Dennis Haynes typed: > Of the battery choices out there, a conventional flooded cell will be the > most tolerant of use and abuse and provide the longest life. Most of the > 12 volt deep cycle batteries or beefed up starting batteries and still > have short lives of one or 2 seasons. The golf cart batteries are a lot > more tolerant of heavy use. > > Of the common, reasonable price brands, Trojans are probably the best. > Best plates and a lot of active material in the plates. Yes there are > better such as Rolls Surrette but bring money. This is in agreement with what the designer at Blue Sky Energy (http://www.blueskyenergyinc.com/) told me last week. Trojans, he said, are "real" deep cycle batteries. > AGM and Gel batteries is still emerging technologies and the advertising > is a lot of hype. I asked the engineer about one of the claims made of AGMs: namely that they claim a higher charge efficiency (96%) as opposed to flooded cell batteries (85% to 90%). Charge efficiency is a measure of how well the battery converts charge energy into charge, not heat, so a higher number means more rapid charging. He disagreed and said that one would be hard-pressed to measure a significant difference between AGM and flooded cell batteries. "Snake oil," is the phrase he used. > For wiring and charging, the circuit needs to sized for both charging the > battery and any load connected to it. This includes inverters. The GC-2 > will pull about 40 amps off the alternator during the bulk charge. Add you > other loads. Best results will also be a direct line from the alternator. > #6 gauge. That's a good way. I have another view on the charging aspect of this, though. If the wire is skinnier, then its resistance will limit the initial flow of current into the battery. But as the battery comes up to charge the current into it naturally drops so the resistance of the wire becomes less of a factory. For many people, being able to deliver 40 amps into the battery for its first 15 minutes of charge might not be worth stressing about when 20 amps will just add another 15 minutes to the total charge time Of course, if one has a hefty bank of giant batteries that are severely depleted and only a short time to charge them, then giant alternators and garden hose-size wire may make a significant difference in how quickly you can get them up to full charge. But in our application, where the 100Ah group 27 battery is usually about 20Ah low in the morning, we have plenty of time to charge it up during the day, whether from solar or driving (stock alternator, puts about 16 amps initially into a lowish battery through my 6-gauge wire that runs from the starter battery. For us this is plenty.
> Also, you want a truly reliable relay. Most important that it > disconects when expected. You want double break contacts like in those > solenoid type cans. Not a small lighting relay. Yup. Hate to wake up in the morning to find that my engine battery got depleted along with the house battery because the relay's contacts fused together. -- Mike "Rocket J Squirrel" Elliott 71 Type 2: the Wonderbus 84 Westfalia: Mellow Yellow ("The Electrical Banana") 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano KG6RCR |
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