Bulk-Absorption Charging Voltage
2 Concord 8D (258 AH each) Freedom 25 Inverter-Charger (130 amp) Trimetric 2025 Gauge I'm dry camping and charging my batteries. They were 30% discharged. My Concords call for 14.2-14.4v absorpti...
Forum Discussion
Referring to the two o'scope photos above .... I wouldn't say the PD was bringing the Onan to it's knees. The EU2000i isn't doing so good either. For both generators, the current sine wave tops and bottoms are getting flattened, and both voltage sine waves are terrible. The PD is definitely presenting a screwy load to both generators.
For informational purposes, there's an excellent concise summary by Wayne Dohnal in this forum thread:
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/25119121/srt/pa/pging/1/page/2.cfm
Here's a quote of Wayne's comment from that thread:
"It has been a long time since I learned this stuff and my explanations probably aren't the best, but here's a shot at it. The only pure form of alternating current is the sine wave. Any other waveform is composed of multiple sine waves added, or combined together. One of the worst waveforms, a pure square wave, is made up of an infinite number of sine waves added together. In the distorted generator picture, the principal component is a 60 Hz. sine wave. The distortions mean that there are additional sine waves at other frequencies, and lower amplitudes, added in. These other-frequency sine waves are in most cases undesirable, resulting in higher transmission losses (wires and equipment run hotter), emission of radio frequency interference, and in some cases the connected equipment not working right. As others have said, almost all electrical devices have no problem whatsoever with the distorted waveforms from small conventional generators. Problems are really rare. The one I've heard most often is the timer on some microwave ovens not keeping correct time because of the waveform distortions. As a comparison, some problems are seen with "modified sine wave" inverters, whose output is closer to a square wave. This waveform is much, much dirtier than what comes out of the generators, yet many RVers have 100% success with it."
For informational purposes, there's an excellent concise summary by Wayne Dohnal in this forum thread:
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/25119121/srt/pa/pging/1/page/2.cfm
Here's a quote of Wayne's comment from that thread:
"It has been a long time since I learned this stuff and my explanations probably aren't the best, but here's a shot at it. The only pure form of alternating current is the sine wave. Any other waveform is composed of multiple sine waves added, or combined together. One of the worst waveforms, a pure square wave, is made up of an infinite number of sine waves added together. In the distorted generator picture, the principal component is a 60 Hz. sine wave. The distortions mean that there are additional sine waves at other frequencies, and lower amplitudes, added in. These other-frequency sine waves are in most cases undesirable, resulting in higher transmission losses (wires and equipment run hotter), emission of radio frequency interference, and in some cases the connected equipment not working right. As others have said, almost all electrical devices have no problem whatsoever with the distorted waveforms from small conventional generators. Problems are really rare. The one I've heard most often is the timer on some microwave ovens not keeping correct time because of the waveform distortions. As a comparison, some problems are seen with "modified sine wave" inverters, whose output is closer to a square wave. This waveform is much, much dirtier than what comes out of the generators, yet many RVers have 100% success with it."
