Niner Bikes Brought Up An Excellent Criticism Point

[MEXICOWANDERER]

I was being remiss in not saying with the basics, when discussing batteries. To me this is a cardinal error. Forgive me...

Here is a little something I composed last night before my fingers gave out...



SAFE BATTERY CHARGING

There has been so much hyperbole written about “what's safe” and “what's unsafe” regarding battery charging voltage that my head spins. You need to know what voltage level your batteries are at – at rest, when being charged in earnest, or when they are kicking back on a maintenance level voltage. Without a voltmeter reading, you are driving blind. Personally I won't ride alongside a blindfolded driver.

There is no such thing as a “Plug N Play” battery charger or “total hands-off” battery maintenance charging device – plug in, solar, or vehicle alternator. I wish there was one, I would be first in line to buy one.

Most folks go camping when air temperatures are agreeable and not when it's 0 C or 40 C (320F) or (1040F) outside. Batteries are like people. They like hot food to eat when it's cold (higher voltage charging and storage) and a nice chilled salad (lower voltage) when it's sweltering outside. But let's talk about charging voltage and camping. And for crying-out-loud, let's avoid techno babble.

Deep cycle wet acid batteries are similar enough in behavior (oops Canadians “behaviour”) to engine starting batteries, that for charging purposes we can “assume” they will like and appreciate a fairly similar charging diet (voltage). The difference between the two types of batteries is not great enough to be like trying to feed a cat a chef salad. The two types of batteries will love the following charging advice. Remember now, we are talking about charging not float maintenance where the batteries sit in the shade, do nothing but sip cold Coronas for months-on-end.

The point all the so-called experts forget about or miss (intentionally? To make their own advice seem more important than it really is?) is that hundreds of millions of high powered battery chargers have been already proofed out over the last 80-years. A billion flooded lead acid batteries taken care of with these “chargers”? I don't know the exact number but regardless, it adds up to one hell of an impressive number of batteries.

The Secret? Tah-Dah! It's the alternator in your car, pickup, or motorhome. When you start your rig, the alternator and voltage regular supply charging energy right up to the limit of the alternator's amperage rating. Some alternators have impressive charging ability – 130 amperes and even more than that.

What does this mean? Let's use a motorhome as an example. One modern unit with a 130 amp alternator and a pair of group 27 house batteries. When you start the engine the alternator goes to work. From experience I can tell you a group 27 battery will gobble around 45 amperes of power when it's discharged. So the pair will consume 90 amps. In effect when you start the engine the batteries will have as much power on their plate as they can possibly use. Yes batteries can be overcharged. But your car's alternator is throttled by a control device called a voltage regulator. The voltage only goes “so high” and that's it. The alternator stops charging at this limit. To be blunt, that exact limit in numbers is referred to as the Voltage Regulator Set Point.

So what does all this have to do with the price of dates in Qatar? Think about it. You start your engine, and the house batteries get charged right to the set point of the alternator voltage regulator. There is no self-imposed limit to the charging amperage. The batteries are “offered” the voltage at the set point of the voltage regulator and the batteries automatically consume just so-many amperes. As far as cars go, this magic charging process has been around for 90 years or so.

Keep your thinking hat on please. Do alternators cause fires, boiled batteries, flood, famine and disease? No. Start your engine with depleted house batteries and drive for a dozen hours on the interstate. What do you imagine is happening all those miles? In tens or millions of cars? Over a ninety-year period. Yes alternators can fail and cause problems. I can have a heart-attack and that will pretty much screw-up my plans, too.

Automotive alternators are controlled by a voltage regulator, the brains of the outfit. Most “regulators” operate in the 14.0 to 14.4 volt range. Thats four-tenths of a volt variation. Remember, tens of millions of cars, and perhaps a billion batteries have been baby-sitted with this for more than 90 years. Yes, there were 6-volt systems back then and generators and they operated on half the voltage. Sue me. It's exactly the same thing. Each cell of the battery saw the same voltage back when San Francisco shook horses whinnied and buildings burned as they see today, this very second, in tens of millions of motor vehicles running around occasionally smacking into one other.

Can we therefore assume a battery that needs to be charged can have 14.0 to 14.4 volts INSTANTLY applied to its terminals and be a happy camper? Remember we are talking about charging and not float maintenance or equalization. Let's not play Three-Card-Monte word-games here. Yes, we can not only assume we can, we can (and will) take this assumption to the bank!

Yeah you got some discharged batteries and you need to charge them. Why not supply them with 14.0 – 14.4 volts? Instantly? “But I have eight golf car batteries!” you complain. Tough! That's enough of a battery bank to have an ability of accepting a few hundreds of amperes charge rate when the bank is hungry. Want to recharge the batteries as fast as safely possible? Give them 14.0 – 14.4 volts, and stand back. Yes, it's like feeding a 6'6” 16-year old. They'll open the refrigerator door, tilt it and let everything slide into their mouth. Like that sliding food, buying enough charging ability to instantly achieve 14.0 – 14.4 volts ain't cheap. The point here, is 14.0 to 14.4 volts recharging is safe regardless of the amperage. One millionth of an amp – one million amps, it's all the same when the voltage is controlled.

Why is this important? It's important when camping. Generators, generally, are like your unemployed brother-in-law, most of the energy they use does nothing more than empty your bank account. For a generator to be the least useful, when you start it, it should have the ability to immediately bring the voltage of the batteries to 14.0 to 14.4 volts and stay there. Stay there until the batteries are charged. Or mostly charged. That's another subject. A two thousand watt generator should have to ability to achieve 120 amperes of recharging rate if switch-type battery chargers are used.

When you crank up a generator it costs a lot of money. Money for fuel (only available after you burn 10-gallons more fuel to go get it). Do you love wasting time driving to and from a gas station? Or paying four dollars a gallon for generator fuel of which more than ninety percent is normally wasted? Like to listen to the 80 db “purr” of your generator for hours on end? How about changing oil, or shelling out a ton of money to replace a worn-out generator? If you don't present 14.0 to 14.4 volts to your battery bank right off the bat, your generator is laughing while your batteries are chirping to be fed faster. Even a “financially comfortable” RV owner should get quivering knees at the thought of wasting that kind of money on running a generator inefficiently.

Any individual who wishes to argue against the points brought out in this article had better start off by running around the world screaming “You Can't Do That!!” at several billion automotive charging systems, before complaining to the author.

Forget so called “rules” printed by battery manufacturers. Their engineers live in a dream world. Their rules are for batteries that can be recharged at “leisure” connected to an electrical grid. You live in the world of four dollar a gallon fuel that is a long way off. It is ummm.... (is the word “not wise” politically correct enough?) not wise to spend four-hundred dollars plus trying to extract twenty dollars worth of “extra-life” out of a pair of RV batteries by following battery manufacturer's “rules” for achieving “optimum life” out of a battery. If you have time and money to burn to try and meet a worthless goal then go for it.

But if you're smart. When you recharge, you present 14.0 to 14.4 volts to a discharged battery INSTANTLY. The issue is you may have one hell of a large battery bank and need lots of amperage to meet this specification. Multiple chargers needed. Is the generator “Big Enough”?. “Which is worth more to me: Not running the generator or putting in more recharging ability? Do I wilderness camp enough to make this worthwhile?” Those are “smart” questions to ask and arrive at an honest answer.

But needlessly running a generator for hours on end, is dumb, dumb, dumb.

And it's all up to you, now that you know facts...

[NinerBikes]

33 Amp Power Supply as a battery charger.

FYI, Mexico Wanderer's inspiration for this post is in reference to this thread.

[landyacht318]

Excellent write up Mex.

Your theoretical depleted 27's amp draw from a 130 amp alternator nearly exactly matches my observations.

My voltage regulator allows 14.9v, but will prematurely drop to 13.7 or 13.9. Where as it might have taken 65 amps to hold 14.9v, it only takes 13 amps to hold 13.7v. The VR is in the engine computer so I am not going to worry about the premature 13.9/.7. Sometimes just flicking on the lights or blower motor briefly will ratchet it back up to 14.9, and other times it just seems to go back up there for no apparent reason. So be it.

My depleted batteries always seemed to respond well to this Massive Morning alternator blast of bulk current. Much better than if my solar alone were to take and hold them in the high 14's / low 15's for several hours.

I've seen my current group 31 take 65 alternator amps for about a minute before voltage climbs to 14.9v, but I need to adjust/replace the V belt as it now starts screeching at that level on a damp morning.

Lets not forget the importance of proper cabling from alternator to house bank. I think too many people take power for the house bank from the starting battery, which leaves the OEM charging circuit as the weak link.

Amazing how a fused cable from alternator(+) directly to house bank or solenoid, in parallel to the OEM circuit, allows significantly higher amps to reach depleted house batteries.

I have a circuit breaker on my doubled 4awg parallel circuit. If I deactivate this parallel circuit, current into the battery can be cut by 2/3 with depleted batteries and enough rpm to make a difference.

Perhaps some wish to baby their alternator with thin wiring. Not me. If the batteries are thirsty I'll let them drink through a doubled mcdonalds straw, not a single kinked cocktail straw, and my Current alternator has been subjected to this "abuse" since 2006.

[red31]

NinerBikes wrote:
bulk charging. Which is what we are discussing ONLY here, in this thread.

I thought Mex is suggesting bypassing bulk and get to 14.4 @ the battery and keep it there, ain't that called absorption? The 'curve' part of BFL's ugly curve.

[NinerBikes]

BoonHauler wrote:
I myself think that 14.4 is too low for FLA batts, I'm in the 14.8 temperature compensated camp and at a minimum the C10 rate for amperage.

Damm Mex, I wish I could type like you!!...... :B

I run true deep cycle batteries, the kind with 5% antimony plates, the kind that are considered heavy duty industrial use. Trojan's T-1275. Others have commented, and they are correct, that this particular battery is a bit of a funny or unusual one in it's charging needs.

I go with 14.8V on a Trojan T-1275, and so far, I'm pleased with the results I am getting. Good solar on top of generator and bulk charging in the AM is giving me good results. YMMV, the 6v golf cart batteries seem to do just fine on 14.4V. The T-1275 seems to like the voltage a little bit hotter to get things topped off quickly.


I'd run 14.4v to group 24 DC and group 27 DC for bulk charging. Which is what we are discussing ONLY here, in this thread. Bulk charging, that 50 to 90% "git 'er done" charging you do first thing in the morning, making noise, and burning expensive gas, while trying to minimize time charging, noise, and fuel expenses to do so. ONLY because fuel savings grow faster than the cost of getting another year or two out of your 8 to 10 year old deep cycle batteries on your part time toy hauler RV gizmo. Time is money also. Time spent burning gas charging adds up fast. Babysitting solar panels is a no brainer. Know the strengths and weakness's of both types of charging systems, and play to their strengths.

[NinerBikes]

RJ, one must conclude you are doing something right if you don't need to ever use the warranty feature of your deep cycle batteries. Carry on.

[RJsfishin]

I scanned over all this, then think, if my batts last 8-10 yrs doing what I'm doing, which they do, what do I have to gain by anything more than what a PD converter will do ? When camping, my Honda 1000 and some solar when the sun shines, I just don't get all this. I have other lives, besides babysitting my batteries.
I started a thread one time,...How long do we want our batteries to last.
I think the answer was, "As long as possible"

[BoonHauler]

I myself think that 14.4 is too low for FLA batts, I'm in the 14.8 temperature compensated camp and at a minimum the C10 rate for amperage.

Damm Mex, I wish I could type like you!!...... :B

[NinerBikes]

Guilty as charged... the title shall read "Power Supply units as Lead Acid Battery Chargers for Dummies".

It's Ok to know you know just enough to be dangerous... Provided you know what you don't know... and know when to ask, when you don't know.

On the other hand, it sure is nice to find a way to beat the Nanny State mentality so many other designs incorporate that are nothing more than compromises of half aZZEd attempts at something that really needs and loves a 100% charge for it's longevity and well being.

[time2roll]

MEXICOWANDERER wrote:
You need to know what voltage level your batteries are at – at rest, when being charged in earnest, or when they are kicking back on a maintenance level voltage. Without a voltmeter reading, you are driving blind. Personally I won't ride alongside a blindfolded driver.

There is no such thing as a “Plug N Play” battery charger or “total hands-off” battery maintenance charging device – plug in, solar, or vehicle alternator. I wish there was one, I would be first in line t0 buy one.

A good solar controller will get you 99%+ to nirvana.
Nothing in the grand description is missed. Just add some distilled water 😉

[azrving]

In fact when we used the term boil it was more of a joke than anything. We would laugh and say bring to a boil and simmer for a few hours. Everyone knew what the guy meant. Sorry if its an issue to anyone. I didn't get the whole post at first, I'm not a battery expert as I was one of the main people in our shop working on the DC to AC 3 phase brush less motor systems used in Hyster trucks. We also ran some old separately excited brushed motors. I know that batteries need a proper charge, equalization, water after charging etc. They put the guys who couldn't fix the trucks in the battery room so I didn't really deal with them much. I also agree with those who think good multiple stage battery chargers should be used to charge deep cycle batteries.
I need to research all of this stuff more so I choose the right components to do what I want. NO, BFL113 I dont want to buy your old stuff. 🙂 I agree with Mex on the quality issue he has posted elsewhere as we did run Crown and they were very good. Hopefully I can learn enough from the people who have been doing this a long time that I put together a decent set up.

[wa8yxm]

pianotuna wrote:
Hi,

They don't boil. They gas. It is a huge difference.

Piano, you know it is gassing, I know it is gassing, but folks who work with batteries as the Fork Lift repair guy did still call it "Boiling the battery" I know this too cause.. Well I get around I guess.

It looks (Physically) like boiling so that is what they call it.

And I wondered how much those fork lift things weighed. True story: Borrowed one once for a ham club's field day, Took #1 in the state we did that year.. Used about 10% of the charge on the fork lift battery.

Automotive batteries do not have such a problem with stratification cause of the way they live, Bouncing down washboard road de-stratifies them as easily as boiling will.. And there are several other compromises made in "Maintenance free" designs. that result in more frequent replacement, but if you are paying by the hour, lower cost.

Many myths about batteries.. Few stand up to research.. Alternators (And generators before them) were/are both current and voltage regulated for example. They just do it differently. Some of them are rather advanced in how they regulate, some are not. Some could sense the difference between charging current and total output and adjust generator (This was a generator) output to limit charging current or total output as needed (you do not wish to charge too fast or burn out the generator). and this was back in the 1950's.

IN this case though I'm not researching.. I owned such a car.

[BFL13]

Mex, I do not have that kind of charger that can do that! Maybe an alternator with a fancy regulator like they use in big yachts?

Gas is $5 here but I don't really care how much the Honda gen uses to do a 50-90 on my batts in two hours. I think I can do three on a tank costs $12 to fill, so that would be about $4 each roughly. That means if I could cut down to an hour vs two, that would save me $2 a 50-90.

In our case, four days is two 50-90s and we do that say five times Oct-March, then we go on summer routine Apr-Sep when we might use the gen another five times. Varies. Been here a month now with solar and had to use the gen twice the first week, then not since. Anyway, call it fifteen 50-90s a year. That's $60 a year in gas for the Honda.

This is not Mex's situation and does not require spending big bucks as a one-time shot to save gasoline while full-timing where it is hard to get gas.

IAW as always, it is situational what is "worth it" to each individual RVer. What Mex shows is that there are indeed options available not often mentioned in the usual battery blurbs.

[MEXICOWANDERER]

BFL13, when enough amperage is presented, a depleted battery can jump to full regulated voltage -instantly-.

Amplification. Your batteries get depleted to the point where they are the most charge sensitive. Charge receptive.

Keep feeding them increasing amounts VOLTAGE LIMITED amperage until such time as voltage rises to the magic set point of 14.0 - 14.4

I regularly hammer my discharged 2-volt cells with 24 volt amperage approaching five hundred amperes and they respond by instantly going to 28.0 volts and staying there until they charge.

If generator run-time is not an issue, then this is a moot point. If you have connection to the Tennessee Valley Authority power grid this is a moot point. If you have a large generator laughing at a piddly charging system then this is not a moot point. Do the math and figure out how much money just in fuel one single battery charge costs you. Then factor in the kWh available by the batteries for that money. Surprise! Please don't have a stroke when you see the stupendous cost of each kWh. Oh forget about trips for fuel, wearing out the generator and insignificant stuff like that.

Having an MBA, it conflicts with my MEE. An engineer whose motive is to do the most with the least amount of money. I've run the numbers on this area so many times I see them in my sleep. I wish I could do this with solar. But the damned clouds keep getting in the way. Having a thousand dollars worth of food go bad in the freezer, or Jesús' four thousand in lobsters go bad is not an option. "The Store" is a seventy mile round trip.

When that Kubota starts, it is allowed to warm up for three minutes, then it grunts. No free rides. I don't have time, energy or money to play games battery charging. Diesel is almost (four dollars a gallon) down here too. The nearest gasolinera (Pemex Station) is a forty-mile round trip.

[BFL13]

I missed whatever set that off 🙂 but good points on generator charging to get the job done with least gen running time.

I am not sure what is meant by "hitting them up-front" with 14.4v. I use a charging rate of about 25-30% with chargers that go to 14.8, but the batteries just can't jump that fast in voltage--it takes time with amps going in to get battery voltage to rise.

The higher the charging rate, the sooner you get to 14.4v, but at a lower SOC. To have any constant amp stage your charging rate needs to be under about 33% or amps will just taper from the beginning if you start with batteries at 50% and a huge charging rate. (Might not be anything wrong with tapering from the start, but I like to see at least a few minutes of constant amps first--makes me feel things are going along properly. Feeling is an emotion though, not science)

As to practical equipment limits while camping, your generator can only run so many watts worth of chargers. You can get more amps by using power-factor corrected chargers instead of the more common non-corrected types.

My Honda 3000 gen can run 130amps using non-power factor corrected Vector chargers but pops its breaker at 135a I can use my PowerMax PF corrected 100a charger plus some Vectors and now I can make 150a. You have to start somewhere picking your equipment.

If you start with your battery bank of say 460AH, and you decide you will charge at 30% charging rate (138a) then you can get enough chargers to do 138a and a gen that will run the chargers. From above that would be a Honda 3000. A 2000 isn't enough. Be ok for a bank of two 6s though.

My goal is to complete a "50-90" in two hours. I can do that with 130a on 460AH. I have had 6 batteries in a bank of 720AH (approx.)and used just the 100a charger plus a 40a Vector for 140a which is a 19.4% charging rate. That runs me over the two hours, more like 2.5 hours, but my Honda 3000 is the limiting factor, which is the point Mex was making.

You need enough gen to run enough chargers to get your charging rate that will meet your time requirement. (My two hour requirement comes from local provincial parks which have gen hours from 9-11am and 6-8pm and I do the recharge in the morning)

Mex gets his requirement from gas prices to run the gen. Others want the noise to stop as soon as possible. Or all of the above.

I have an ugly graph you can search for, which gives the times to do a 50-90 for various charging rates. From that you can design your perfect set-up.