The direct fill link is the most popular filling device because it is so easy to use.
Depending on water quality, the direct fill link can be connected to a standard garden hose, a deionizer, an 8 gallon Aqua Sub Jr. cart or 25 gallon Aqua Sub cart to put water directly into the batteries. The direct fill link has a built-in flow indicator and pressure regulator, reducing pressure down to 10 PSI. It can handle up to 90 PSI from the water source. Water sources with greater pressure should use a brass pressure regulator to reduce incoming pressure.
The direct fill link is not recommended for use with Philadelphia Scientific® injector systems or Watermaster® systems.