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#11
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#12
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![]() "chuck" wrote in message ... Hello Doug, The data I see suggests that if you have a 6 ampere load and you measure 12.0 volts, the battery is at something like a 15% state of charge. (Assuming a 420 AH bank) My experience does not substantiate that. Even a flooded battery at 12V is more than 15% charged. As I posted elsewhere, a 6 ampere load on a new, fully charged battery bank of 420 AH should give an almost no-load voltage reading. That's true. 6A is a gnat taking a leak to a 420 AH bank. I'm talking a real load like my fridge drawing 50A. Unfortunately, we don't know the state of charge (either perceived or actual) of the original poster's bank when he measured 12.0 volts under a 6 ampere load. True. No point in taking this further without more info. Doug Regards, Chuck Doug Dotson wrote: Not at all, but 12.0 is about as low as you want to go. If you measure a fully charged battery you will notice it is around 12.6 rather than the typical 12.8 for a liquid battery. Doug wrote in message oups.com... So I shouldn't panic when the voltage goes down to 12.0 with an average of about a 5 amp load? I will separate the batteries tomorow when they are down to the 12.1 and are down about 80 and charge only one and see if the other comes up. Thanks. Its been a great trip, everyone should go cruising |
#14
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Thanks for the info, I have a Zantrex smart charger and have monitored
it closely as we have been living on the boat since last Aug, I set it for AGM batteries and when I got it and have the 60 amp charger with the internal voltage regulator removed. It charges at 50 amps for about 40 min then starts dropping down as the voltage rises. I have most consistently charging from a -80 to about -20 daily. This has met our demands and keeps the motor running down to about an hour. To go to full charge or till the green light flashes on the Link 10 batteries monitor would take another hour. Fully charged is about 12.7V. When we are moving I usually run the motor for several hours and correct for any miscalculation in the monitor. I thought this was reasonable from the literature I had red and from the sales person of the batteries. I then found the batteries operation manual on line and saw that they recommended that the batteries be fully charged each time they are charged. This is unreasonable for a cruiser and I wish I new that before I purchased them. They only reason I went with the sealed batteries is that I don't have an adequate vented batteries box. The gel cells were working fine in the boat, but they were 12 years old and swelling on the sides. We are cruising for a year and I didn't want problems, which I am having. I now see everyone and his brother with wet cells mounted inside the older boats and vent them into the cabin. The literature did recommend that I equalize them at 15.5 Volts for 5 hours. I did that and noticed some improvement. I am thinking that they are sulfated and wonder if I can get more life back in them by doing it again. I am worried about doing more damage though. I will read the article, and again, thanks to everyone for you opinions. John |
#15
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I think the deal with charging them to 100% is bull. We have had ours for 5+
years and during a year of cruising only charged them to 80% on a regular basis. Only charged them to 100% on the rare occation we pulled into a marina. They are still performing fine. I've never equilized them since back when I got mine the concept of equalizing a sealed battery was unheard of. My charger doesn;t even support equilizing an AGM. After 5+ years they are performing about as well as they were when they are new. Doug wrote in message oups.com... Thanks for the info, I have a Zantrex smart charger and have monitored it closely as we have been living on the boat since last Aug, I set it for AGM batteries and when I got it and have the 60 amp charger with the internal voltage regulator removed. It charges at 50 amps for about 40 min then starts dropping down as the voltage rises. I have most consistently charging from a -80 to about -20 daily. This has met our demands and keeps the motor running down to about an hour. To go to full charge or till the green light flashes on the Link 10 batteries monitor would take another hour. Fully charged is about 12.7V. When we are moving I usually run the motor for several hours and correct for any miscalculation in the monitor. I thought this was reasonable from the literature I had red and from the sales person of the batteries. I then found the batteries operation manual on line and saw that they recommended that the batteries be fully charged each time they are charged. This is unreasonable for a cruiser and I wish I new that before I purchased them. They only reason I went with the sealed batteries is that I don't have an adequate vented batteries box. The gel cells were working fine in the boat, but they were 12 years old and swelling on the sides. We are cruising for a year and I didn't want problems, which I am having. I now see everyone and his brother with wet cells mounted inside the older boats and vent them into the cabin. The literature did recommend that I equalize them at 15.5 Volts for 5 hours. I did that and noticed some improvement. I am thinking that they are sulfated and wonder if I can get more life back in them by doing it again. I am worried about doing more damage though. I will read the article, and again, thanks to everyone for you opinions. John |
#16
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"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
: Under load the AGMs sag more than flooded batteries but then level out and exhibit proper capacity. Makes sense. The AGMs can't replace the acid-now-turned-to-lead-sulphate with fresh acid like the wetcell with its convective electrolyte currents, constantly refreshing the acid touching the surface of the plates. |
#17
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![]() I rechecked my voltage settings and they are right where the manufactuer recommends. I have both the Xantrex truecharger for shore power as well as the smart charger for the alternator. So I do not think I have burned them up, but keeping then between -80 and sometimes -100, then charging up to -20 on a 420 amp hour system seemed resonable. From the ressearch I have done and other crusiers, it seems like the older ones held up better then the new ones. I hve seen several articles complaining about their performance, in ON and this month in Latitude 38. I do remember that once we started living on the hook last Oct the voltage would be at 12.2 with -80. But was told not to worry about it because it could be measuring lower voltage from having a load. So I didn't and this morning it is at 12.2 with onle -45 amp hours, after being fully charged to a standing voltage of 12.7 yesterday. It doesn't seem to go to the 12.85 like the starting battery of the same vintage and type does. I didn't like the ON article that was posted, it doesn't address what crusiers should do to make them perform. If I would have seen the article before I purchased them I would have never done so. The article stated that the flodded type have the same problems as AGMs with sulfation on the plates. But dosent follow up that equilizing is a common method of maintaining the floded type, but the manufacturer only recently recommends it on the Lifeline AGMs. If you follow the article, the batteries should be sold with a big warning lable and a good set of instructions. I was told that they were bullet proof, could take abuse and all the amp hours you can through at them. The article makes it sound like if you are .1 volt off and don't fully recharge, you are tosting the batteries. That was not what was sold to me. If any one has experence in bringing them back to life I would love it. I want to leave from Cabo to Hawaii in three weeks and am contimplating diching them and putting in flodded before I go, but what a waste. I will contact Lifeline and see if tehy have any support in Mexico, unlikly. Thanks for all the suggestions. John S/V Pangea |
#18
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#19
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Check out this video at the Rolls battery site for interesting info on how
they actually make batteries: http://www.rollsbattery.com/ video link is on left side. -- Keith __ "Twenty years from now you will be more disappointed by the things you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." - Mark Twain "Larry W4CSC" wrote in message ... wrote in ups.com: The article stated that the flodded type have the same problems as AGMs with sulfation on the plates. But dosent follow up that equilizing is a common method of maintaining the floded type, but the manufacturer only recently recommends it on the Lifeline AGMs. If you follow the article, the batteries should be sold with a big warning lable and a good set of instructions. I was told that they were bullet proof, could take abuse and all the amp hours you can through at them. The article makes it sound like if you are .1 volt off and don't fully recharge, you are tosting the batteries. That was not what was sold to me. Price is not an indication of quality in all things. Look inside one. Very thin (they have to wrap them around a post you know)lead plates separated by a gauze like mat soaked in sulphuric acid that, once used up in an area, cannot MOVE like a LIQUID electrolyte can to cool the plates with convection and mix with the rest of the electrolyte in the cell. All this reminds one of gelcells with the jelly acid that doesn't move either and when it "shrinks" away from the plate, that place is dead as there is no contact. Bulletproof it's not. I'm concerned about the heat insulating qualities of this glass mat. We use fiberglass to insulate our homes. How hot does this rolled up battery get INSIDE when it is charged or discharged? How can you cool something efficiently rolled up so tightly? At what temperature does the glass mat and little rolled up plates warp? boil into steam? God the red starting AGM in my stepvan just melted when one cell shorted out! Let's ask some embarrassing questions about "sulphation". Lead is turned into lead sulphate to make free electrons. As long as the lead sulphate doesn't get too concentrated, it stays in solution in the electrolyte so we can force it to revert back to sulphuric acid and elemental lead at the surface of the plates. That's how it works, right? If we kill it too dead, lead sulphate crystals form on the plates, insulating the lead plates from the electrolyte. The cell is "dead" because the sulphuric acid is used up, converted into lead sulphate crystals and we can't recover it because the electrolyte now becomes almost an insulator, distilled water. In a wetcell, lead sulphate crystals can and do fall off the lead plates, exposing more lead as the crystals fall to the space at the bottom of the container under the plates made just for this purpose. Life goes on, the cell now has less "capacity" to charge because there is less acid in the cell to use up as it discharges. How do lead sulphate crystals precipitate out of a rolled up, acid soaked guaze battery where nothing can move? Nothing can move anywhere in the AGM (or gelcell) battery all squeezed inside that cylinder case, can it? I can't adjust the specific gravity to make up for some of the acid loss because it's all sealed. Balancing the cells adjusting acid concentrations is impossible. What you get, you get. No thanks. I think AGM batteries were invented to simplify battery manufacture and the marketing mongers saw a great opportunity to create market hype of a "new" and "extraordinary" new product we can sell at exhorbitant profits. I'll keep my temperature-compensated hydrometer and little distilled water filler monitoring what is really going on in the cells. Running my ham station is a set of "Edison Cells" given to me by a friend who used to be a Holiday Inn innkeeper back in the 1960's. These cells use Nickel and Iron for plates, making them an environmental disaster of nickel pollution if you dump them, which you never need to do. The electrolyte is potassium hydroxide, a base, not an acid. The date on the cells reads 1947, except on one cell that reads 1949. Nickel-Iron batteries last virtually forever, of course making them a target to get rid of them by battery manufacturers. These cells ran an old Holiday Inn telephone exchange that required a live operator running a plugboard manually. The cells are near 2V each. I have 7 in series charging them with a modified simple SCR charger since the 1970s. Fork lift trucks used to all be nickel-iron batteries you just charged and put distilled water into as it is used up. Too bad we can't put Ni-Fe batteries in a boat and replace them every 80 years or so....(c; Those are great batteries! I found a website "expert" who says they are awful. I disagree: "NiFe (Nickel Iron) Energy storage density = 55 watts per kilogram Alkaline-type electric cells using potassium hydroxide as the electrolyte and anodes of steel wool substrate with active iron material and cathodes of nickel plated steel wool substrate with active nickel material. This is the original "Edison Cell". Very long life. ..."Our experience with customers using alkaline batteries in stand alone AE systems suggests that they may have as many drawbacks as advantages when compared to lead-acid type batteries. We suggest that potential alkaline users evaluate the economics and performance claims carefully to determine the suitability of any battery being considered..." Christopher Freitas Trace Engineering Downsides: 1. Low efficiency - may be as low as 50%, typically 60-65%. 2. very high rate of self-discharge 3. high gassing/water consumption 4. high internal resistance means you can get large voltage drops across series cells. 5. high specific weight/volume This also means that the output voltage varies with load and charge much more than other batteries. If you are using an inverter, the inverter needs to be designed with these voltage swings in mind. You may not be able to use NiFe's if your system depends on a stable voltage, for example if you are running certain common DC appliances such as a refrigerator directly off the batteries. Also when using NiFe's to power DC lighting, you will notice the light intensity fluctuates. One could always use a voltage regulator to feed those appliances that need it, but that would decrease the efficiency even more. Currently, it appears that the only source for new NiFe batteries is from Hungary, and we have heard mixed reports on them. In short, we do not recommend them unless they are nearly free. The high losses in charging and discharging will add an extra 25-40% to the size of the solar panels you will need for the same energy usage. In short, despite some hype about long life and thousands of cycles, we feel that overall these batteries are a poor choice for nearly all solar applications." It's a moot point as you can no longer buy them......Did I mention you can discharge them DEAD and they charge right back up to FULL capacity for DECADES?......Of course, this guy saying this SELLS LEAD-ACID BATTERIES!! |
#20
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Keith,
Very informative, thanks. Paul Keith wrote: Check out this video at the Rolls battery site for interesting info on how they actually make batteries: http://www.rollsbattery.com/ video link is on left side. |
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