Stop opening every cell cap to check and fill your deep-cycle batteries. The Pro-Fill system replaces your existing vent caps with automatic shut-off valves interconnected by flex tubing, so you fill every cell to the correct level in a single water connection -- no overfilling, no acid spillage, no guesswork.
The Flow-Rite BG-U48V-BA-EA Pro-Fill kit is engineered specifically for 48-volt battery systems: the most common configuration in golf carts, large RV house banks, and electric vehicle platforms. It accommodates (8) 6-volt batteries or (4) 12-volt batteries wired in series or series-parallel to produce 48V.
Each automatic shut-off valve mounts directly into an existing cell opening. When you connect a water source and fill, each valve closes the moment electrolyte reaches the correct level -- so every cell gets exactly the right amount of water, every time. The 129 flex manifold segments snap together to route around battery terminals and hold-down hardware without tools.
The included Eagle Eye visual level indicator gives you a quick at-a-glance confirmation that the bank is fully watered before you disconnect. The indicator window changes appearance when cells are full, eliminating any doubt.
Float-controlled valves stop water flow at the correct electrolyte level in every cell -- no overfill, no dry cells.
Visual sight gauge confirms all cells are full before you disconnect the fill hose.
Rigid-yet-flexible tubing segments route around terminals, straps, and box edges without cutting or special tools.
Designed for (8) 6V or (4) 12V deep-cycle batteries -- covers most 48V golf cart and RV bank layouts.
Lead-acid deep-cycle batteries consume water during charging as hydrogen and oxygen gas off the electrolyte. Cells that run low on water expose the lead plates, causing irreversible sulfation and dramatically shortened battery life. Consistent, correct-level watering is the single most impactful maintenance task for flooded lead-acid battery longevity.
Note: A separate water supply hose or hand pump (sold separately) is required to deliver water to the system. This kit does not include a pump or storage bottle.
The Pro-Fill system is designed exclusively for flooded (wet-cell) lead-acid batteries with removable vent caps. It is not compatible with AGM, gel, lithium (LiFePO4), or sealed VRLA batteries. Verify that your battery bank is a vented flooded design before ordering.