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#21
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"Larry" wrote in message ... "Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in news:t- : AGMs can be charged very fast. But not like the LiIon technology. Let's charge a 500AH AGM battery in 30 minutes from 50% at 500A and watch it happen. The specs say it will work. I don;t have the means to test it. I'll be some 500 yards off observing the proceeding through HEAVY lenses..(c; Your heavy lenses indicate your nearsightedness with regard to anything involving AGMs. You have indicated your distain for the technology in the past. I expect nothing more. Question - If AGMs are such great chargers, so fast, why don't Honda and Toyota hybrids have AGM batteries...instead of Ni-MH?? Well, AGMs are batteries not chargers. The batteries in the hybrids are not deep cycle batteries. They are 6AH at 201+ volts. They are only good for 6 or 7 miles if used as the sole drive source and will be severely dammaged. -- Larry |
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#22
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Your old regulator was junk. No wonder doing it manually worked better as
long as you pay attention. How long did you charge them manually and how long did they last? "Andy" wrote in message ups.com... The Floating Bear wrote: I found in a wonderful resource I had not seen before, http://www.practical-sailor.com/news...Questions4.pdf a reference today to a design in The 12 Volt Doctor's Practical Handbook for an alternator controller. It's not an easy book to get in the UK and I wonder if anyone who has a copy would be able to tell me more about the section of the book that deal with this project, or perhaps scan and mail it if it's not too long. Regards, Jerry (Remove the obvious from my address to mail me) You don't need plans to build a manual alternator controller. Just buy a rheostat rated for 12 volts and however much current will be going into the alternator field wire and hook it up between the battery and the alternator field wire. Thats what I did when my regulator died when I was cruising, and it worked like a charm; charged the batteries much quicker than the old regulator. You have to have a good voltage meter on your battery bank and know at what voltage to start tapering down the charge so you don't fry your batteries. Andy |
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#23
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Doug Dotson wrote:
"Andy" wrote in message You don't need plans to build a manual alternator controller. Just buy a rheostat rated for 12 volts and however much current will be going into the alternator field wire and hook it up between the battery and the alternator field wire. Thats what I did when my regulator died when I was cruising, and it worked like a charm; charged the batteries much quicker than the old regulator. You have to have a good voltage meter on your battery bank and know at what voltage to start tapering down the charge so you don't fry your batteries. Andy Your old regulator was junk. No wonder doing it manually worked better as long as you pay attention. How long did you charge them manually and how long did they last? After my regulator died I used combinations of lightbulbs as my regulator for a couple of months. (See Nigel Calder, Boatowners Mechanical and Electrical Manual, 2nd ed. page 71) Then I finally found a rheostat, and used that from Panama to San Diego, another 4 months, so I used some form of manual control for 6 months cruising full time. The batteries still seemed just the same when we sold the boat 6 months after we got back. Regulators are not magic; all they do is adjust the current flowing into the alternator field wire to maintain a certain voltage in the battery bank when charging. Once you do a little reading and learn what voltage(s) your batteries should be at when charging you can do just as good a job as any regulator. The only advantage of a regulator is that it can't get distracted and forget to turn down the current to the alternator field wire. Once you have used a manual contoller for a while you get a feel for when you need to turn down the current in the charging cycle and it becomes habit. Andy |
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#24
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"Andy" wrote in message oups.com... Doug Dotson wrote: "Andy" wrote in message You don't need plans to build a manual alternator controller. Just buy a rheostat rated for 12 volts and however much current will be going into the alternator field wire and hook it up between the battery and the alternator field wire. Thats what I did when my regulator died when I was cruising, and it worked like a charm; charged the batteries much quicker than the old regulator. You have to have a good voltage meter on your battery bank and know at what voltage to start tapering down the charge so you don't fry your batteries. Andy Your old regulator was junk. No wonder doing it manually worked better as long as you pay attention. How long did you charge them manually and how long did they last? After my regulator died I used combinations of lightbulbs as my regulator for a couple of months. (See Nigel Calder, Boatowners Mechanical and Electrical Manual, 2nd ed. page 71) Then I finally found a rheostat, and used that from Panama to San Diego, another 4 months, so I used some form of manual control for 6 months cruising full time. The batteries still seemed just the same when we sold the boat 6 months after we got back. Regulators are not magic; all they do is adjust the current flowing into the alternator field wire to maintain a certain voltage in the battery bank when charging. Once you do a little reading and learn what voltage(s) your batteries should be at when charging you can do just as good a job as any regulator. The only advantage of a regulator is that it can't get distracted and forget to turn down the current to the alternator field wire. Once you have used a manual contoller for a while you get a feel for when you need to turn down the current in the charging cycle and it becomes habit. But you can never do it as accurately as a good charge controller. I doubt that manually one can adjust the voltage according to the battery temperature when the voltage difference is 0.05 volts per degree C. A couple tenths of a volt can be the difference between undercharging and boiling off the electrolyte. In a pinch doing it manually will get you home. 6 months doesn;t tell the story. Andy |
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#25
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"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
: Well, AGMs are batteries not chargers. The batteries in the hybrids are not deep cycle batteries. They are 6AH at 201+ volts. They are only good for 6 or 7 miles if used as the sole drive source and will be severely dammaged. Hmm....Ni-MH batteries may be run completely dead, over and over....unlike old lead-acids that eat holes in the plates, even if you wrap the plates around fiberglass gauze. I deep cycle nearly all my Ni-MH batteries all the time without destroying them. Some of them are 10 years old. My disdain, on the other hand, is more about the AGM battery HYPE than the AGM batteries themselves. They are JUST lead-acid batteries, not some magic wonder the marketing depts try to make them out to be to justify the awful price. Look closely at them. They are CHEAPER to make than a proper wetcell. Thin lead so you can wrap them tightly, the only way they'll get contact with the electrolyte soaked into the gauze....no need for exotic plate structures to hold the soft lead in place in a liquid medium. No fancy separators to keep the plates from shorting out in a liquid medium. Where's the wonder technology? I don't see any Palladium or Platinum pieces to justify them selling for triple, do you? No, it's the HYPE that grinds my skin. There's AGM batteries in my stepvan, 2 of them to get enough current to crank the V-8 diesel. One failed, already, getting so hot the case melted. The gauze must have had a hole in it inside somewhere. AGM "technology" came from the same capacitors (rolled up plates with insulators instead of soaked gauze between the plates in a round tube) we've been making since the 19-teens. It's not "new".... -- Larry |
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#26
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"Larry" wrote in message ... "Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in : Well, AGMs are batteries not chargers. The batteries in the hybrids are not deep cycle batteries. They are 6AH at 201+ volts. They are only good for 6 or 7 miles if used as the sole drive source and will be severely dammaged. Hmm....Ni-MH batteries may be run completely dead, over and over....unlike old lead-acids that eat holes in the plates, even if you wrap the plates around fiberglass gauze. I deep cycle nearly all my Ni-MH batteries all the time without destroying them. Some of them are 10 years old. AGMs can be run down flat and left that way for long periods of time with no ill effects. My disdain, on the other hand, is more about the AGM battery HYPE than the AGM batteries themselves. They are JUST lead-acid batteries, not some magic wonder the marketing depts try to make them out to be to justify the awful price. Look closely at them. They are CHEAPER to make than a proper wetcell. Thin lead so you can wrap them tightly, the only way they'll get contact with the electrolyte soaked into the gauze....no need for exotic plate structures to hold the soft lead in place in a liquid medium. No fancy separators to keep the plates from shorting out in a liquid medium. Where's the wonder technology? I don't see any Palladium or Platinum pieces to justify them selling for triple, do you? Beats me. But since they far outlast liquid batteries they end up being cheaper in the long run. No, it's the HYPE that grinds my skin. There's AGM batteries in my stepvan, 2 of them to get enough current to crank the V-8 diesel. One failed, already, getting so hot the case melted. The gauze must have had a hole in it inside somewhere. AGM "technology" came from the same capacitors (rolled up plates with insulators instead of soaked gauze between the plates in a round tube) we've been making since the 19-teens. It's not "new".... No one said they are new. They have been used in military aircraft for at least 20 years. -- Larry |
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#27
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"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
: AGMs can be run down flat and left that way for long periods of time with no ill effects. Amazing.....Well, this ****ing contest is over. We'll agree to disagree. -- Larry |
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#28
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"Larry" wrote in message ... "Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in : AGMs can be run down flat and left that way for long periods of time with no ill effects. Amazing.....Well, this ****ing contest is over. We'll agree to disagree. -- Larry Good idea. You've made a career over the past few years of poo-pooing AGM batteries even though they have a proven good track record. |
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#29
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If you can hear a rev drop in your engine from the alternator, you are
already charging at close to its maximum output. I think the real issue is that you are only charging 10 minutes at a time, not nearly enough to bring the batteries back to full charge or close to it. I'd recommend getting a solar panel which will keep the batteries topped off at your mooring. |
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