NOT Tesla Batteries

a. I am not going to build the charging system for the main system, there i s too much out there that is too far beyond me. I am not learning to do sof tware and USB interfaces and all that shit. So that part of it is settled.

e a bit more efficient obviously, the wire gauges are half what they would be at 12, and going to higher voltages really gets into diminishing returns . It might not even be Tesla batteries, there are alternatives. Plus he alr eady ordered the PV panels and is next going to deal with the mounting and the tilting mechanism, which is not my job.

tor for that and have recommended that he get a regular lead acid battery f or that, preferably deep cycle.

ator to put out something like 14.8 volts, can I just dump that into the ba ttery with no filtering ? AND, would it be advantageous to do so ?

g puts out an AC current to the battery and that somehow makes it better. T hey claimed it knocked the sulfides off the plates or whatever.

fter) the aid of the storage battery of course.

ng to put them at about 25KHz to make sure they're inaudible. That wiring w ill be all over the place so I think that is a good move. However this char ger deal is going to be stashed in the back of this thing and I can use 25H z, 30Hz, 60Hz, whatever.

er will limit current to a reasonable level and shut down at what, 13.8 ? W hatever.

better charge. With an old battery this would require the periodic additio n of water but on a maintenance free newer one it can take it. I've had car s that charged at like 14.3 and they were able to start but not much else. But then my van, well I lived with the olman and we couldn't smoke pot in t he house. This thing charged at about 15.8. We sat in that thing (I had eas y chairs n shit in there, house speakers, this was the young Man cave) for six hours partying and it started up just fine in the morning. We had the i nterior lights on and the stereo, used the lighter. Other vehicles it seeme d if you left the headlights on for three hours you needed a jump start. S o I want a nice healthy charge on that battery.

want to get as close as possible to being able to handle that, but if a bli zzard there will be practically no solar coming in. So one of the enhanceme nts will be possibly to charge the main batteries off the engine alternator . We intend to install a second alternator for this. What's more in the col d the vehicle heater will assist whatever else goes in there, propane of co urse.

rge it with pulsed current ? Is it bad ? Does it simply not matter ? That i s my question for today.

Speaking from relative ignorance on pulsed charging, but I have never seen any indication that pulsed DC would harm a lead acid battery. In fact, I h ave see reports that in general, pulsed charging of batteries can be good. It seems the pulsing provides some time for the electrolytes to diffuse an d prevent some of the concentrations from causing problems in charging.

I will say the voltage you charge the battery to, and that is the battery v oltage, not the voltage at the other end of the cable, is well documented a nd is a function of battery temperature. Overcharge and you will harm the battery, maintenance free or not.

Rick C.

- Tesla referral code -

I'd say no. just tap the 24V stack at 12V and take the 12V from the lower battery.

then fit a buck converter with feedback to maintain the lower battery at the mid-point voltage of the whole stack.

This also gives the option of running mis-matched batteries in the stack.

--
  When I tried casting out nines I made a hash of it.

• Not claim..more like fact. The idea is the charge/discharge current chemically tears apart the sulfides, so they can be formed into chemically useful lead sulphate. Sulfide is used to describe any of three types of chemical compounds that contain sulfur. Sulfite is sulfur dioxide, or SO2.

• Re-think.. There may be MORE light available during a blizzard than a foggy day.

• Limit the pulsing and you are OK. Just like DC chargers run between constant voltage and constant current, one puts limits on those values. A highly sulphated battery will require a large voltage (i have seen up to 100V needed) to get a decent current,so think a (semi) constant current AC source. A variac, and capacitor in series for the AC charge/discharge component, and a diode across the battery to limit overall discharge will do the job.

Perhaps pick C/20 for slow,normal use; add voltage limit when charging rises to nominal value, NO limit if baaaad battery.

Pick a reputable battery vendor. Go to their website and look up the specs on the battery you'll buy. It will give you temperature compensation curves and maximum charge/discharge currents. Conventional wisdom suggests that you want to use no more than half of the rated capacity. Multiply that by the bad weather you need to ride out. By the time you're done with that, you'll decide that you can't afford enough solar panels to provide excess peak current to the batteries. But you do need to limit the total charge according to the manufacturer's curves. Automotive alternators provide pulsed current at varying frequencies. If it were me, I'd provide some filtering. Makes it easier to instrument.

Pay careful attention to the battery configuration. Little things matter.

Make sure you're measuring the voltages right at the batteries. If you have a bunch of batteries in parallel, you might wire them up like this:

• --------------------- B B B B B

- ---------------------

But those resistances add up to make a significant difference in currents per battery.

Might be better to wire them up like this:

• --------------------- B B B B ---------------------- -

Batteries don't charge on volts. They charge on current. Volts is a result. You MUST build (or buy) a MPPT solar charge controller. Solar panels are closer to current sources where it matters. MPPT modifies the pulse width to achieve maximum average current, then throttles back as the target voltage is achieved. We used a shunt regulator to limit the charge voltage, mostly because the wind generator component got very unhappy when you unloaded it in a high wind.

You don't have to use exotic algorithms. Perturb and observe is plenty good.

It's trivial to achieve on a PIC processor, but I expect that an arduino would be a better choice today. Add bluetooth and you can control/log on a smart phone.

Most interesting system I'd ever heard of used solar to disassociate water into hydrogen and oxygen. Storage was a barrel full of water with a concentric inverted barrel inside. The gas raised the smaller barrel. You put a few bricks on top to regulate the pressure.

They used Hydrogen Fuel cells for electricity and burned the Hydrogen for heat and cooking.

Such a system has significant risk of explosion, but it seemed to do the job without a lot of batteries.

More info than you ever wanted to know:

--
Regards, 
Carl Ijames

Not to be an asshole, but I am top posting to reply to all. Thanks.

You admitting that is noteworthy...

good..."

That's pretty much what I've gleaned over the years. a car alternator for e xample is not filtered in any way and it is pretty much pulsed, though sine type waves, at anywhere from like 2KHz to who knows. I was kinda thinking that a lower frequency would be better, but I am not sure of that. I must a lso admit ignorance on the subject but it looks like I won't be ignorant fo r long.

Yes, I heard about that. But a car now, the way it thermally tracks is in c old weather it will apply a higher charging voltage, once it all warms up i t tapers off some. The reference voltage is not the output, it is off a sep arate set of tops of a three phase full wave bridge. so it is also partly c urrent and partly voltage regulated. I thin it would maybe be a good idea t o charge like that, since it has been working for the last forty years.

battery. "

You're talking using a battery balancer. I am not so sure I want to do that . The balancer, as efficient as it may be it actually just partly shorting out the top battery. I think with the batteries in parallel we would get mo re capacity in the end. The ONE regulator would be doing the charging, the batteries, especially more than one would do most of the filtering. I dunno , it IS an option but I am not sure it is right for this project.

The idea is the charge/discharge current chemically tears apart the sulf ides, so they can be formed into chemically useful lead sulphate. "

Sounds like we just saved the cost of a choke. The only problem is the peak current of the chopper(s). Actually just one 100 amp MOSFET should do it, no ?

oggy day. "

Re-think is right, just what wavelengths of light do these things run off o f ?

But that should never happen right ? Or at least for a long long time...

it were me, I'd provide some filtering. Makes it easier to instrument. "

I think I can pick that up anyway. If there IS, which seems to be, an actua l advantage to pulsed current I will deal with it. Might have to do some m ath but if anyone could do it it would pay minimum wage. Just a resistor an d a filter will give me a smooth enough voltage I think, and a series resis tor, low value as it may be would serve to set the maximum current. I just want to keep it down at like 0.1 ohm. We do not want to waste power. So wha tever voltage I get would have to be scaled by amplification. No sweat.

to disassociate water into hydrogen and oxygen. "

HA, one day a friend of mine comes over with a water separator, but it had the H and O2 unseparated. Could have blown up the house. Edumacated him a b it about making like tubes or something to collect the gases of each electr ode separately, and then they are pumped into tanks... But the house did no t fly to Kansas so we OK.

Right up my alley.

I will be reading that soon. Probably be back with questions. Damn answers, more than half the time you get an answer and you got at least a new quest ion. Dammit.

Thanks all. I think we are going to git-r-done.

e good..."

example is not filtered in any way and it is pretty much pulsed, though si ne type waves, at anywhere from like 2KHz to who knows. I was kinda thinkin g that a lower frequency would be better, but I am not sure of that. I must also admit ignorance on the subject but it looks like I won't be ignorant for long.

cold weather it will apply a higher charging voltage, once it all warms up it tapers off some. The reference voltage is not the output, it is off a s eparate set of tops of a three phase full wave bridge. so it is also partly current and partly voltage regulated. I thin it would maybe be a good idea to charge like that, since it has been working for the last forty years.

I would not use anything about the way a car charges a battery to be an exa mple of doing it "right". While a typical car battery lasts some four year s or so, properly maintained lead acid batteries last 20 years. I worked f or a railroad once and they had batteries in service for at least 20 years before they would find need to remove them.

In particular, you should actually measure the temperature of the battery, not the ambient temp. The battery will get warm from use.

er battery. "

at. The balancer, as efficient as it may be it actually just partly shortin g out the top battery. I think with the batteries in parallel we would get more capacity in the end. The ONE regulator would be doing the charging, th e batteries, especially more than one would do most of the filtering. I dun no, it IS an option but I am not sure it is right for this project.

I'm not sure why that would be better than just a 24 to 12 volt converter. Isn't it really the same thing?

lfides, so they can be formed into chemically useful lead sulphate. "

ak current of the chopper(s). Actually just one 100 amp MOSFET should do it , no ?

Of all the battery chargers I've opened up, I've never seen either a separa te choke or a capacitor in them. They have a transformer, a diode or two a nd a big honkin transformer. I suspect they only put out pulsed DC. I've never scoped one though.

foggy day. "

of ?

I'm not sure that is very relevant. Even if you get some light, it won't b e much. I've been snow bound for a while, but I've never been in a week lo ng blizzard though. I have been in more than a week of heavy overcast thou gh. In fact, I think this past year we had so many overcast and rain days that they outnumbered the sunny days. Mid-Atlantic states.

f it were me, I'd provide some filtering. Makes it easier to instrument. "

ual advantage to pulsed current I will deal with it. Might have to do some math but if anyone could do it it would pay minimum wage. Just a resistor and a filter will give me a smooth enough voltage I think, and a series res istor, low value as it may be would serve to set the maximum current. I jus t want to keep it down at like 0.1 ohm. We do not want to waste power. So w hatever voltage I get would have to be scaled by amplification. No sweat.

Averaging won't give you RMS, but if the waveform is consistent it can be c alibrated accurately. It may take a long sample time or synchronous sampli ngs to minimize artifacts of not having whole periods in a single average.

d the H and O2 unseparated. Could have blown up the house. Edumacated him a bit about making like tubes or something to collect the gases of each elec trode separately, and then they are pumped into tanks... But the house did not fly to Kansas so we OK.

s, more than half the time you get an answer and you got at least a new que stion. Dammit.

Good luck.

Rick C.

• Tesla referral code -
  formatting link

I got sucked into a discussion of Brown's gas by a guy who was generating it to run his car. Free energy...right... So, one night, he forgot to turn off the generator in the trunk. Next morning, when he tried to start it, it exploded the air filter and blew the valve cover completely off. He was undeterred, despite a mathematical analysis showing that he was doing nothing more than spending money to wear out his engine.

This thread is a basic design review. If I were the project manager, I'd be biting my tongue and sending you home with homework... Everything is a tradeoff. Even if more is better for that function, it may not be better than having less here and using that extra resource to make something else more better. Might be overall optimization of cost, time to market, reliability...

If the project is a solar panel with a switching buck regulator to charge

24V lead acid batteries, there are some things that you might not have thought about. Depending on your total architecture, buck may not be enough, but don't worry about that at this point.

The time to think about them is BEFORE you start spending money buying stuff.

The most costly, biggest, most fragile part of the system is the solar array. You want to maximize the number of electrons it produces per dollar/meter/whateverparameter.

So, get yourself a graph of the voltage/current curves for your panels parameterized by insolation level. On each curve, find the point where volts times current is maximum. Put a dot on each curve at those points. Draw a curve thru those points and call it the maximum power line. Draw a horizontal line at 30 Volts...round numbers. Below that 30V line, you get zero output capable of charging the fully charged 24V battery.

At this point, you're probably formulating your response on how I'm full of shit and... Bite your tongue and hang in there. There will be plenty of time to fine tune the numbers. This is the concept phase...just bear with me.

For maximum power output, you want the output voltage/current of the panel to be RIGHT ON THAT LINE. That means you MUST filter it. You adjust the buck converter to make that happen. You just dither the pulse width around that point of the curve...perturb and observe...

That's the concept. As a practical matter, you can consider the battery voltage to be pretty constant in the short term. You measure the charge current and optimize that with the pulse width. That automagically makes the panel voltage track at maximum. That works for all insolation levels above the 30V line. Panel current does not equal charge current. The peak charge current can be several times the panel output current for discharged battery and lotsa sun. That 100A FET may have to be a 400A FET capable of higher voltage.

By the time you're done with that, you will have learned that you do need an inductor and a capacitor on each end of it...well there's a diode on the bottom end.

If you plot insolation over the course of a year at the location, you'll also realize how little time the solar voltage stays over 30V in the winter. And how much more battery you need and how much bigger the solar panels need to be. And start thinking how to redesign the switcher to deliver some charge below 30V of solar output.

And you won't have spent a dime yet. And I haven't mentioned pulse charging at all. You can tweak that anywhere you want by varying the size of the bottom cap.

++++++++++++++++++++++++++++++++++++++++ I spent most of my career as project manager for test systems designed to be used by inexperienced users. I spent a lot of effort to reign in the excessive cleverness of the engineers where it added no value to the end user but made the system more difficult to use.

You're building a system to be used by someone else. It's unlikely that you could spend enough time to experience all the diversity that nature has to offer.

You do not want to build a system that causes the other guy grief. Or sets him on fire. Or lets his water system freeze.

I stand my my assessment that you can buy a better charge controller than you can build and for less money than you're gonna spend building it. Time is money. Get a job at minimum wage and buy him a controller. You'll still be money ahead.

I've done what you're doing many times. It rarely ended up cheaper.

Are we having fun yet?

dea. I am not going to build the charging system for the main system, there is too much out there that is too far beyond me. I am not learning to do s oftware and USB interfaces and all that shit. So that part of it is settled .

are a bit more efficient obviously, the wire gauges are half what they woul d be at 12, and going to higher voltages really gets into diminishing retur ns. It might not even be Tesla batteries, there are alternatives. Plus he a lready ordered the PV panels and is next going to deal with the mounting an d the tilting mechanism, which is not my job.

lator for that and have recommended that he get a regular lead acid battery for that, preferably deep cycle.

ulator to put out something like 14.8 volts, can I just dump that into the battery with no filtering ? AND, would it be advantageous to do so ?

ing puts out an AC current to the battery and that somehow makes it better. They claimed it knocked the sulfides off the plates or whatever.

It was probably a battery desulphater.

Sulphides don't show up in lead-acid batteries. Sulphides are chemical comp ounds containing sulphur atoms. Sulfides contain negatively charged SO3 gro ups, and sulphates contain negatively charged SO4 groups. You can oxidise s ulphur in sulphides to get sulfites and sulphates, but it does soak up oxyg en.

--
Bill Sloman, Sydney

e good..."

example is not filtered in any way and it is pretty much pulsed, though si ne type waves, at anywhere from like 2KHz to who knows. I was kinda thinkin g that a lower frequency would be better, but I am not sure of that. I must also admit ignorance on the subject but it looks like I won't be ignorant for long.

cold weather it will apply a higher charging voltage, once it all warms up it tapers off some. The reference voltage is not the output, it is off a s eparate set of tops of a three phase full wave bridge. so it is also partly current and partly voltage regulated. I thin it would maybe be a good idea to charge like that, since it has been working for the last forty years.

er battery. "

at. The balancer, as efficient as it may be it actually just partly shortin g out the top battery. I think with the batteries in parallel we would get more capacity in the end. The ONE regulator would be doing the charging, th e batteries, especially more than one would do most of the filtering. I dun no, it IS an option but I am not sure it is right for this project.

lfides, so they can be formed into chemically useful lead sulphate. "

ak current of the chopper(s). Actually just one 100 amp MOSFET should do it , no ?

That came from Robert Baer, who is a Baer of very little brain. Don't rely on it.

--
Bill Sloman, Sydney

See, what that should have been is "Wrong, check it out, [and whatever] can't you do that ?

T^T

ely on it."

an't you do that ?

Without significant chemistry knowledge, your post is near gibberish. Not 1

00% on me, I know A LITTLE BIT. I could very quickly sim up what I know abo ut chemistry.

I know about atoms, take or give electrons you get ions, give or take neutr ons to get isotopes, give or take protons and you got a different substance . Got ionic and covalent bonds and I ain't no expert on that either. But I don't claim to be. I know a little about ph and what makes ph, some things about properties, reacting with light or similar EM. I know hwy blue LEDs a re more expensive, but not EXACTLY why they have a higher junction drop.

If I forgot to mention a few things listing them would not take more text t han ^ that up there. Oh, I read somewhere how to make LSD25 but have never tried it and have no intention of doing it. More useless knowledge.

So you partly explained about the difference between a sulphate, ide, ite w hatever. I guess it could be considered interesting. The question however w as if AC is good for the battery.

Thusfar the general consensus seems to be yes. what frequency ? Well what f requency works ? A car alternator. It will be pulsing at maybe 3K up to who knows. Might be interesting to put a freq counter on one. Maybe I will.

The other thing is the charging parameters. I am recommending two new and s ame deep cycle marine batteries. I will not f*ck with charging the main bat teries, but the 12 volt subsystem I will. It will be a combination regulato r and charger. Since the battery likes pulses I will give it pulses. I'll f igure out the feedback loop somehow. This approach should save time, money, space and maybe a little bit of those spunky electrons, which shall be at issue.

On Wednesday, February 6, 2019 at 2:01:03 PM UTC-5, snipped-for-privacy@gmail.com wrote :

100% on me, I know A LITTLE BIT. I could very quickly sim up what I know a bout chemistry.

He didn't make it any easier to understand by using multiple spellings and poor wording. It was almost as if he didn't want anyone to understand what he was saying.

trons to get isotopes, give or take protons and you got a different substan ce. Got ionic and covalent bonds and I ain't no expert on that either. But I don't claim to be. I know a little about ph and what makes ph, some thing s about properties, reacting with light or similar EM. I know hwy blue LEDs are more expensive, but not EXACTLY why they have a higher junction drop.

than ^ that up there. Oh, I read somewhere how to make LSD25 but have neve r tried it and have no intention of doing it. More useless knowledge.

whatever. I guess it could be considered interesting. The question however was if AC is good for the battery.

Yes, well, if you are trying to sound smart it's always good to change the topic to one you are pretty sure no one else in the conversation knows.

frequency works ? A car alternator. It will be pulsing at maybe 3K up to w ho knows. Might be interesting to put a freq counter on one. Maybe I will.

I don't think the frequency is so important as long as it isn't very high. Remember, this is about atoms moving about in a liquid, so that takes time . I would say 1 kHz is the high end for this and I would not say 60 Hz it too low, but of course this is a gut feel and not based on anything I've re ad.

same deep cycle marine batteries. I will not f*ck with charging the main b atteries, but the 12 volt subsystem I will. It will be a combination regula tor and charger. Since the battery likes pulses I will give it pulses. I'll figure out the feedback loop somehow. This approach should save time, mone y, space and maybe a little bit of those spunky electrons, which shall be a t issue.

It's been a while since I read this thread. Why are you designing any of t his rather than using off the shelf units?

Rick C.

-- Tesla referral code -

d poor wording."

It could have been worse but I think if I find a wiki on it, it will be bet ter.

ng. "

Well it's hard to shoot someone 10,000 miles away. I'm pretty good but not that good.

too low..."

Well I guess I'll take that. A car alternator is much higher but nobody eve r claimed it keeps the sulphwhatevers off the plates.

"

We are doing that on the main 24 volt system. I am handling the 12 volt sub system. I have some ideas on exactly how I want the charger/regulator to be have.

Also it is work. I could search the internet and tell him what to buy and g ain like a 12 pack out of it. I'd rather handle it, lead acid will not be a big problem.

Another thing is that what I've done so far, and no there is not an off the shelf solution, I don't know what to charge for it. It is not all that tec hnical, just some PWM running some power MOSFETs, but what do you all charg e for that say, per hour ? I also have to build it and I don't really know what to charge for that.

Anyway, there will probably be a second alternator on it, isolated from gro und and in series with the original. The original can charge the 12 volt sy stem and the stacked one can charge the 24 volt system. And it will be sepa rate except for when the engine is running. I'll either come of the IGN lin e in the vehicle or run a relay off it for that. Being an alternator, the 2

4 volt system is automatically isolated except when the engine is running, it cannot discharge the batteries. Also, if he happens to run the vehicle b attery too low he'll have the option of actually jump starting it off the 1 2 volt system with the flip of a switch. We don't really anticipate that bu t better to have it and not need it.

So I don't know, I think it is 35 components, simple PWM, four independent channels. Outputs to a string of LEDs and can sink (they are common anode) around 20 amps per channel. Three dual OP AMPs, four power MOSFETs and a bu nch of penny ante shit. There have been four revisions. One his order, the others were overlooks on my part.

I got maybe ten hours into it but I am sure a real pro could do it in half the time.

What is fair ?

On Friday, February 8, 2019 at 4:43:31 AM UTC+11, snipped-for-privacy@gmail.com w rote:

te:

ot 100% on me, I know A LITTLE BIT. I could very quickly sim up what I know about chemistry.

d poor wording. It was almost as if he didn't want anyone to understand wh at he was saying.

I spelt sulphur as sulfur once in that short post. That probably counts as typo - it's conflict between the English spelling I grew up with an Noah We bster's corruption that Americans use (and I get to see quite frequently).

If you think the wording was poor, demonstrate how you would have done it b etter.

te whatever. I guess it could be considered interesting. The question howev er was if AC is good for the battery.

If somebody tells you that there are are sulphides in a battery, you can wo rk out that they don't know what they are talking about, which detracts fr om the credibility of their other claims.

e topic to one you are pretty sure no one else in the conversation knows.

The distinction between sulphides, sulphites and sulphates is very elementa ry chemistry. This is a largely university educated group, and I'd expect m ost people who post here would know the difference.

hat frequency works ? A car alternator. It will be pulsing at maybe 3K up t o who knows. Might be interesting to put a freq counter on one. Maybe I wil l.

. Remember, this is about atoms moving about in a liquid, so that takes ti me. I would say 1 kHz is the high end for this and I would not say 60 Hz i t too low, but of course this is a gut feel and not based on anything I've read.

I did a conductivity-measuring circuit once that generated a frequency outp ut - about 2.4kHz for tap water (300 microSiemens) to about 50kHz for 2% Na oH at 85C (300 milliSiemens). That signal went through the water.

The conductivity of water isn't about atoms moving through the water, but a bout ions. It's frequency dependence is captured by

which tends to give a 45 degree phase shift over a large frequency range.

What happens at the positive and negative plates of a lead acid battery dur ing charge and discharge is even more complicated, and someboyd blithering about "atoms" clearly hasn't got much insight into it.

this rather than using off the shelf units?

Probably because he thinks he can. Building stuff always looks cheaper than buying it, and until you figure in the cost of getting it to work.

I spent six years in the Nijmegen University science faculty workshop, and a lot of the job was persuading academics to go out and buy what they neede d, rather than wasting out time reinventing the wheel for them.

--
Bill Sloman, Sydney