Tech Talk Archives 7

[Neweller]

Q
769 9/5/2002 2:12:04 PM 9/5/2002 TechTalk Staff TechTalk@newellcoach.com battery converter/charger The Newell house/engine start 12-volt electrical systems have remained remarkably unchanged for over 20 years. With few exceptions, all coaches have been equipped with flooded cell 8D batteries for both the engine start and the house banks of batteries. It is recommended not to mix two different battery types on a single charging source. Wanting to avoid the need for separate charging systems for each battery bank, we selected a single battery type to use on both banks that is technically a starting battery, but performs remarkably well in what would be considered a deep cycle application. We have seen typical battery life of 3 to 5 years. Flooded cell 8D batteries are readily available across the country and are relatively inexpensive, often in the range of $120 to $150 each. Both the engine and house batteries are charged from the engine alternator while driving, and from the 120 volt charger (a converter/charger years ago or an inverter/charger in more recent years) when ac current is available, be it generator or shorepower. The Litton Triad converter/charger incorporated in the mid-1970s was the first good, reliable charger we found that allowed for continuous electrical hookup without boiling batteries. The combination inverter/chargers introduced in the mid-1980s were even better, originally with Heart Interface products and now the Statpower ProSine 3000 watt sine wave inverter/charger being original factory equipment today. (As has been mentioned on this thread, Heart, Trace, and Statpower have all merged into one company in recent years.) While we have had good reliability and performance with flooded cell 8D batteries, through the years we have consistently had problems when we tried sealed gel cell batteries. While they are Òmaintenance free,Ó gel batteries typically have a life of two years or less in our application, with some failing within a few weeks. Here, the definition of Òmaintenance freeÓ comes into play. We have also equipped a number of coaches in recent years on special order with absorbed glass mat (AGM) batteries, a modern technology that is maintenance free, appear to be reliable, and provides marginally more electrical storage capacity than flooded cell batteries. However, the AGM batteries are quite expensive at about $400 each and can be hard to find out in the hinderlands when replacements are needed. We recommend AGM batteries for customers expecting to do a considerable amount of dry camping, but believe that the old fashioned, inexpensive, and readily available wet cell 8D battery is a good solution for the majority of customers.