-Rite hand pump or remote fill pump (sold separately) is recommended for the most convenient single-handed filling operation.
Flooded lead-acid batteries -- including the Trojan Plus 6V series -- lose water through normal charging cycles. Plates that are exposed to air sulfate rapidly, causing permanent capacity loss. Consistent watering after each charge cycle (not before) keeps plates covered, slows sulfation, and can add years to an expensive battery bank.
The Pro-Fill system is a direct replacement for the factory vent caps. No drilling, no battery modification, and no special tools are required for most installations:
Always water flooded lead-acid batteries after a full charge cycle, not before. Charging causes electrolyte expansion -- watering before charging can cause overflow and acid spills. After charging, connect your fill source to the Pro-Fill port, squeeze or pump until flow stops at all valves, and disconnect. The process typically takes less than 60 seconds for a 6-battery bank.
Tap water contains minerals that contaminate battery electrolyte and accelerate plate degradation. Use only distilled or deionized water with this system. Never add electrolyte (battery acid) through the Pro-Fill valves -- the float mechanism is calibrated for water only.
Flow-Rite offers manual squeeze bottles, hand pumps, and electric remote-fill pump systems that connect directly to the BG-U36V-7A quick-connect port. If your battery bank is in a difficult-to-reach compartment, the remote fill pump system routes a fill hose to a more accessible location -- no need to open the battery bay at all.