Let's see if I understand this correctly.
V3 is higher than. V1. Subsequently, A3 is lower than A1...
??? is this a result of more pressure (v) pushing more Ah's (a) into the bank faster, and thus causing amps to taper faster? (to clarify, both start off at about the same amps, but the one tapers much more quickly).
And yes, I see that even at ~ 118 amps charge current, per the 180 Ah's needing to be replaced, amps did indeed begin to taper immediately. So yes, it stands to reason a 180 Amp charge current would taper amps well before 50% soc.
And it's finally dawning on me that I have never done a C/2 charge on my bank. The most I've ever done is about a C/5. So I wasn't even considering the effects of such a high charge rate on the time it would take for amps to taper. I mean, I knew there was some effect, but I hadn't seriously considered it within these parameters.
The next thing to consider, I guess, is whether or not amps taper fast enough to stay within that 1:1 ratio of Amps/Ah's discharged.
1/1 amps ratio is hypothetical... ask yourself, at what bulk recharge voltage is the amps used to amps replaced ratio 1/1? There will always be losses in restoring chemical reactions and returning the potential energy in the battery chemistry. There are always some loses due to resistance, although battery resistance is lowest from probably a 35% to 85 or 90% SOC. Lower than 35%, electrolyte is closer to water and makes a poor conductor, about 85%, there's not much element left in the form of sulfur, to be absorbed back into ionic state as Sulfuric acid, it takes tremendous energy and losses to get a battery back to 100% SOC. Which is why it's best done on the grid, at low voltage and low amps, something that is not a luxury for the most part, daily, while off the grid. Hence the once every 10 to 14 day EQ charge session after top off, at a full 16.0V
Thanks, Niner, but I (we) are trying to determine whether or not using a higher charge rate, i.e; using BFL's mega AMP approach, is resulting in increased sulfation/stratification. SMK has expressed his concern that such a fast replacement of Ah's does not allow for sufficient cleaning of the plates.
I, for one, think this is a very reasonable concern on smk's part, and believe it is deserving of further investigation. That said, I have yet to see any evidence to support such a notion. But then again, I read an interesting article this morning that mentions the 'Amp Hour Law' which suggests limiting Charge Current to the amount of Amp Hours needing to be replaced.
So, for example, a 200Ah bank, at 50% dod, should be charged at no more than a 100a charge current. And as Ah's are replaced, the charge current should decrease accordingly. So, by the time the bank is at 20% dod, the current should have tapered down to 40a max.
Of course, this cannot be accomplished using any power supply / smart charger that operates in a constant current mode from 50-80% soc. It would require a single stage dumb charger, with a particular max amp output, set to the appropriate voltage, to best approximate such a charge profile.
A charger with more amps to give, is designed to be scaled to the amount of amp hours you have on your complete battery pack setup. It should be a standard ratio, perhaps somewhere between C/5 and C/7. Or even C/10. It stands to reason that the slower the charge rate, or the bigger the battery pack AH in relationship to the amps of the charger, the less resistance will be measured by the charger before it shifts out of "bulk" mode, where all the "easy" charging takes place. When resistance gets high, at a given voltage, increasing voltage is the easiest way to overcome the chemical reaction resistance to force the chemical reaction of putting sulfur back into solution.
I would think that a high and fast bulk charge rate at C/5 will consistently bump into "the wall" faster and get out of bulk charging mode at a lower SOC, consistently, if done at 14.4V like on a Progressive Dynamics charger. The Iota takes it to 14.6V, with the little cheater wire loop in place. All the charge controller manufacturers are worried about liability issues caused by The Least Common Denominator that buys their product pre wired in to their new RV unit, and the propensity of FAIL and to not RTFM when they are new owners.
People drive cars their whole lives and don't understand battery charging principles, or discharging principles, or need for routine maintenance. The dumbing down of americans and the low standards of education will make this worse and worse, the need to protect stupid people from themselves. We have a whole new generation of adults that take no accountability for their actions, or inactions, in life.
In general, there is no Statute of Limitations on Stupid... it's a life sentence.
A RV is a whole bunch of systems tied together and integrated, of which it requires the skills of home ownership to maintain, though being 12V some of the skill sets are different than being hooked up full time to a utility company. Cutting off the pedestal at the RV park and going dry camping is cutting the umbilical cord. It makes you responsible and independent to have to learn all that you can to take care of yourself. That most charge controllers are engineered to be 13.6v power supplies tied to the grid all the time means that if you go off grid, time to charge and keep your batteries healthy on a daily basis requires a different approach and different requirements and different voltages from your charge controller. It requires more volts, the amps will follow, as the batteries chemistry and resistance will allow.
In summary, are you off grid or off the power pedestal?
1 = No= 14.4V bulk charge is fine, 13.6V maintinence voltage is fine, since you are plugged in 24/7, and you have the hours at low voltage continuous to top charge your batteries. Battery size, shape or electrolyte to lead plate ratio doesn't matter, you are on the grid and have charging capacity 24/7.
2 = Yes = 14.8V minimum bulk charge rate should be fine if you have good batteries that have a high electrolyte amount and level to amount of lead plates ratio... ie 6V GC-2's
3 = Yes = 15.0V or maybe up to 15.3V bulk charge rate. This is conditional... it depends on the size and shape of your battery, a poor shape, poor design due to other parameters such as space requirements, or designed for cars, or boats, or the confined space of floor sweepers, ie the Trojan T-1275, or the US Battery Screwy 31.
All of the batteries in group 3 are specialized batteries designed around other more important parameters. They require higher voltage to "stir' or bubble slightly the electrolyte to get rid of stratification of acid, or to expose and churn the electrolyte so that fresh low density acid that can take on more sulfur from the plates is exposed to the sulphated portions of the lead plated. The higher voltage creates a "churning" effect on the electrolyte, homogenizing the whole mix so that more sulfur can be taken on. A little bit of heat, in the form of amps lost during charging, is the goal. Not a lot of heat, not gross "boiling" of the electrolyte, but just a little heat, to cause the hot electrolyte to rise in the cells, and the cold electrolyte to sink.
Clear as mud, right? Hope this helps, find out which group of campers and battery requirements and chargers you are in.
If it is true, 'speed charging' leads to lower sg readings, I would definitely like to see the evidence. My experiences with my own batteries. C/7 charging doesn't get my SG any higher than BFL with his fast charging. I've even charged at C/5. The best I've seen was 1.265 (C/7) with it mostly hitting 1.260 or a bit lower. I've been using BFL's charging methods since I got my batteries. I've tried the converter only method with 3 different models. My batts are pampered big time. Doesn't work for me. YMMV.
A week of camping with the PD 9245 in winter, and the Trojan Scrubber battery, running solo, pulling 40 amps amps a day, had me at one cell at 1.250, and the rest at 1.260. My idiot gauge always said I was 2/3 charged, as soon as the generator was turned off. Voltage was about 12.62 to 12.68 with the surface charge removed. With the Mega Watt, 12.73 is pretty common. SG is up 10 to 15 points also when using the MegaWatt at 15.0V. Since I see only 50% discharge cycles allowed, going from 50 to 90 to 50 to 97% adds about 14%, or the battery ends up at 57-97%, is my guess, hypothetically.
As landyacht318 found out 15.3 doesn't seem to hurt a thing on his Group 31. I don't think the T-1275 is much different. GC-2's are just much more efficient at charging back up quickly, with less effort, baby sitting or hand holding. Some shapes and designs need a little bit of brute voltage to get them topped off while charging, others, GC-2's, maybe L-16's too, seem fine with running the 14.4V the PD 9245 or 9260 puts out, or if you have big battery banks, the 9280 or 92100 models.
Run what makes you happy, for a charge controller, if it doesn't make you happy, change it, or get a pendant, charge wizard or the IQ-4 for the Iota series. Or spring for the new Boondocker adjustable voltage model that Randy makes over there at Best Convertor.
Few things are as rewarding as apple smoked bacon and mesquite smoked elk. Smoked salmon (actually LOX) is a classic. Yummy!
Spring run Ocean caught King salmon, properly brined and smoked over Alderwood chips. With a dash of Sage honey on the salmon to add just a little sweetness. Heaven!
The Big Chief smoker takes 8 hours at 120V.
RJ, thanks for the clarification.
I don't know how others can keep their batts in shape when their methods don't work for me, so I always wonder if they are measuring things properly or what. It seems the truth is we each have different circumstances we are working within, so different methods are needed.
I do think if somebody else on the forum finds he needs a different routine from what you need, and has some measurements to explain it, that you should take his word for it.Maybe it's about the effect of the difference in charging profiles. If user A uses a charge profile with 15 V and user B uses a profile of 14.4 V, how much is the difference in results? Will user B suffer capacity loss or have to exchange his batteries a month before user A? Will user A have to add .05 ounces more of water over a 1/2 year period? In the grand scheme of things, it may be a very small difference using either profile. What I do know for certain is that I've spent way more time thinking about battery maintenance after joining this Forum. That, IMO, is a good thing.ditto for me too.
I think I get pretty good EQ readings on a funky T-1275 when I use 15.0V to charge for Vabs. I accept, as others do, that it's a Problem Child to get it topped off, and that it needs an EQ job when I get back from a week or two camping trip to really get the lead out of and off of the sulfur that needs to get back into solution as Sulfuric Acid, where it is then ready for some extended storage time. A topped off battery is a long living happy battery when left in the storage yard or driveway.
I think the one my dad had was a Freas, but it's long gone. It had its own box, was well taken care of, rinsed, etc., and in the 30ish years I remember it, it looked like new. In LA smog, nothing short of a sealed bag will keep the ozone off it. I'm on my 3rd cheapie and it's showing its age already
Alright, post up the link to the "buy it now" button, already!
Buy another Eu2000i Honda and a parallel cable kit, and be done with it. 3600 watts on tap, when you need it. Always parallel the cables first before starting either generator. That should run everything on your 5th wheel, though not all at the same time, you might have to juggle some things being off while other items are on. A/C unit and microwave or AC and hair dryer at the same time would be big no no's.
RJ consider that unit sold... I got $30 cash for ya down in Q this winter. And don't say I never made ya happy!
As long as my hand me down T-1275's keep coming for free, I'll pump 'em up with whatever feels handy voltage wise, to massage their guts free of sulphation like a Marine Drill Sargent down at Camp Pendelton for the BUDS program.
PM me an email address at your convenience. I can PayPal you, this will make me a fine birthday gift to myself for Oct 30th.
I don't think it's fair to put that POS WFCO in your old trailer, before selling it or giving it away. Buy a new or used PD for the new trailer, and let the owner of the old trailer keep the original unit that came inside it.
You'll get far better performance if you mount the new PD as close as possible to your batteries, with a short run of thick cable from charge controller to batteries.
well, I'm a hippie, and I can go 3 - 4 weeks on 54 u.s. gallons :)I could use less than that if I didn't shower or take a crap.
I wonder if Canadian gallons get you more for your buck? You wouldn't know it by the price of fuel in Canada.
The key to less crap. is more fiber in your diet. And dropping no wipe tootsie rolls..
Rather than start a new thread since everyone is here.. Any of you battery boys ever used one of THESE ?Nope, it looks like the typical circular counter weighted hydrometers but in a better package.
Francis Freas has made the industry standard glass hydrometer for a number of years. You can buy direct from them, singly here, or buy eight of them plus shipping and give them away as Xmas gifts to your RV buddies.
A little spendy for a stocking stuffer, eh?I dunno, unless my math is bad or comprehension lacking, the eight for $59 + $18 shipping works out to be less than $9 a unit. I don't feel that's too much for you to pay for my Xmas gift, lol. :B
As Mex mentioned, proper tool use with these rubber ended hydrometers involves the rinse cycle. I rinse mine three times when I'm done and put it away in the enclosed battery box, at hand for another use. I'm not tapping away trying to eliminate air bubbles and the rinse may have something to do with that.
The cut sheet that was posted shows that the hydrometer under consideration isn't your garden variety circular job. That looks like a good tool.
My take on it was that only 2 of the 8 were Freas brand hydrometers, the ones shown, not all 8 units?
I think someone with US batteries labeled "Screwy 31's" had to go to 15.3 V also. About time Dometic and others get circuit boards for refrigerators that can handle more than 15.4V without going poof and failing.
Actually Niner, if it is halfway accurate and "easier to use" than a standard hydrometer, I am all for the hydrometer-reluctant to choose it rather than not use a hydrometer at all. I save my sarcasm for those individuals who publicly ridicule hydrometer use in general.
Us fishermen don't get no respect!
Ill post the .pdf on it. Looks interesting tho. My complaints on glass it sticktion(sp), and errant bubbles screwing up the readings. I have the same problem with my floating bulb in the reef tank and finally resorted to a refractometer because nothing was repeatable. In the cut sheet for this thing they say they addressed those exact things as priority #1
Well, if you order one, let us know how well or not so well it works.
Unless force fed... :)
A NA 3L will flow a MAX of 3L...but a forced fed can flow double or
more depending on boost level
Suitcase muffler too? Not sure, I never looked under the truck.
I wouldn't worry too much, a 3 liter motor only flows so much air, and it would be rare for you to be running much over 3000 rpm, usually considerably less. One muffler is plenty for that little low rpm motor.
I am sure that with a boost of 23 psi or + 1.5ATM's, the engineers took that into account, along with all the other restrictions in line, like DPF's, lamba sensors for and aft for clogging and regeneration, resistance to backpressure exhaust side, pre turbo, cat convertor, etc, etc, etc. Muffler is the last in a long line of resistance to exhaust flow, it's a non issue in this design, too much upstream. Dual tips and dual mufflers would be more an appearance package and a metric ton of weight and redundancy.
Someone here should take some time and visit some EE forums where PhD EE discuss this problem and arrive at a conclusion that with some power supplies it can lead to disaster. A 22 dollar power supply is not a Lamda with it's inherent current and feedback protection attributes. I have no idea if a Megawatt design can be paralleled without isolation, but I am not dealing with it or any other PS. Just the 22 dollar unit.
FWIW, when first turning on the Mega Watt, after hooking up to battery first, then starting and warming up the generator, then turning it on, it will draw 40 amps on the amp meter, on a 70% soc T-1275. The amp rate falls off/decays at about an amp a second, until it gets to around the 27 amp mark, or 90% of the 30 amp capability.
At no point in time does the Mega Watt make funny sounds, humming sounds, vibrating sounds or any other unusual sounds during this process. Take it for what it is worth, I am not an EE, just sharing what my observations are, I don't know what to look for or sniff for before the blue electric melt down cloud goes poof before my eyes and nose. YMMV... my experience with the unit, in my particular circumstances, so far, has been flawless.