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groingo
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# Posted: 1 Aug 2014 18:39 - Edited by: groingo
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My Samlex battery charger has confirmed that the first charge was no fluke charging from same point to point in half the time as a conventional charger in fact 2.16 times faster or 13 hour is now a 6 hour charge using the same amount of input power which keeps the genny running at well below the 25% sweet spot for best fuel mileage.
With all this good news there is a bit of bad news, it looks to only be surface charging and the time saved is lost deep charging which it is not doing well,
it looks like the charge sensors are mis calibrated, will talk to them monday but for now solar is back on the table.
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MtnDon
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# Posted: 2 Aug 2014 09:56
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How are you gauging the state of charge?
Hydrometer or voltage?
Hydrometer readings are the only 100% sure method. Apply electrolyte temperature corrections too.
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MtnDon
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# Posted: 2 Aug 2014 10:08
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Also how long is the absorb charge phase? Is the time re-programmable?
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groingo
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# Posted: 2 Aug 2014 12:24 - Edited by: groingo
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I use both for testing but the volt meter works best because the plates are so large the hydrometer can only draw from the top 1 inch of the plates, you can't draw from deep in the battery just no room so hydro readings are all over the map.
State of charge entails lots of records and experience for example a full charge will always loose 0.60 to 0.43 volt as the batteries settle in after a charge, so voltage may start out when charge is completed at 13.18 but fall to 12.58.
The absorb phase is typically half of the overall charge time depending on how low the batteries were to start.
I think ultimately this charger will do the job, I just need more information and trial and error to see what does and doesn't work.
Let me ask you this on another topic, do you think a pure sinewave inverter is more efficient that a modified sine wave inverter?
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MtnDon
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# Posted: 2 Aug 2014 20:02
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Quoting: groingo do you think a pure sinewave inverter is more efficient that a modified sine wave inverter?
Depends. IF you look at just the efficiency of a modified sine wave vs a pure sine wave inverter you will generally find the modified sine wave inverter to be slightly more efficient, but only by a few percentage points. If the loads are resistive in nature such as incandescent lamps, toasters and the like this efficiency is true. However, when the loads connected to the inverter are motors then the wave form shape must be considered in the overall efficiency. Motors run more efficiently with a pure sine wave form (cooler and less noise too) meaning a motor may actually use more power when provided with modified sine wave form power. That will affect the overall efficiency of inverter and device combined.
So, it depends.
My personal bias is towards pure sine wave form inverters. I know anything I plug into it will operate and will operate with the device at peak efficiency.
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Re: hydrometer readings. I agree that voltages are most convenient to use. But unless / until you "know" the system voltage readings are prone to providing information that can be misleading. I use voltages as an everyday handy tool. But when I want to see how the cells are getting along I use a hydrometer. I actually use two. First I draw a large volume of acid from the cell using an old hydrometer housing that has an oversized bulb. I fill it and then shoot the electrolyte back into the cell. Repeat twice. I do all the cells like that to mix the fluid.
Then I use my hydrometer that has a smaller diameter fill tube and draw off just enough electrolyte to get a reading. If I'm careful I don't get air bubbles. Works for me.
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Quoting: groingo I just need more information and trial and error to see what does and doesn't work.
Not sure what you mean by that... What can you do other than start the generator, plug in the charger and let it go through bulk and absorb and then end up in float. Other than select the absorb time or choosing the number of days between charges. ??? I am a strong believer in the hazards / potential problems of permitting batteries sit in partial charge/discharge state and only recharging weekly. But that's me.
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groingo
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# Posted: 3 Aug 2014 00:03
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The sinewave question you verified and that is peak efficiency, I am looking for every edge I can get.
My trial and error is to gather information in different controlled conditions to build a battery behavior database again looking for patterns and the all elusive sweet spot.
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