3 Battery Generating System

[Aaron]

radio books

That is definitely the drawing that got me started down this path. But just to be a bit more historically accurate, John was talking about very SMALL batteries here. Probably around 1.5 volt, and a TINY light. And this method of recharging them was used way before John’s time by radio operators. I found documentation of this in some old radio books when I began researching this after several years to see why nobody had picked up on it. Turns out it was fairly common among a select group of folks.

I saw you mention that before - can you post the exact references - book titles, pages, etc. in the old radio books?

[bistander]

EverStart U1 Battery

I have been running a 3 Battery System with the following setup using 6 batteries, ...



Bob

Hi Bob,

I noticed you are using the EverStart brand U1, 230 CCA FLA batteries. Did you verify these to specifications or other test for capacity when you first got them? I ask because I have noticed something about one I just tested. I'll outline that below. First, a photo of my battery, and the Black & Decker (B&D) charger which I used.



I am using a West Mountain Radio CBA III tester and laptop to log constant current discharge and plot against Ampere-hours. Here is a family of curves at various C-rates. About 7.5A is the limit of the unit. The C/20 was interrupted due to laptop timeout. More on that later.



Next is a discharge comparison of the first run on this battery at 7.0A and cut-off set to 9.0V vs a similar run at 7.2A (C/2.5) with cut-off set to 10.5V done 4 days later. Notice a 12.7% increase in charge (Ah) on the later test. Also the the higher voltage for the later test indicates a much lower internal resistance and likely near 20% more energy from the battery under the same conditions and charged the same.



On the above curve, red trace for the 7.0A, notice the line goes horizontal near the end. This prompted me to further investigate when running the C/20 curve by setting a low cut-off. As I mentioned earlier, the length of the 20 hour discharge caused several computer disruptions so I simply started up again renaming part1, part2, etc, without recharging in between the parts. By doing this, the charge (Ah) from the individual parts are additive. Total Ah is 17.57Ah for the 20 hour rate. Although I was unable to find a specification on the EverStart U1, 230CCA battery, similar products appeared to be rated around 18Ah for 20 hours.* {see edit}



These "knees" on the discharge curves indicate a single cell (of the 6-cell battery) giving up. So this battery has one cell good for 12.02Ah, one cell good for ~15.36Ah and 4 cells good for 17.57Ah or more.

Just for kicks, I used my new instrument to record a partial recharge of this battery after the last test and calculated the Ah and Wh and plotted it. Takes a bit of time to do, but I think will yield some accurate energy data for both charge and discharge. Attached.



Regards,

bi

{edit of 13Feb2019} With further literature search, group U1 size lead-acid batteries are rated 32 to 35 Ah.

[altrez]

altrez,

That is definitely the drawing that got me started down this path. But just to be a bit more historically accurate, John was talking about very SMALL batteries here. Probably around 1.5 volt, and a TINY light. And this method of recharging them was used way before John’s time by radio operators. I found documentation of this in some old radio books when I began researching this after several years to see why nobody had picked up on it. Turns out it was fairly common among a select group of folks.

Try it as originally intended and then try it with your batteries and you will see dramatic difference in results. It won’t be nearly as efficient with the larger batteries. I realize that goes against what I said in my last post, but that’s what happens on the bench and I will always take what I see on the bench over anyone’s opinion or theory.

Hi Dave,

I agree with you again on everything you said lol. I have SEEN this work on my bench. I have done this lots of diffrent ways and have posted as much as I could over the last 10 years. I even posted in the old closed thread. The issue is however I did not log any of it working to share. So my goal for part one is to have a bunch of data to show what I know works and to share that so that others may also do the same and share their results!

I started with the small D battery's and a low voltage lamp and it ran far longer then I could believe. I then went up to the 7AH battery's and again saw some crazy cool results, I have even used caps and got it to work. The true setup should be in my opinion around 30 Trojan battery's but that is crazy expensive.

If you run across the article's again about others using the setup can you please share I would love to read them.

Thank you for all the help!

-Altrez

[axxelxavier]

I have been running a 3 Battery System with the following setup using 6 batteries, but it can be done with 3 batteries also. I wanted to go to 24 and 48 volts with a 24v potential difference, so I'm using 3 pairs of batteries. The middle battery (or batteries) are always part of the Primary...they never become used as the Battery 3. So I am only switching between the other two.
Also, I am adding solar to the middle batteries and this makes some very interesting advantages when there is good sun. Because the solar pushes these batteries high and they are in series with the other Primary batteries, The Primaries and the potential difference between the positives remain very high for a long time. It also allows for Battery 3 to be charged to a higher level before the system has to be switched. And because there is extra energy from the solar, all the batteries can gain as the system cycles.
I added a DPDT switch and by throwing that one switch I swap batteries AND reverse the leads of the load. This is because the middle batteries can have their positive as the high voltage positive (+) all the time and the other batteries provide the low voltage positive (-). This means that with one switch the low voltage positive changes. And the load is always attached to the middle Primary's high voltage positive (+), so only the low voltage side (-) needs to be changed. When it comes time to run the energy back the other way, you just throw one switch...and it's done.
Notes: The big orange switches are set and not changes in this setup. I use them to switch each pair of batteries between 12v and 24v. With this current setup they stay in 24v arrangement all the time. Also, if you notice that there are three thick red wires attached to the black switch. They are for switching the batteries and there are black wires for the load switching, but they are hard to follow. BTW, the load lead switches to the opposite side from the Secondary that is being switched to.
It's been a while since I've posted, but I've been researching, experimenting and building all the time...every day. Enjoy.
Bob

Excellent idea, to replenish juice in battery 2 using solar panel!
But why switching the load polarity, when you can use battery 1 to be the one common from your primaries, to be charged by your solar panel, and choose instead, for your second setup, to use battery 1 AND 3 in series?
In following post, setup 1 and setup 3 share same load polarity:http://www.energeticforum.com/315444-post4439.html, so it would be easier for you, don't you think?
Best regards,
Teodor

[Turion]

“John’s” 3 Battery swap

altrez,

That is definitely the drawing that got me started down this path. But just to be a bit more historically accurate, John was talking about very SMALL batteries here. Probably around 1.5 volt, and a TINY light. And this method of recharging them was used way before John’s time by radio operators. I found documentation of this in some old radio books when I began researching this after several years to see why nobody had picked up on it. Turns out it was fairly common among a select group of folks.

Try it as originally intended and then try it with your batteries and you will see dramatic difference in results. It won’t be nearly as efficient with the larger batteries. I realize that goes against what I said in my last post, but that’s what happens on the bench and I will always take what I see on the bench over anyone’s opinion or theory.

[altrez]

altrez,
I hate to discourage you, but as I have said hundreds of times over the last ten years, small batteries are not going to cut it if you expect to see anything.


I am trying to be as honest as I can. The difference between success and failure with this system is NOT huge, and you need every bit of help you can get. The conductance, internal resistance and impedance of a battery are linearly correlated to each other across a wide range of battery capacities, and are basically a measure of the same thing. The smaller the battery, the more "resistant" it is to charging, which basically means there are two separate and distinct "costs" to charging a battery. The first is the amount of energy you actually put into the battery. The second is what you pay to "be allowed" to put that energy into the battery in the first place. Think of it as a "tax" you pay to charge a battery. The bigger the battery, the smaller the tax. The smaller the battery, the larger the tax.

So when you are trying to recycle energy or conserve energy with a very small prototype system like you are building, that tax is going to KILL your results.

Minimums for success:
___________________
Large systems with large deep cycle batteries.
Pulsed charging
Voltage 2.5 volts higher than the standing voltage of the battery.

I asked Bob French to post and show how he was currently using a small solar panel to take advantage of the 3 Battery system, because I know how much testing of this system Bob has done, and he and I talk all the time.

ANOTHER way to gain an advantage using the 3 battery type setup with solar is to run your inverter between the output of the solar panel's charge controller and the batteries you are trying to charge. Put ALL the batteries from your whole system in parallel which means you maintain the potential difference for the longest time possible. Then when all the batteries are charged, run the inverter directly off them. You have used the energy TWICE. You have basically doubled the time your system can run on the batteries you have. If the output voltage of your particular charge controller is not high enough to allow you to do that, well that's what a boost module is for.

Hello Dave,

I am in total agreement with you about the larger battery's. The effect is impossible to miss on the larger battery's. I have noticed this on small 1.5v Dcells as well.

I have seen this work with the 7AH battery's and while I agree its not going to blow your mind with the results, it works and I am going to log it this time.

This is for the first part of my PDF the simple 3 battery swap that John posted so long ago. I will get on to adding boost modules and better battery's later For now this is all I am working on:



As always thank you for the help,



-Altrez

[Turion]

System

altrez,
I hate to discourage you, but as I have said hundreds of times over the last ten years, small batteries are not going to cut it if you expect to see anything.


I am trying to be as honest as I can. The difference between success and failure with this system is NOT huge, and you need every bit of help you can get. The conductance, internal resistance and impedance of a battery are linearly correlated to each other across a wide range of battery capacities, and are basically a measure of the same thing. The smaller the battery, the more "resistant" it is to charging, which basically means there are two separate and distinct "costs" to charging a battery. The first is the amount of energy you actually put into the battery. The second is what you pay to "be allowed" to put that energy into the battery in the first place. Think of it as a "tax" you pay to charge a battery. The bigger the battery, the smaller the tax. The smaller the battery, the larger the tax.

So when you are trying to recycle energy or conserve energy with a very small prototype system like you are building, that tax is going to KILL your results.

Minimums for success:
___________________
Large systems with large deep cycle batteries.
Pulsed charging
Voltage 2.5 volts higher than the standing voltage of the battery.

I asked Bob French to post and show how he was currently using a small solar panel to take advantage of the 3 Battery system, because I know how much testing of this system Bob has done, and he and I talk all the time.

ANOTHER way to gain an advantage using the 3 battery type setup with solar is to run your inverter between the output of the solar panel's charge controller and the batteries you are trying to charge. Put ALL the batteries from your whole system in parallel which means you maintain the potential difference for the longest time possible. Then when all the batteries are charged, run the inverter directly off them. You have used the energy TWICE. You have basically doubled the time your system can run on the batteries you have. If the output voltage of your particular charge controller is not high enough to allow you to do that, well that's what a boost module is for.

[altrez]

altrez,
How you start depends on what you are trying to do. With two fully charged batteries and a third battery fully charged your potential difference is going to remain constant for longer because it is harder to charge a fully charged battery. But you are also throwing power away trying to overcome the resistance in the fully charged battery and charge it. With a dead third battery the potential difference is high to begin with but that drops as the primaries lose charge and battery 3 charges. Both will teach you things, but until you add s boost module and a pulsing circuit of some kind, either mechanical like Matt’s motor or digital like an Arduino running a 555 timer, you will never see the real potential of this system.

Hello Dave,

Thank you for the input. I do agree you need to add the boost module and Matt's motor / pulse circuit. My goal for this test is to start with the most basic of setups. And when I say basic I am talking 3 battery's and a controlled load.

I am working on a PDF that has everything from the start of this over 10 years ago to the current builds. I felt like the best place to start this documentation was with the simple 3 battery swap and go from there.

I know it works however I have never fully documented it in great detail. So I have ordered another data logger and another DC load tester plus four new 7AH battery's.

I will post all of my tests and a link on dropbox to the pdf.



-Altrez

[Turion]

3 Battery System

altrez,
How you start depends on what you are trying to do. With two fully charged batteries and a third battery fully charged your potential difference is going to remain constant for longer because it is harder to charge a fully charged battery. But you are also throwing power away trying to overcome the resistance in the fully charged battery and charge it. With a dead third battery the potential difference is high to begin with but that drops as the primaries lose charge and battery 3 charges. Both will teach you things, but until you add a boost module to keep the voltage higher than the battery you are trying to charge and a pulsing circuit of some kind, either mechanical like Matt’s motor or digital like an Arduino running a 555 timer, you will never see the real potential of this system. The battery being charged MUST be hit with pulses of the CORRECT frequency at at least 2.5 volts over the battery standing voltage. I recommend about 16.5 volts which is a couple volts over what you want the 3rd battery to charge to.

I used to run FIVE six volt batteries on top and two on the bottom. Then I didn’t need a boost module and all I needed was a pulse motor and rotating batteries properly.

[altrez]

Question for the group,

When starting your tests with the 3BS do you start with 3 full battery's or with 2 full battery's and the 3rd being at a lower voltage?

I have been starting with my 3rd battery at 11.5 and the other two at 12.6-8.

What are you guys / gals thoughts on the best way to start out?

-Altrez

[altrez]

Would you mind providing a link to that item, wouldn’t mind looking into that

Hello Sawt2,

Here is the link:

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

I am really enjoying it so far. I have also used it today to test one of my USB power packs and it worked great.



-Altrez

[Sawt2]

Hello All,

I picked up on Amazon a small adjustable DC load so I could test my battery's consistently. It works pretty good so far and I am testing now with a 7ah battery at the c20 ratting.





I am going to compare the time on a stand alone battery and then on the 3bs with this as the load. Seems like a good start.

-Altrez

Edit: Not sure what I was thinking this morning but that was a 5ah battery. I have adjusted the load to 0.250

Would you mind providing a link to that item, wouldn’t mind looking into that

[altrez]

Hello All,

I picked up on Amazon a small adjustable DC load so I could test my battery's consistently. It works pretty good so far and I am testing now with a 7ah battery at the c20 ratting.





I am going to compare the time on a stand alone battery and then on the 3bs with this as the load. Seems like a good start.

-Altrez

Edit: Not sure what I was thinking this morning but that was a 5ah battery. I have adjusted the load to 0.250

[BobFrench]

Simple switching...very cool. Add a little solar.

I have been running a 3 Battery System with the following setup using 6 batteries, but it can be done with 3 batteries also. I wanted to go to 24 and 48 volts with a 24v potential difference, so I'm using 3 pairs of batteries. The middle battery (or batteries) are always part of the Primary...they never become used as the Battery 3. So I am only switching between the other two.
Also, I am adding solar to the middle batteries and this makes some very interesting advantages when there is good sun. Because the solar pushes these batteries high and they are in series with the other Primary batteries, The Primaries and the potential difference between the positives remain very high for a long time. It also allows for Battery 3 to be charged to a higher level before the system has to be switched. And because there is extra energy from the solar, all the batteries can gain as the system cycles.
I added a DPDT switch and by throwing that one switch I swap batteries AND reverse the leads of the load. This is because the middle batteries can have their positive as the high voltage positive (+) all the time and the other batteries provide the low voltage positive (-). This means that with one switch the low voltage positive changes. And the load is always attached to the middle Primary's high voltage positive (+), so only the low voltage side (-) needs to be changed. When it comes time to run the energy back the other way, you just throw one switch...and it's done.
Notes: The big orange switches are set and not changes in this setup. I use them to switch each pair of batteries between 12v and 24v. With this current setup they stay in 24v arrangement all the time. Also, if you notice that there are three thick red wires attached to the black switch. They are for switching the batteries and there are black wires for the load switching, but they are hard to follow. BTW, the load lead switches to the opposite side from the Secondary that is being switched to.
It's been a while since I've posted, but I've been researching, experimenting and building all the time...every day. Enjoy.

Bob

[Iamnuts]

My belief.

This is the sort of thing my own experience has shown me.


Answering to the question "Is there data available to quantify a loss in lead-acid battery quality from low-voltage events?" here are two good sources:

"Battery life is directly related to how deep the battery is cycled each time. If a battery is discharged to 50% every day, it will last about twice as long as if it is cycled to 80% DOD[1]. If cycled only 10% DOD, it will last about 5 times as long as one cycled to 50%. Obviously, there are some practical limitations on this - you don't usually want to have a 5 ton pile of batteries sitting there just to reduce the DOD. The most practical number to use is 50% DOD on a regular basis." -- https://www.solar-electric.com/deep-...ttery-faq.html

"typical life of starter and deep-cycle batteries when deep cycled:

Depth of Discharge Starter Battery Deep-cycle Battery
------------------------------------------------------------
100% 12–15 cycles 150–200 cycles
50% 100–120 cycles 400–500 cycles
30% 130–150 cycles 1,000 and more cycles
" -- Lead-based Batteries Information ? Battery University