 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Driving, Maintenance, Tuning / Maintenance and Repair / May 2005To trickle or Not Trickle! please help a battery noobie with a 12v Gel battery question
Hi. After reading previous google posts, and my eyes bleeding due to the toxic nature of my 17 inch crt monitor.. i have decided to ask the forever question of: Whats the best way to charge a 12volts marine deep cycle battery? some people claim they can take a beating and to charge them at 10a for 6 hours others claim to charge them at 2amp for 20 hours, slow charge is the best way to go they claim I currently own a charger with only two settings. 2a ( trickle charge ) or 10am. I have been charging the battery at 10a please advise >Hi. > [quoted text clipped - 14 lines] > >please advise My advice is go buy a computer-controlled charger like I did and let the circuitry decide what to do. You'll get 3-stage charging when you select deep cycle. Fast-medium-slow,off/on maintenance 2 amperes. I have _many_. My latest is the Schumacker Model Sc1200A Speed Charger, which pumps high frequency pure DC. Connect it, plug it in, and forget about it. Lg > >Hi. > > [quoted text clipped - 24 lines] > > Lg Posters here know that Lawrence is very proud of his smart charger. I'm not sure about how one "pumps high frequency PURE DC" though. I suspect he means pulsed DC. A smart charger is nice if you can afford it. But the poster asks about the charger that he has, not the neat one Lawrence purchased. It doesn't matter if you use the 2A or the 10A charge assuming the battery is rated to take charging at those rates. Usually they print that info on the side of the battery. If it really is a small GEL battery then maybe 10A is too fast. You better check that out. If you don't have a smart charger, the key is to know when the battery is fully charged and not go beyond that point. You can do that pretty much with a cheap voltmeter. Personally, I do not like to go away and leave a charger unattended, whether it's a smart charger or not. And I own about every type made. Too many things can go wrong. >> >Hi. >> > [quoted text clipped - 30 lines] >I'm not sure about how one "pumps high frequency PURE DC" though. I >suspect he means pulsed DC. High frequency pulsed DC, not like 60 Hertz chopped, but more like this kind of sawtooth IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII above ground at 13.4 volts, or whatever it needs to be at in order to get the battery back in shape as quicly and safely as possible. It might start out at 12 amperes, drop down to 8, end up at 2 amperes, and I have a =DC= CL-Amp meter to verify what it is doing, so I know *how* it behaves when hooked up, but for those that want to watch the voltage, there is a nice red LED readout on the front that will tell you to the tenth of a volt, % of charge on battery, or Alternator %age depending on which button you push. >A smart charger is nice if you can afford it. With batteries going for $75 a crack, I can't afford -not- to have it. > But the poster asks about >the charger that he has, not the neat one Lawrence purchased. [quoted text clipped - 5 lines] >is fully charged and not go beyond that point. You can do that pretty >much with a cheap voltmeter. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >Personally, I do not like to go away and leave a charger unattended, >whether it's a smart charger or not. And I own about every type made. >Too many things can go wrong. Heck I hook em up in the garage all the time and let em run overnight, cause I make so many short trips I think I pull more current than I put back in with the alternator. Never had a problem yet. Detached garage of course, and -well- ventilated. Lg > high frequency pure DC. OW! I think that statement just damaged my brain. >> high frequency pure DC. > >OW! I think that statement just damaged my brain. Pure DC only means, that the current flowing in the circuit is ALWAYS moving in one direction, and one direction only. Convention says, from plus to minus, electronics says from minus to plus. That could hurt your brain a *little,* but nothing a Tylenol shouldn't cure. What this circuit does is VARY the magnitude of voltage at, a high frequency, with the RMS value, being the mean, determining the current through the circuit. This is apparently a faster way to charge a battery WITHOUT doing any damage to it. IOW, it is getting *spurts* of high voltage, and then dropped back to a lower voltage, rather than being run continuously at the mean between the peak and lowest values. This is a somewhat unfamiliar principle with those who haven't been following the leading edge of charging circuits as I have, so I am not surprised at your reaction. BTW, this also helps break up sulfiding that may be on the plates. There is a reason to do it this way. You might want to do some research. Lg >>>high frequency pure DC. >> [quoted text clipped - 3 lines] > moving in one direction, and one direction only. Convention says, > from plus to minus, electronics says from minus to plus. I have not problem with the term "Pure DC" although it doesn't mean what you typed above. It means "DC without ripple" or DC with no AC component. 'DC' by itself means what you typed above. "High frequency pure DC" is an oxymoron. If there is any frequency component at all, then the DC is not pure. >>>>high frequency pure DC. >>> [quoted text clipped - 10 lines] >"High frequency pure DC" is an oxymoron. If there is any frequency >component at all, then the DC is not pure. I disagree. There is such a thing as DC with an AC component. With the AC component missing, you're left with pure DC. Since there is no AC component, but just a square wave or sawtooth oscillating back and forth between a higher DC voltage and and lower DC voltage, it is pure high-frequency DC. I haven't bothered to put a scope on it to see which of the two it is, but I highly suspect it's a square wave. Periodicity, frequency, has nothing to do with the definition of *pure.* If the voltage sat at 15 vdc for 1 hour, and then dropped to 13.5 vdc for 1 hour, and then went back to 15 vdc for an hour, and dropped back to 13.5 vdc for one hour, YOU would be calling it "pure dc." The frequency component does nothing to change the fact that this is what it is. Your periodicity, or frequency, would be 1 cycle/hour. The fact that mine is more rapid just changes the number, not the nature. Now you deserve a headache. Lg >>>>>high frequency pure DC. >>>> [quoted text clipped - 30 lines] > > Lg What's the difference between, say, 15VDC as you describe and 7.5VDC with 7.5VAC added to it? nate  Signaturereplace "fly" with "com" to reply. http://home.comcast.net/~njnagel >>>>>>high frequency pure DC. >>>>> [quoted text clipped - 35 lines] > >nate DC is pushing current in 1 direction only, therefore it can be thought of as a vector. Magnitude and direction. AC is pushing current in 2 directions, therefore it can be thought of as two vectors in -serial- arrangement. The RMS root mean square of the AC, is the DC equivalent. IOW, if you have peak to peak 100 VAC, the rms is .707 times that, or 70 volts, which is the same as 70 volts DC. The Peak to Peak of AC is 1.2 times ( the reciprocal of .7 ) of the root mean square. Now putting a 1.5 volt battery in SERIES with another 1.5 will give you 3 volts. If you put them in opposition to eachother, aim the vectors at eachother with regards to polarity, you end up with ZERO volts. 1.5 pushing one way, and 1.5 pushing the other way, cancel eachother OUT. No different with an AC *component* on a DC network, except you have RMS AC working against the DC in exactly the _same_ manner. Is that clear? Probably not. You're "only" an engineer. Lg >>>>>>>high frequency pure DC. >>>>>> [quoted text clipped - 59 lines] > > Lg Perfectly clear. The point is that DC with an AC component is not pure DC. Pure DC makes a straight line across a 'scope when you look at it. nate Signaturereplace "fly" with "com" to reply. http://home.comcast.net/~njnagel >>>>>>>>high frequency pure DC. >>>>>>> [quoted text clipped - 64 lines] > >nate Well Nate, it there is not supposed to be any AC component on this "smart charger's" output, although if I get time later today I will put a scope on it for the heck of it. And if you change your sweep rate to a high enough number, you -will- see a straight line across the scope, except it should look like a higher DC value, and then drop to a lower one above Zero somewhere, depending on what the computer chip and algorithm *think* the battery needs based on feedback on the hook-up wires. Except it will oscillate back and forth between the higher DC value and the lower DC value so quickly you will think you are looking at two lines at the same time, depending on the latency of the monitor. Then if you change the sweep rate you will see you've got a square wave. For some reason, the MFGR chooses to call this "high frequency DC." You have to call the MFGR to figure out why marketing has come up with this buzzword ;) I haven't a clue, but if you know anybody in marketing, you know they're not the brightest bulb on the Christmas tree. It will go high, I expect like a sqare wave, and then go lo, I expect, like a square wave, but not lo to zero, lo to somewhere above zero. I haven't done this experiment -yet-. I busy with my chainsaw maintenance at the moment ( 36 cc 2 stroke ). And when I'm done with the chainsaw, I've got a carb on the 4 stroke snowthrower that needs a rebuild. busy busy. Lg I agree with you that pulsed DC is still DC. And that varying DC is not AC in any respect. Some of the better battery chargers of a few years ago DID impress an AC component on the DC intentionally for just the reasons you mentioned. I have had occasions to leave batteries in vehicles or in storage for long periods of time, but was aware that cheap trickle chargers often supply too much current. It is well documented that even new batteries kept on this type of trickle charger will be damaged by this sort of thing. I insert a small 12v lamp in series with the charger lead to limit the trickle to a 'bias' situation when I have to leave a battery for 1-3 months. It has worked for me. (I choose the lamp wattage to limit the charge to a few hundred milliamperes maximum.) > Periodicity, frequency, has nothing to do with the definition of > *pure.* <munch> You can twist in the wind and tap dance all you want, no skin off my nose. > Now you deserve a headache. I got plenty on my way to a Master's in electrical engineering. >> Periodicity, frequency, has nothing to do with the definition of >> *pure.* [quoted text clipped - 5 lines] > >I got plenty on my way to a Master's in electrical engineering. It seems you need a refresher course in electronics 101. I know whereof I speak, having real field experience on the order of over 40 years. If I had it wrong, I wouldn't have been gainfully employed for all that time, solving real problems in the real world, instead of playing with a calculator. Good luck finding an employer. Lg >There is such a thing as DC with an AC component. No, that would be AC with a DC component. >>There is such a thing as DC with an AC component. > >No, that would be AC with a DC component. some of you guys are beginning to give me a headache maybe its the alzheimer's kicking in. AC with DC offset Loren Eggert BS CompE Purdue University > maybe its the alzheimer's kicking in. AC with DC offset > Loren Eggert > BS CompE Purdue University Unfortunately, I used that terminology also. AC impressed on DC is just adds a ripple to the DC, right? Some battery chargers used half wave rectifiers, others full wave, but there was no need to filter the ripple for battery charging applications. If one allows a little leakage during the cutoff cycle of a halfwave rectifier, then the effect is to have a greatly displaced alternating current, but one which may be largely in one direction. For example, you could have 99.9% of the current flowing in one direction and 0.1% in the other direction. Not 'pure' direct current, but approaching it on a practical basis. This supposedly helped prevent polarization at the electrode surfaces and improved the charge. Am I completely off base? >maybe its the alzheimer's kicking in. AC with DC offset >Loren Eggert >BS CompE Purdue University What does your doctor say it is. I don't give a damn what you call it, it's the same fuckin thing. Would you like a Bacon lettuce and tomato sandwich or we also have the letuce bacon and tomato sandwich and for a little more money, you can get the tomato bacon and lettuce sandwich. yer fuckin nuts. stay at the university. The real world will gobble you up alive. Lg First off, you should post the type of battery. Marine 'gel' cells are really rare. Lead acid spiral cells like Optima are much more common. Then you need to go to the maker's website and find out the 'proper' way to charge it up. Most 'gel' cell batteries will up and die if overcharged. If you have the time, a slow low charge is always the best for pretty much any automotive battery. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's > Hi. > [quoted text clipped - 14 lines] > > please advise > First off, you should post the type of battery. Marine 'gel' cells are > really rare. Lead acid spiral cells like Optima are much more common. Ouch, that one hurt my brain too! :-p > > First off, you should post the type of battery. Marine 'gel' cells are > > really rare. Lead acid spiral cells like Optima are much more common. > > Ouch, that one hurt my brain too! :-p Yup, I should have asked which 'brand' of battery, not type I know. Caught it on the second read, thanks. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's sorry guys to butt in, but i am still confused with the original question./ Should I charge my battery slowly at 2amp over several long hours.. or charge it fast at 10amp or 15amp? >> First off, you should post the type of battery. Marine 'gel' cells are >> really rare. Lead acid spiral cells like Optima are much more common. > >Ouch, that one hurt my brain too! :-p What brand of battery is it? Some 'gel' batteries will die very quickly if charged too fast. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's > sorry guys to butt in, but i am still confused with the original > question./ [quoted text clipped - 6 lines] > > > >Ouch, that one hurt my brain too! :-p Hi thanks for the reply its a deep cycle Gel battery. made by Napa Auto parts the only number i see stamped on the battery that might resemble a model number is " TYPE AGU1" >What brand of battery is it? > [quoted text clipped - 14 lines] >> > >> >Ouch, that one hurt my brain too! :-p >Hi thanks for the reply > [quoted text clipped - 4 lines] >the only number i see stamped on the battery that might resemble a >model number is " TYPE AGU1" What will happen with a *smart* charger when you use hi current on a gel cell, is it will feed hi current in spurts if you select the AGM, GEL CELL switch position. If you select low current it charges continuously. At say around 2 amperes. How do I know? I measured the f*in thing. That's how I know. It ain't theory, it's the way the thing works. So you can spend $16 at WalMart, and buy the Vector 2 amp smart charger, rated for 2 amperes, and it will first read the state of charge, then begin -forcing- 2 amperes through the battery, and when the battery is up to voltage, indicating full charge, it turns itself off. So go to Wally world, part with the $16, and your problems are over. Model VC080 It looks like a little brick, with no buttons on it, just a cord going to the battery, and another going to a wall outlet. Lg My only experience with gel batteries were 6 volt ones and they had to be trickle charged. I would only do that until I phoned Napa and asked them about it. If they don't know then I still figure better safe than sorry. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's > Hi thanks for the reply > [quoted text clipped - 23 lines] > >> > > >> >Ouch, that one hurt my brain too! :-p Your battery will like you better if you charge it slowly. 2 amps is better than 10 amps. No comment on whether DC with an AC component is "pure" DC or not. I do have a little Shumacher charger that I am quite impressed with, and I also have a tiny little "transformer lump" charger that cost a bomb and is specifically designed to charge gel cells. It charges at 14.5 volts until the battery is charged, and then goes to 13.7 volts for long term storage. Judging by it's size I would be very surprised if it can charge at more than half an amp or so. Brian > sorry guys to butt in, but i am still confused with the original > question./ [quoted text clipped - 6 lines] >> >>Ouch, that one hurt my brain too! :-p > sorry guys to butt in, but i am still confused with the original > question./ > > Should I charge my battery slowly at 2amp over several long hours.. or > charge it fast at 10amp or 15amp? In general, slow charging is better for batteries than fast charging. But as has been pointed out, modern automated battery chargers exist specifically for deep-cycle batteries and will apply a charging profile that brings them up quicker than slow charging without harming them. |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.