my "unsolvable problem"

[HRTKD]

Are there only two wires connecting the batteries to the rest of the system? I was trying to follow the wires but it looks like there is a positive wire coming down from the ceiling between the two batteries and then a bigger wire on the right going out the wall.

It isn't pertinent to your voltage drop, but what gauge wires are used in this?

If it goes into float, there is a quick voltage drop. Does it continue to drop if you don't let the charger go back into float/bulk?

 

[olmz]

Are there only two wires connecting the batteries to the rest of the system? I was trying to follow the wires but it looks like there is a positive wire coming down from the ceiling between the two batteries and then a bigger wire on the right going out the wall.

It isn't pertinent to your voltage drop, but what gauge wires are used in this?

If it goes into float, there is a quick voltage drop. Does it continue to drop if you don't let the charger go back into float/bulk?

thank you.

first, the wires that go up to to the magnum 2812, exactly as this system is intended to do. I am sorry that that is not visible in the picture. I could rustle up a picture if it helps you, but what you will see are the other sides of the compartment with what is a 400 amp fuse (the size recommended and indeed, I need it in this system,) and then both red and black going to the magnum.

forgive me, but while I don't remember the gauge, the wires are bigger than they need to be....done to accomodate more batteries and a much larger system at some near term point. I bought them from batterycablesusa upon industry folks who suggested that they are a good supplier...and they have been.

the quick voltage drop...takes about 20 minutes before it is down to low 13s....happens whether it ends in float mode or "silent" mode, both of which are acceptable in this circumstance and the 2812s with current firmware offer both choices.

the charger goes right back into an absorb charge when that happens, unless I put the charger portion of the magnum on standby (which happens automatically if you go into "silent" mode...but again, no final setting stops the drop....

I almost would not care but:

1. this means that for the most part, the batteries are not fully charged and when I go into the next outage, especially with a large residential fridge and other higher current appliances, who knows how much power I will really have?

2. while I have been told that I cannot hurt the batteries unless charging voltages are too high (they are not), but I still don't like the idea of charging cycles taking place when they don't have to...even these good batteries are still essentially a non-renewable resource.

finally, the precipitous drop happens whether or not the solar panels and solar controller are on. for testing purposes I have had them off for quite some time now, and I don't recall how much having them on slows the drop down, but it did not make much difference. don't forget, I am on shore power all the time now, save when the power goes off or I have some other kind of emergency where I would have to leave with the trailer (may that never happen again).

again, thank you.

 

[olmz]

Was the bogart trimetric showing a full charge percentage wise? The bogart if configured properly and wired with good connections is probably your most accurate measuring device in your system. Much more than the magnum BMK if you are using one of those. I have magnum inverters and bogart trimetric on both of my systems. One for the house and one for the camper. The trimetric comes within a one or same percent of the BMS reading and the magnum is always farther out in comparison on both systems .

You are. Charging to 3.6/ cell and then floating at 3.4/ cell. Does the inverter swap from shore to battery when this happens? 3.4 with a long enough absorb will fully charge without going to 3.6 so anything above 3.4 would be a surface charge at least for most DIY packs and would quickly drop to resting voltage if you applied a load to it just the passive current of the magnum at 10 watts on battery saver search would knock of the surface charge pretty quick. Note I use DIY packs and have no experience with the Battle Birn batteries.

the bogart unit always registered a tenth of a volt less than the magnum panel. as mentioned, I also have a seelevel device which passively measures tank volumes......and it has a button to look at battery voltage....it is always the same as the magnum panel, except that when the panel "flickers" ( meaning the voltage reading, not the readout itself) from say, 13.6 to 13.5 (on its way down, that is what happens), the seelevel device does not flicker with it...but measures the next step down when it firmly happens.

i have had that device since day one....as well as the bogart unit, and both still seem normal.....provided that as mentioned, the bogart unit is disconnected until I fix this....reducing variables.....

the inverter does NOT swap to battery when any of this happens. if i just let the batteries go for say a week or two, eventually they will drop below 13 volts, of course, and at some point, as things get closer to 12 volts, the magnum will simply stop working all together as it needs to see 12 volts+ in order to even pass thru shore power. that has only happened once in this latest round, as I don't let it get to that level.

thanks for all..............................

 

[olmz]

Are there only two wires connecting the batteries to the rest of the system? I was trying to follow the wires but it looks like there is a positive wire coming down from the ceiling between the two batteries and then a bigger wire on the right going out the wall.

It isn't pertinent to your voltage drop, but what gauge wires are used in this?

If it goes into float, there is a quick voltage drop. Does it continue to drop if you don't let the charger go back into float/bulk?

sorry but did i properly answer your question about the voltage drop?

again, thanks.

 

[HRTKD]

sorry but did i properly answer your question about the voltage drop?

again, thanks.

Yes, you answered my question. I can tell that this problem is concerning you quite a bit. It would bother the heck out of me too. We'll figure it out. Be patient with the brain trust here. We can be a bit direct at times.

You've swapped in the other set of batteries, so I don't think that the problem lies with the batteries. However, to rule that out, you could charge the battery bank and then disconnect it from everything outside the battery bank. No connections at all. You've essentially done this already when you charged the batteries individually. But were you checking for voltage drop at that time?

I don't think the problem lies with your cables or the connections. When there is a poor connection, we see issues when the system is under load. You're seeing voltage drop when there should be no load.

When the Trimetric was in place, did it register a draw on the battery bank after charging was complete?

Thinking out loud, voltage drop happens under these conditions:
1. A load
2. A failed or failing battery
3. A battery that has been charged and allowed to rest

Those are the scenarios that I can come up with right now. I'm brainstorming, so bear with me.

A LiFePO4 battery has a very flat voltage during discharge and charge between the knees. For you to see such a large voltage drop after a charge would require a heavy load. Some voltage drop is natural, but if a load is on then the voltage drop may be more pronounced.

If you have a clamp on ammeter, put it on one of the cables between the battery and the inverter/charger while the battery is charging. Orient the ammeter so that the meter is reading positive amps. When charging is done, read the meter again. If the batteries are under a load, you'll see a negative number. Be sure your ammeter is set for DC amps, not AC amps. While charging, verify that the meter's amps agree with what the Magnum is reporting.

 

[olmz]

Yes, you answered my question. I can tell that this problem is concerning you quite a bit. It would bother the heck out of me too. We'll figure it out. Be patient with the brain trust here. We can be a bit direct at times.

You've swapped in the other set of batteries, so I don't think that the problem lies with the batteries. However, to rule that out, you could charge the battery bank and then disconnect it from everything outside the battery bank. No connections at all. You've essentially done this already when you charged the batteries individually. But were you checking for voltage drop at that time?

I don't think the problem lies with your cables or the connections. When there is a poor connection, we see issues when the system is under load. You're seeing voltage drop when there should be no load.

When the Trimetric was in place, did it register a draw on the battery bank after charging was complete?

Thinking out loud, voltage drop happens under these conditions:
1. A load
2. A failed or failing battery
3. A battery that has been charged and allowed to rest

Those are the scenarios that I can come up with right now. I'm brainstorming, so bear with me.

A LiFePO4 battery has a very flat voltage during discharge and charge between the knees. For you to see such a large voltage drop after a charge would require a heavy load. Some voltage drop is natural, but if a load is on then the voltage drop may be more pronounced.

If you have a clamp on ammeter, put it on one of the cables between the battery and the inverter/charger while the battery is charging. Orient the ammeter so that the meter is reading positive amps. When charging is done, read the meter again. If the batteries are under a load, you'll see a negative number. Be sure your ammeter is set for DC amps, not AC amps. While charging, verify that the meter's amps agree with what the Magnum is reporting.

you are too kind. thank you. yes, this problem does bother me very much. I don't want to put anyone through chapter and verse on my personal hells, but I am fighting a lot of battles due to age, infirmity and my responsibilities to others. I am not complaining or a complainer, and I am not a victim...but my plate is always full at a time when I wish I could slow down and were more able to accomodate the craziness around me....but it seems to be my karma that the oddest problems, et. al., are going to land on my doorstep, even as I try to outthink the world and stay one step ahead.

Anyway, I really appreciate this help.

I *think* the Trmetric always registered in lockstep (albeit one tenth of a volt less, per my email to another poster here) with what I was seeing elsewhere. I know not being sure, is not good enough, but the last time the trimetric was hooked up it began to...first time ever...suffer from an odd "pulsation" which even effected a few of the 12 volt lights inside the trailer.

after my "what else is going to happen" reaction, I realized by process, that it was not working right, and took the fuse out of line to shut it down.

I would like to suggest this is an important symptom, but both before it began to go odd, so to say, and afterwards, all the other symptoms existed and remain...and taking it off line stopped all that funny business with the lights...so my belief is that this may well have been a result of messing with the system to install the new batteries...maybe the fuse holder after sitting there for over 7 years.....but that it is not a central issue since disconnecting it did not change the main problem.

So in truth, I am not positive what it said at various times, as indeed, I never really paid a lot of attention to it, given that for 7 years, this system was working well.

I read your whole note and to the extent I am learning fast about all this.................also my tech is super and a good and honest man...and I am in the relative middle of nowhere, so such help is not readily avialable after him........is also now unwell with some serious, albeit curable issues...but I have not had him available to me in the interim and that has been a problem too as I have medical issues which make easy things not so easy for me, depending (among them five hand surgeries and that is not the worst of it so you can get the picture)...........................and as a person who is not unfamiliar with things "electric' although the trailer eco system has not been, from a learning perspective, my priority until recently....................to wit, I am an amateur radio operator for many years........everything you say makes completel sense to me.

that said, as mentioned previously in case it may have been lost in my volume of words, two sets of four BB batteries each have been tried here (I have 8 batteries in total) and all eight batteries...two sets of four....show the same issues when in the system....eliminating in my mind, the possibility of one BMS failure somewhere, etc.

IOW, fwiw, I agree with you on your analysis, but do not have a clue what that might be. i don't have a clamp on meter (my tech does...<sigh>...but fwiw, I do have a good fluke VOM. if the tech is not able to come here this week....I will ask him to lend me his...as I looked into this and a good one (fluke) is extremely expensive.....4 figures. that said, if you know of one which is acceptable in quality but not a couple of thousand...although at this point, I am prepared to do just about anything.....and can justify it with "who knows what the future holds", .....................I will do what I have to...so pse give me your opinion if you don't mind.

I have gone thru my mind, every appliance that I have in this box, and I just am seeing nothing which appears to indicate some problem which would be causing a constant load. indeed, as I have said, I have shut down the solar part of my life, simply to eliminate all I can, anything which might be causing an issue...and as you know from my total lack of brevity, here, I have tried two different 2812s, as well as two different magnum panels as well.

so I am on hold for a few more days in the meantime, waiting on my poor tech with his problems.......but that said, it has also been suggested that after hooking up the busbars...again, my sense, too, is that that won't change things but by process of elimination..............that i also try the CC/CV settings on the magnum.....so as I work through this list, I have that option as well.

as to your comment about bearing with you, please....don't think twice about that. I am literally grateful for the help here and the good news is that at the moment shore power is working, I am not in an emergency where I have to leave and take the trailer with me (my life circumstance, even at this age....in my 70s....is such that that remains a possiblity, although I hope I am done traveling......so for the moment, this is a nasty and elegant problem, but I am suriviving it, at risk of the appearance of melodrama in the way I put this.

so kindly take your time so you don't have my full weight on you ...and I am thankful in advance for all your thoughts...as well of all others.

this is a fine place to vet such things and every poster's responses have been fully welcome on this end...direct or not as the case may have been or be.

I will stand by for your comments about a clamp ammeter and then take steps to do something more.

thanks again.

 

[olmz]

you are too kind. thank you. yes, this problem does bother me very much. I don't want to put anyone through chapter and verse on my personal hells, but I am fighting a lot of battles due to age, infirmity and my responsibilities to others. I am not complaining or a complainer, and I am not a victim...but my plate is always full at a time when I wish I could slow down and were more able to accomodate the craziness around me....but it seems to be my karma that the oddest problems, et. al., are going to land on my doorstep, even as I try to outthink the world and stay one step ahead.

Anyway, I really appreciate this help.

I *think* the Trmetric always registered in lockstep (albeit one tenth of a volt less, per my email to another poster here) with what I was seeing elsewhere. I know not being sure, is not good enough, but the last time the trimetric was hooked up it began to...first time ever...suffer from an odd "pulsation" which even effected a few of the 12 volt lights inside the trailer.

after my "what else is going to happen" reaction, I realized by process, that it was not working right, and took the fuse out of line to shut it down.

I would like to suggest this is an important symptom, but both before it began to go odd, so to say, and afterwards, all the other symptoms existed and remain...and taking it off line stopped all that funny business with the lights...so my belief is that this may well have been a result of messing with the system to install the new batteries...maybe the fuse holder after sitting there for over 7 years.....but that it is not a central issue since disconnecting it did not change the main problem.

So in truth, I am not positive what it said at various times, as indeed, I never really paid a lot of attention to it, given that for 7 years, this system was working well.

I read your whole note and to the extent I am learning fast about all this.................also my tech is super and a good and honest man...and I am in the relative middle of nowhere, so such help is not readily avialable after him........is also now unwell with some serious, albeit curable issues...but I have not had him available to me in the interim and that has been a problem too as I have medical issues which make easy things not so easy for me, depending (among them five hand surgeries and that is not the worst of it so you can get the picture)...........................and as a person who is not unfamiliar with things "electric' although the trailer eco system has not been, from a learning perspective, my priority until recently....................to wit, I am an amateur radio operator for many years........everything you say makes completel sense to me.

that said, as mentioned previously in case it may have been lost in my volume of words, two sets of four BB batteries each have been tried here (I have 8 batteries in total) and all eight batteries...two sets of four....show the same issues when in the system....eliminating in my mind, the possibility of one BMS failure somewhere, etc.

IOW, fwiw, I agree with you on your analysis, but do not have a clue what that might be. i don't have a clamp on meter (my tech does...<sigh>...but fwiw, I do have a good fluke VOM. if the tech is not able to come here this week....I will ask him to lend me his...as I looked into this and a good one (fluke) is extremely expensive.....4 figures. that said, if you know of one which is acceptable in quality but not a couple of thousand...although at this point, I am prepared to do just about anything.....and can justify it with "who knows what the future holds", .....................I will do what I have to...so pse give me your opinion if you don't mind.

I have gone thru my mind, every appliance that I have in this box, and I just am seeing nothing which appears to indicate some problem which would be causing a constant load. indeed, as I have said, I have shut down the solar part of my life, simply to eliminate all I can, anything which might be causing an issue...and as you know from my total lack of brevity, here, I have tried two different 2812s, as well as two different magnum panels as well.

so I am on hold for a few more days in the meantime, waiting on my poor tech with his problems.......but that said, it has also been suggested that after hooking up the busbars...again, my sense, too, is that that won't change things but by process of elimination..............that i also try the CC/CV settings on the magnum.....so as I work through this list, I have that option as well.

as to your comment about bearing with you, please....don't think twice about that. I am literally grateful for the help here and the good news is that at the moment shore power is working, I am not in an emergency where I have to leave and take the trailer with me (my life circumstance, even at this age....in my 70s....is such that that remains a possiblity, although I hope I am done traveling......so for the moment, this is a nasty and elegant problem, but I am suriviving it, at risk of the appearance of melodrama in the way I put this.

so kindly take your time so you don't have my full weight on you ...and I am thankful in advance for all your thoughts...as well of all others.

this is a fine place to vet such things and every poster's responses have been fully welcome on this end...direct or not as the case may have been or be.

I will stand by for your comments about a clamp ammeter and then take steps to do something more.

thanks again.

ps do you find it odd that the voltage drop always stops at 13.2 or 13.1 and stays there for a while......many days if I keep the charger on standby......until it finally drops below 13 volts?

also, as I indicated previously, but repeat just in case....we did measure that the voltage at the 2812 mirrors the voltage reading seen at any given time, on the magnum panel....that was done before I replaced the panel with a new one, just in case....but that was, indeed, what was happening.

also, if memory serves, I did check for voltage drops on one set of the two battery sets and found nothing taking any battery below 13.6 volts. i have learned that it is a characteristic of some BB batteries that after a full charge they may, in fact, indicate a higher than 13.6 volt state (13.6 being BB's own definition of a fully charged battery) but they all seem to eventually revert to the common norm if left long enough. for example, one battery indicated after an IP65 charge, that it had, again if memory serves, 14.2 volts or so....I also supplied all these pieces of information to battleborn and they found nothing amiss with anything I was seeing........but i did notice that it came down over a few days to get back under 14 volts.

finally, I sent the cvs file generated by the IP65 from victron, to BB and again, they examined it...it involved one of the two sets of four batteries......and found nothing odd in the charging process and the final results.

 

[HRTKD]

The cheapo clamp on meter that I keep in my RV is no longer available, so I can't recommend it. Here is one that came to the top of the list when I searched on Amazon:

https://www.amazon.com/Multimeter-Auto-ranging-Temperature-Capacitance-Plusivo/dp/B08MTY51R4

It doesn't have to be this one. The key is that it MUST be capable of "DC current".

 

[HRTKD]

ps do you find it odd that the voltage drop always stops at 13.2 or 13.1 and stays there for a while......many days if I keep the charger on standby......until it finally drops below 13 volts?

also, as I indicated previously, but repeat just in case....we did measure that the voltage at the 2812 mirrors the voltage reading seen at any given time, on the magnum panel....that was done before I replaced the panel with a new one, just in case....but that was, indeed, what was happening.

Here's a screenshot of my two BMS dashboards. The batteries had recently completed a charge and were sitting at or above 14.0 volts and were being slightly discharged. So I do think your situation is odd. If I were looking to blame the batteries, one way that they could be the problem is if they weren't really charged to full 100% state of charge. A battery that was charged to only 15% might act like yours. When you charged each battery individually, how long did it take to do each one?

 

[olmz]

again, and I hate to keep saying this...this being "if memory serves" as that is, I know, less than precices, but if memory serves as I have done so much here, on some kind of average, the batteries...all 8 of which had been simply sitting, waiting for this or that...inside the trailer so temps were always "living temps" and not extremes...............one to two hours or so to fully charge each according to the ip65.

also, i had that very thought too, about "not taking a full charge" from the 2812 I had in the trailer since new...7 years....so I replaced it with a backup unit I had...purchased about a year and a half ago and sitting stored since then....and the problems remained....convincing me, if with no other evidence, that the 2812 I had in there was not the problem. indeed, I subsequently sent it to an authorized magnum facility, and they ran it thru its paces and found absolutely nothing wrong with it. what is in there now, is the newer one...which has exhibited no symptoms of any problems, either.

that said, implicit in this process was also that while both units have firmware considered current by magnum, they were manufactured roughly 6 years apart, so the firmware was different.......again, it did not affect the issue...the newer one has presets for Lion batteries but using them as opposed to custom settings did not change anything.

also, by way of explanation, if it helps, while the batteries were sitting...one set of four for about two years but approx once yearly I also charged each one.....the other set since last fall....but also charged with that IP65......they were not under any kinds of loads. fwiw, I intend to install a second, fully independent and redundent solar system in this trailer...the panels are already up (LGs) and I purchased a range of victron products for this second one....multiplus II, 12 volt, et. al.......again, it will not be plumbed into the main system in this trailer but will stand alone with its own outlets, etc...but that is the reason I have 8 and they all sat for a time.

 

[olmz]

The cheapo clamp on meter that I keep in my RV is no longer available, so I can't recommend it. Here is one that came to the top of the list when I searched on Amazon:

https://www.amazon.com/Multimeter-Auto-ranging-Temperature-Capacitance-Plusivo/dp/B08MTY51R4

It doesn't have to be this one. The key is that it MUST be capable of "DC current".

i have just ordered that clamp meter per your link. I am glad to see that you find something in that price range, to be acceptable and it is supposed to be delivered here tomorrow. thank you!

 

[MisterSandals]

Looking at the battery wiring, its not clear exactly how it is wired but i suspect it is wired from one end and not evenly utilizing all 4 batteries.
Such wiring is in the pic in this post #4:

Calculation of parallel string battery currents

Hi, everybody! I'm a retired EE. I didn't want my EE skills to fade away after retirment, so I exercise them when I can. Whenever I see a non-trivial circuit analysis problem on one of various forums I frequent, I challenge myself to solve it. Recently I watched Will's video about current...

diysolarforum.com

Solutions to wiring that fully utilize 4 batteries by including all of them in the charge and discharge current paths are in post #4. The top one is easy to wire, the second "perfect" one is difficult with wires and better suited for bus bars:

Calculation of parallel string battery currents

Hi, everybody! I'm a retired EE. I didn't want my EE skills to fade away after retirment, so I exercise them when I can. Whenever I see a non-trivial circuit analysis problem on one of various forums I frequent, I challenge myself to solve it. Recently I watched Will's video about current...

diysolarforum.com

Does this look like it might pertain to your battery wiring currently? It would explain how/why not all 4 batteries get charged.

 

[olmz]

Looking at the battery wiring, its not clear exactly how it is wired but i suspect it is wired from one end and not evenly utilizing all 4 batteries.
Such wiring is in the pic in this post #4:

Calculation of parallel string battery currents

Hi, everybody! I'm a retired EE. I didn't want my EE skills to fade away after retirment, so I exercise them when I can. Whenever I see a non-trivial circuit analysis problem on one of various forums I frequent, I challenge myself to solve it. Recently I watched Will's video about current...

diysolarforum.com

Solutions to wiring that fully utilize 4 batteries by including all of them in the charge and discharge current paths are in post #4. The top one is easy to wire, the second "perfect" one is difficult with wires and better suited for bus bars:

Calculation of parallel string battery currents

Hi, everybody! I'm a retired EE. I didn't want my EE skills to fade away after retirment, so I exercise them when I can. Whenever I see a non-trivial circuit analysis problem on one of various forums I frequent, I challenge myself to solve it. Recently I watched Will's video about current...

diysolarforum.com

Does this look like it might pertain to your battery wiring currently? It would explain how/why not all 4 batteries get charged.

thank you.

I am sorry but am not sure I understand your entire post. this wiring..and I don't suggest you are not correct, but rather just making the point, was given to me by Battleborn and it has been looked at by more than a couple, never mind here, and it has all been blessed......again, I am not saying anything but that.

the only thing not shown in the picture are the wires....two...positive and negative....that are going up thru the top of the battery compartment, and then connecting to the magnum 2812, with, of course, a fuse....400 amps........a magnum fuse, indeed, and sized per their reccomendations......spliced into the positive side before connecting to the magnum unit.

would you mind, please, elaborating a bit and telling me exactly where you think the problem is and why these in parallel for 12 volts are not wired correctly? again, I am not challenging the assertion, just don't understand it.

many thanks.

 

[MisterSandals]

exactly where you think the problem is and why these in parallel for 12 volts are not wired correctly?

I was hoping that the first 4 posts in that thread explained the problem and solution.

I will attempt a greatly simplified interpretation:

When batteries in parallel are wired from one end like this:

The charge and discharge mostly goes thru battery 4 which is the shortest and easiest path of resistance. This causes the bulk of charging and discharging to go to battery 4. If measuring voltage during charging from battery 4, its likely that battery 3 will be charged less, battery 2 charged even less and battery 1 the least.

By connecting positive and negative charge and discharge leads to different ends (positive on battery 4 and negative to battery 1 commonly called "diagonal wiring") for example, it passes current thru all 4 batteries.


As post 4 illustrates, this is not fully balanced either and offers increasingly better wiring.

Have you read thru the first 4 posts of that thread?

 

[olmz]

Looking at the battery wiring, its not clear exactly how it is wired but i suspect it is wired from one end and not evenly utilizing all 4 batteries.
Such wiring is in the pic in this post #4:

Calculation of parallel string battery currents

Hi, everybody! I'm a retired EE. I didn't want my EE skills to fade away after retirment, so I exercise them when I can. Whenever I see a non-trivial circuit analysis problem on one of various forums I frequent, I challenge myself to solve it. Recently I watched Will's video about current...

diysolarforum.com

Solutions to wiring that fully utilize 4 batteries by including all of them in the charge and discharge current paths are in post #4. The top one is easy to wire, the second "perfect" one is difficult with wires and better suited for bus bars:

Calculation of parallel string battery currents

Hi, everybody! I'm a retired EE. I didn't want my EE skills to fade away after retirment, so I exercise them when I can. Whenever I see a non-trivial circuit analysis problem on one of various forums I frequent, I challenge myself to solve it. Recently I watched Will's video about current...

diysolarforum.com

Does this look like it might pertain to your battery wiring currently? It would explain how/why not all 4 batteries get charged.

thanks.

no, I had not read that post. sorry.

I have attached the wiring instructions I had to begin with...this is how it is wired. I am still taking in all you posted in that other thread, but if the point is not to simply take the pos and neg wires going to the charger, from the same battery, but to do so in such as way as to, to use my words, "create a full loop through which the charging current is going and involving all four batteries, then I appear to have been directed correctly.

is that your conclusion?

 

[WindWizard]

I was hoping that the first 4 posts in that thread explained the problem and solution.

I will attempt a greatly simplified interpretation:

When batteries in parallel are wired from one end like this:

I enjoyed reading about the various battery connections and I am glad you pointed that out. The thing about the charging is that it is variable. Referring to the first diagram, granted Cell 4 takes most of the brunt of it due to the fact that it is being constantly charged and discharged at a higher rate than the other cells but once cell 4 gets charged then the other cells charge rate goes up and then eventually all the cells are fully charged. Yes I agree that there are better ways to wire 4 batteries together, but I do not think it explains what is going on.

 

[olmz]

Hello all,

I was asked by one poster here to post photos of the present wiring, so here are 5 shots....the way things are right now and have been through this problem......of the batteries, wiring in the compartment. I hope this are sufficient but if not, kindly let me know.

I have also sent these shots on to others not on this forum and so far, all have found no problems with the wiring, and in any event, this is how we were told to wire them when we started.

I do have two victron busbars and after I get done with the voltage measurements and as soon as I can get a tech here, we will hook them up and take pictures as well.

the consensus is that the busbar will likely not fix the precipitous voltage drop I am reporting on every charge cycle.....kindly keep in mind that every one of these batteries tests perfectly well on its own.....individually charged before putting them on line, with a victron IP65....all charged properly and ended up at voltages that were appropriate...and I remain ABSOLUTELY CERTAIN that all bukl, absorb and float charges...are correct as "custom" settings in the magnum 2812 for these BBs, per, indeed, even Battleborn's own site..

as you will see in pohoto labeled 0011.jpg, there is a lot going on on that terminal, and that one spot is the main reason we are going to try busbars and simplify things at that terminal...what a pleasant surprise it will be if that fixes this, although it would still beg the question as to "why".

i can also see how busbars will simplify all this in any event, and presuming they will not cause any resistance problems of their own, I intend to leave them there and just hook up this and that to the busbars.

anyway, again, thanks SO MUCH for all your brainpowers!

oliver

Either tonight or tomorrow, I will take voltage measurements as requested here, as well.......and kindly stand by for those.

I continue to appreciate everyone's help and time.

one more image. it was indicated here, in so many words, that not seeing where these wired went from the battery compartment, made it more difficult to understand the total picture. attached, then, is a picture of the compartment above the batteries, where the wires attach to the magnum 2812. I hope and trust that this is helpful....with continuing thanks to all.

 

[MisterSandals]

then I appear to have been directed correctly.

is that your conclusion?

Yes, that diagram shows diagonal wiring, which is reasonably good.

Yes I agree that there are better ways to wire 4 batteries together, but I do not think it explains what is going on

I was not sure what was causing OPs issue (either). After seeing the pics, i wondered if wiring was part of the problem; it did not appear to me to be all of the problems.

But OPs diagram, if followed correctly is good enough.

 

[MisterSandals]

granted Cell 4 takes most of the brunt of it due to the fact that it is being constantly charged and discharged at a higher rate than the other cells but once cell 4 gets charged then the other cells charge rate goes up and then eventually all the cells are fully charged.

This is true given a sufficiently long absorption time or sufficiently slow (low C rate) charge cycle.

With this in mind and moving to other areas, i am wondering about what the actual charge profile is set to? I am not familiar with the Magnum 2812 (nor any Magnum inverter charger).

ps do you find it odd that the voltage drop always stops at 13.2 or 13.1 and stays there for a while......many days if I keep the charger on standby......until it finally drops below 13 volts?

It would be very interesting to see the individual battery voltages with no loads or other connections to verify the. I understand it would be perhaps too much effort to confirm this curiosity. Is it possible to disconnect the battery (lower right switch in latest pic) and measure the voltage after an hour when you see the reading "below 13 volts"?

And...
A quick search reveals a thread that talks about 2 programable profiles (silent and float).

Silent charge or float?

I have a Magnum MS1212 2000w / 100A 12v inverter-charger in my motorhome. By batteries are a couple of drop-in 460Ah packs for a total capacity of 920Ah I am trying to decide which charge profile to use with I am plugged into a full hookup site. I have two programable profiles that should...

diysolarforum.com

Can you confirm your charge profile and settings?

Sorry i have so many questions. Just trying to follow clues and what i recall about dealing with other/similar issues.

 

[olmz]

Yes, that diagram shows diagonal wiring, which is reasonably good.


I was not sure what was causing OPs issue (either). After seeing the pics, i wondered if wiring was part of the problem; it did not appear to me to be all of the problems.

But OPs diagram, if followed correctly is good enough.

i am glad to hear that as I am still in learning mode......

thanks for having a look and letting me know.