Yes, it is confusing. I wish Iota would change their marketing
literature to make things clearer.
The IQ-4 is pre-programmed for the following voltages:
"Equalization" stage........not described anywhere.
I believe Iota's "equalization stage" to be just a repeat absorption or bulk stage voltage....14.2-14.8VDC for a short time. This is not a true equalization stage. Flooded batteries need at least 15.5-16.5VDC for true equalization, extended over several hours.
The IQ-4 preset voltages are not individually adjustable. However, it is possible by adjusting a single
trim pot to "pull" the voltages up or down....all of them at once.
I have "pulled" mine up a bit for 13.8VDC float level (which also pulls the other two stage voltages up a bit). For me, with my T-105 golf-cart batteries -- carefully monitored -- this works better and gives me longer battery
The pot is accessible behind a piece of tape at one end of the charger...you don't need to open the case.
With your batteries fully charged, you should be seeing a float voltage of about 13.6VDC. If you're seeing less than this, I would suspect your voltmeter first. Be sure you're measuring voltage at the output of the charger.
Then, compare that to the voltage at the battery
terminals. If there's a big difference, you either have resistance in the wiring
(terminals, wire size, etc.) OR, possibly, batteries which have been compromised in some way.
It's also a very good idea to check your voltmeter against a known good one.