What Are The Implications of Ferroresonant Battery Chargers?

Question:

Thank you for your presentation last night. I started thinking that I may have a ferroresonant charger (which could account for some of the problems I have been having). The charger is a Newman RM 15 which was installed in 1990. I’m at “a bit of loss” because the manufacture’s manual says that the charger provides a float charge and will not overcharge. However, the schematic shows SCRs and it does not look like a smart charger. I thought that I would ask your opinion before I go to the expense of purchasing a new charger.

Answer:

Based on my research, the Newmar RM 15 is a ferroresonant charger. The charger will tend to overcharge the batteries ever so slightly and they will eventually boil over. As per the presentation, I would recommend changing to a smart charger. For instance, we have had lots of success with the Promariner ProNautic charger.  - Jeff