We have a Heart Freedom 25 made prior to the Xantrex merger/takeover so I don't know how it compares to the units made under the Xantrex corporate umbrella. I'm pretty sure the equalization cycle has to be started and controlled from the remote panel--- I don't think it can be done at the inverter itself but I could be wrong. It is a timed process and if it runs its full time it takes about eight hours. Battery water MUST be topped off before the equalization process is started, and the battery(s) MUST be at a full charge already.
I have never found it necessary to add water during the equalization process or after it. But this could vary from boat to boat and battery type to battery type as well as the actual condition of the battery(s).
What is REALLY important is that you periodically check the temperature of the battery or batteries (by feel) during the equalization cycle. As the process continues the batteries can get quite warm to really hot. The marine electrical shop that installed our Freedom 25 said that if the batteries start getting really warm, stop the equalization cycle--- it's accomplished what it's supposed to accomplish even if it doesn't run the full cycle time.
FWIW the cycle initiation process on our Freedom 25 is to first disconnect any echo charger wires (the Freedom 25 can accommodate up to two echo chargers) and then with the charger on and the inverter off select "Setup" on the remote panel, then push "Setup" and "Charge" together and hold them down until the three battery condition lights (red, yellow, green) start to sequence rapidly or "flash" as the manual says. Stopping the equalization cycle early is just a matter of pushing the "Charge" button or shutting off the AC power to the inverter/charger and then turning it on again.
It's a good idea to check the water in the battery(s) after equalization to make sure the levels are still good. Also, don't forget to reconnect the echo charger wires if you have echo chargers.
Because equalization shoves a higher than normal voltage into the battery(s)--- up to 16 volts according to the Freedom 25 manual--- it's a good idea not to turn on any DC items on the boat during the cycle--- lights, instruments, electronics, pumps, etc.
It's also REALLY important to ventilate the area where the batteries are. Battery box covers should be removed or opened and the space ventilated so that the potentially explosive battery fumes will be rapidly dissipated. We open a floor hatch and put a small AC fan in the rear of the engine room blowing air to the front where the batteries are and out the engine room air intakes which on our boat are quite large. It's a good idea to check for battery fumes periodically during the equalization cycle to make sure they aren't building up.
