End amps vs Float current

[Barry Fields]

The company Multitel has an extensive explanation of FLOAT CURRENT MONITORING.

https://www.multitel.com/float-current-monitoring-a-complete-overview/

Below are two quotes I feel are worth highlighting:

Battery chemistry, battery design, quality of material, manufacturing process and battery capacity (AH) will ultimately influence the rate of self discharge of any lead acid batteries. Thus, the typical float current value will differ from one model to another.

Since the early 2000, float current measurements have been accepted for determining SoC (State of Charge) of VLA and VRLA batteries (see IEEE-450). As hygrometers are not easy to use and testing is time consuming, SG measurements can be replaced by float current measurements. Float current has an advantage in that it provides an indicator of the entire battery string, while specific gravity is measured on a cell-by-cell basis.

Should MidNite decide to pursue the CHARGING REGIMEN I have proposed, Multitel may be a valuable engineering resource.

I am surprised that I have not yet received ANY negative feedback on my proposal. I cannot possibly be that correct.

PS - Thanks for the promotion to Jr Member. At 74 it has been a while since I have been called Jr. Maybe ROJM (Really Old Jr Member)

Hi Barry,

It is just me,  but, any "Authority", regarding FLA batteries,  that calls an Electrolyte Density-measuring device, a "Hygrometer" (which generally measures the proportion of water, present in, gas/es,    like those in air, instantly loses 98.998% of any credibility, about all the other "info", provided.

IMO,  there are many, many ...  many variables when charging/discharging,  and measuring/inferring SOC, and SOH of batteries.  None of the methods used need to be perfect,  just, perfectly adequate.

It is often proposed, that, when possible,  a person needing a battery system,  buy a set of batteries, ideally,  FLAs, true deep-cycle, like GCs,  and learn how to use them,  and use accepted measurements  --  a Hydrometer,  and Pilot Cells, for quick readings on the average, nominal SOC.

Monitor, carefully,  the amount of replenishment Distilled Water, for each battery  ...
Create a Log Book,  for that batt bank,  record charge settings, EQ duration, and voltage,  battery current, etc,  then sit back, and enjoy the fruits of the labor,  and wisdom that you have gained.
Over time,  the battery current reduction, during EQ can imply battery SOH,  and when further EQing will probably have diminishing effect.
IMO, again,  USE A BTS, with FLA batts,  AND, Temp Comp the EQ voltage  ...

AND, as always,  I am NO battery expert,  am still practicing, though.

IMO, FWIW ...  YMMV, and so on Vic

I try to ignore spelling and punctuation when I am reading for content and the ideas behind that content. Just me.

My last conversation with Rolls Battery was instructive. The support rep stated that NO solar company charges batteries properly except for Outback. My interpretation is that they may be the only ones doing it the "Rolls way".
The rep also stated that he had been doing this for 30 years. That translates to "we have always done it this way and there is no reason to entertain anything new" IMHO

I certainly hope that MidNite does not feel the same way. I understand that the perfect should not stand in the way better.

Yes, this is true !  Depending on the battery type, 30 mV may or may not be a problem.  For lead acid, no problem IMO.

Most of what I have read about balancers and East Penn is the goal is that more than 10mv per cell is an indicator of a problem. Lithium imbalances are a safety issue(smoke/fire). For lead acid batteries, it would be an alert to an imbalance. What to do to correct or prevent that imbalance is a separate discussion.  One needs to know that an issue exists before you try to address it.

QED

boB [/quote]

[boB]

The company Multitel has an extensive explanation of FLOAT CURRENT MONITORING.

https://www.multitel.com/float-current-monitoring-a-complete-overview/

Below are two quotes I feel are worth highlighting:

Battery chemistry, battery design, quality of material, manufacturing process and battery capacity (AH) will ultimately influence the rate of self discharge of any lead acid batteries. Thus, the typical float current value will differ from one model to another.

Since the early 2000, float current measurements have been accepted for determining SoC (State of Charge) of VLA and VRLA batteries (see IEEE-450). As hygrometers are not easy to use and testing is time consuming, SG measurements can be replaced by float current measurements. Float current has an advantage in that it provides an indicator of the entire battery string, while specific gravity is measured on a cell-by-cell basis.

Should MidNite decide to pursue the CHARGING REGIMEN I have proposed, Multitel may be a valuable engineering resource.

I am surprised that I have not yet received ANY negative feedback on my proposal. I cannot possibly be that correct.

PS - Thanks for the promotion to Jr Member. At 74 it has been a while since I have been called Jr. Maybe ROJM (Really Old Jr Member)

Hi Barry,

It is just me,  but, any "Authority", regarding FLA batteries,  that calls an Electrolyte Density-measuring device, a "Hygrometer" (which generally measures the proportion of water, present in, gas/es,    like those in air, instantly loses 98.998% of any credibility, about all the other "info", provided.

IMO,  there are many, many ...  many variables when charging/discharging,  and measuring/inferring SOC, and SOH of batteries.  None of the methods used need to be perfect,  just, perfectly adequate.

It is often proposed, that, when possible,  a person needing a battery system,  buy a set of batteries, ideally,  FLAs, true deep-cycle, like GCs,  and learn how to use them,  and use accepted measurements  --  a Hydrometer,  and Pilot Cells, for quick readings on the average, nominal SOC.

Monitor, carefully,  the amount of replenishment Distilled Water, for each battery  ...
Create a Log Book,  for that batt bank,  record charge settings, EQ duration, and voltage,  battery current, etc,  then sit back, and enjoy the fruits of the labor,  and wisdom that you have gained.
Over time,  the battery current reduction, during EQ can imply battery SOH,  and when further EQing will probably have diminishing effect.
IMO, again,  USE A BTS, with FLA batts,  AND, Temp Comp the EQ voltage  ...

AND, as always,  I am NO battery expert,  am still practicing, though.

IMO, FWIW ...  YMMV, and so on Vic

I try to ignore spelling and punctuation when I am reading for content and the ideas behind that content. Just me.

My last conversation with Rolls Battery was instructive. The support rep stated that NO solar company charges batteries properly except for Outback. My interpretation is that they may be the only ones doing it the "Rolls way".
The rep also stated that he had been doing this for 30 years. That translates to "we have always done it this way and there is no reason to entertain anything new" IMHO

I certainly hope that MidNite does not feel the same way. I understand that the perfect should not stand in the way better.

Yes, this is true !  Depending on the battery type, 30 mV may or may not be a problem.  For lead acid, no problem IMO.

Most of what I have read about balancers and East Penn is the goal is that more than 10mv per cell is an indicator of a problem.

 

Maybe that is because they sell battery balancers that can get the balance that close ?

Lithium imbalances are a safety issue(smoke/fire). For lead acid batteries, it would be an alert to an imbalance. What to do to correct or prevent that imbalance is a separate discussion.  One needs to know that an issue exists before you try to address it.

QED

 

I think that for Lithium, I would not want them to be off balance by much at all, even for string capacity sake, as well as for safety.

I wonder what Outback does that they like so much ?  I am guessing that it has to do with Outback's float cut-off time and re-float voltage settings to bring it back into float.  The idea is that floating all the time can reduce the life of a LA battery.
Was it Steve Higgins that you talked to ?

Checking out the Multitel thing.
boB

[ClassicCrazy]

Barry ,
Look up Lead Crystal type batteries. They are like gel but the electrolyte is never supposed to let the plates sulfate even if they go way below voltage.
Not sure if it is all hype or real tech.
I happen to have some though I bought them because that is what my battery dealer had at a nice price. He said he had heard good things about them being used in Africa.
Here is one link to a type - but there are others, maybe they are all made in the same plant in China and have different branding ?
https://greencrystalbatteries.com/pages/about-lead-crystal-batteries
https://soneil.com/products/battery/
Larry

[Barry Fields]

I wonder what Outback does that they like so much ?  I am guessing that it has to do with Outback's float cut-off time and re-float voltage settings to bring it back into float.  The idea is that floating all the time can reduce the life of a LA battery.
Was it Steve Higgins that you talked to ?

Checking out the Multitel thing.
boB

Yes is was Steve Higgins. I believe that Rolls wants end amps to last for 1 hour.
I do not approve because it could cause overcharging depending on the day's conditions.
I am trying to prevent both under and over charging for the sake of battery life.

I do not have the resources to effectively put a stamp of approval on my suggested process. I have the ability to physically monitor end amps and float current. I have adjusted absorb times and spent hours watching my system for transitions from absorb to float,  I have no way to force that transition in either direction.
EastPenn has quoted my battery's 100% SOC float current @ 450ma (2.1ma/AHC).
In looking at the charge efficiency curve, I can only guess that the 95%SOC value would be approximately 2-3 times the 100% value. I have achieved values for float current between 600-1200ma which would be in that 95-100% range.
If I had the resources, I would verify the projected 95%SOC value through actual test of a battery. (overcharge, float stabilized, read 100%, fixed 5% discharge, float stabilized, read 95%)

I truly believe that my process would be a better mouse trap.

Thanks for your support
Barry

[Barry Fields]

Barry ,
Look up Lead Crystal type batteries. They are like gel but the electrolyte is never supposed to let the plates sulfate even if they go way below voltage.
Not sure if it is all hype or real tech.
I happen to have some though I bought them because that is what my battery dealer had at a nice price. He said he had heard good things about them being used in Africa.
Here is one link to a type - but there are others, maybe they are all made in the same plant in China and have different branding ?
https://greencrystalbatteries.com/pages/about-lead-crystal-batteries
https://soneil.com/products/battery/
Larry

Do they seem to work for you? I did notice that the web sites did not offer much in the way of tech data. Most of the support info I found were either from the manufacturers or sellers.
Understand that I am a skeptic. I sometimes doubt what I think I know.
I would hesitate until there are many more charts and graphs on performance.
?? Why did your dealer have such a good price ??

Hope to meet or talk to ya someday,
Barry

[ClassicCrazy]

Barry ,
Look up Lead Crystal type batteries. They are like gel but the electrolyte is never supposed to let the plates sulfate even if they go way below voltage.
Not sure if it is all hype or real tech.
I happen to have some though I bought them because that is what my battery dealer had at a nice price. He said he had heard good things about them being used in Africa.
Here is one link to a type - but there are others, maybe they are all made in the same plant in China and have different branding ?
https://greencrystalbatteries.com/pages/about-lead-crystal-batteries
https://soneil.com/products/battery/
Larry

Do they seem to work for you? I did notice that the web sites did not offer much in the way of tech data. Most of the support info I found were either from the manufacturers or sellers.
Understand that I am a skeptic. I sometimes doubt what I think I know.
I would hesitate until there are many more charts and graphs on performance.
?? Why did your dealer have such a good price ??

Hope to meet or talk to ya someday,
Barry

I guess the dealer just happened to have what I needed in stock - the cost was around 4 thousand for 24v 540ah if I remember correctly. At the time I would have had to order the flooded forklift type ( the kind that came with studs so you can move each cell separately). It was nice to have the sealed batteries because you can move them around without having to worry about the juice in them spilling out. The other reason I got these is because they have very good low temperature performance and I had them in unheated place. One winter it was down to -40F and while they were not happy charging at that temp they got me through the extreme cold until it warmed up in a day or two. All in all they have performed okay for me -I tried to not take more than 20% out of them for better longevity. The nice thing is not having to mess around with taking SG readings and watering them. You are right - there is not a lot of technical or real experience with these though I haven't looked for awhile. I took the gamble getting them and it seems to have paid off in the long run.  I have basically moved on to 48v lithium , I still have them on a separate system which I mostly use for supplying DC loads ( via 12v converter).
Larry

[Barry Fields]

Before you read the attached, I need you to understand the following:

55 years ago on a day very much like today, I was studying Vacuum Tube design. Yes it was a time when we had TV repair men. You could take your # 27 vacuum tube to the hardware store and test it.

It was in that bygone era I was subjected to classes in FORTRAN and COBOL.

The attached is a proposed algorithm for "float current controlled charging". It is crude by today's standards but I hope it is illustrative. I have assumed some numbers that would have to be proven in the real world.

That being said, you are allowed to chuckle amongst yourselves, however I am sensitive to overt belly laughs.

Barry

[boB]

That being said, you are allowed to chuckle amongst yourselves, however I am sensitive to overt belly laughs.

Barry

ROFL !

No, not at all.  That is about right.  We use fail days for Auto-EQing the battery so that it wouldn't keep trying to go high voltage day after day (for too long) if not quite enough sun was available.

Waiting 15 minutes  for ending amps before going to Float is good too.  We wait something like 90 seconds but either one is probably fine.

boB

[Barry Fields]

ROFL !

Glad I was able to brighten up your day.

I chose 15 minutes because Rolls wanted 1 hour after end amps. 15 minutes would prevent too many loops back to absorb.
Again, real world testing beyond my skill set and resources.
Barry