The charging at the 14.8 or 14.4 whatever your typical three stage converter does, is not the least bit harmful and is only for a short time anyway. You do have to disconnect the batteries when Equalizing at the high 15s into the 16s but that is a special routine not often done and converters can't do that anyway.
When a three stage converter says it will "Equalize" as a "fourth stage" all that means is it will do a shot of its 14something voltage every so often during the time it is doing its Float voltage.
That is not "real equalizing" as usually meant, which is done at 15.8 or 16v whatever for a few hours as a special session with a special charger that can do that.
