It seems you are trying to determine the state of charge of your lithium batteries. The best solution and most accurate is to use a battery monitor like the Victron BMV-712 or the or the Victron Energy Smart Shunt. Using other methods is just futile. Don't get hung up on the voltage the charger hits, they only last for a short time then drop back to 13.5-13.6 resting voltage of the battery. If Battleborn suggested the Progressive Dynamic 4655 (LI) charge converter and that's what you installed your good to go, you didn't say LI. That converter is set for 13.6V to 14.6V the other version the way I understand is set-up for lead acid and its the 4655. I use the WFCO 9855LIS. If you are unsure what version you have give PD a call they have good tech support.
The step issue is interesting, I have had my PC for 3.5 years and haven't had an issue. I have however taken it down once and regreased everything. I know one big issue, people stepping on it while its in motion, this will strip the gears. If you have young kids around it seems they want to stand on it while its moving, bad idea, it decreases the life expectancy.