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SOC (State of Charge) never getting to 100%  RSS feed

 
pollinator
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Set up a new system recently with the following components:

Outback Power MPPT Charge Controller 80 amp
Magnum 4400 Watt, 48V, Parallel Inverter/60 Amp
Magnum Router controller
Battery monitoring kit
8, Surrette 428 Amp Hour Batteries
6 solar panels totalling 2000 Watts

The only problem we've had is that the SOC (State of Charge) that the BMK (Battery Monitoring Kit) calculates is never getting to 100%. It always says "Thinkn" which the manual says means it still hasn't reached the conditions needed to be at 100%.
Its been several weeks now with lots of sun and very little power being used as the owner is not using the house yet.
The Charge controller says its going through all the stages of charging and normally ends with 2-3 hours of it being in float mode. So to me, its saying that the batteries are fully charged.
Went through all the settings several times to ensure all the correct figures have been entered. In particular the BMK requires the amp hour size to properly calculate the SOC.

Magnum Energy is hard to get in contact with so I thought I'd try here first.

Has anyone run across this happening to them? Any suggestions?  Thanks!


 
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Personally I never want my batteries to reach 100% charged.

To go from 50% charge to 75% charges takes 25WHr and will give me 24.5WHr during the discharge.
To go from 0% charged to 25% will take 50Whr and will only give me back 24.5WHr that is why it is a waste to let your battery go below 50% and esp close or at 10%.

To go from 90% charge to 100% charge will only give us back 10WHr (more like 9.8Whr) but it will take 30WHr+ to get it there a complete waste of energy, at least that is my belief.
I have exaggerated the numbers a bit, but hopefully you get the general idea, that it isn't linear but more of an exponential curve,the constant charge and discharge is bad for batteries you might have remembered your laptop battery giving you a similar warning a few years back. So it is possible that the BMS/electronic is purposely not bringing and keeping it at 100%
 
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Tough it out with magnum... Just work through the setup with them to rule out mistakes. I find about 10 or 11 am eastern time mon Tues weds work best. Some basics: Battery size is programmed in correctly? The absorb voltage numbers are equal to those suggested by the manufacturer? Absorb time is right for bank size? You've run a bulk, absorb, float run with the genny. Temp sensors are installed midway down the battery case taped to an inside battery?  I've seen it "thinking" for 24 hours before. I'm not a fan of state of charge... with our climate the cold seems to throw off the state of charge readings. So all winter with lack of absorb time and temperature affecting how well the batteries absorb it goes wonky.  Personal opinions of course...
 
Gerry Parent
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Hi guys,  
Some interesting views. I know in the magnum manual it says:
"Note: Battery SOC is a more accurate method than using battery voltage as a criteria to determine when a battery requires charging."....and this is why I was interested in it. So if SOC and battery voltage can't be trusted then what parameter would I use to gauge the true battery bank capacity?

S Bengi said "So it is possible that the BMS/electronic is purposely not bringing and keeping it at 100%".
Not sure about this as I have helped set up another (smaller) system that also use the SOC parameter and it does get to 100%. I have also read in the manual that its best to bring the batteries to 100% approximately once a week to help keep the SOC parameter accurate.

I will give Magnum another try during those hours you suggested David.
"Battery size is programmed in correctly?" - Battery size is entered into the BMK settings which for us is 430Ah.
"The absorb voltage numbers are equal to those suggested by the manufacturer?" - Yes, both into the inverter and the charge controller
"Absorb time is right for bank size?" -  It was set for 1 hour then we switched it to 2 hours to see if it would help but did not. I will look into this further though.
"You've run a bulk, absorb, float run with the genny. " - Havn't done this yet as we just hooked up the AGS just a few days ago...will try it.  
"Temp sensors are installed midway down the battery case taped to an inside battery?" - I'll double check today,
"I've seen it "thinking" for 24 hours before. I'm not a fan of state of charge... with our climate the cold seems to throw off the state of charge readings. So all winter with lack of absorb time and temperature affecting how well the batteries absorb it goes wonky." - I thought the temperature sensor was supposed to compensate for this? Guess not eh?



 
David Baillie
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I go on battery voltage alone for the ags settings. We have tried soc triggering but it just never seems to work as well and consistantly as the voltage trigger. Your ags should be your last resort. The smart human in the mix controlling genny time is always a better solution. Just remember to turn it back to auto when done!!! (Most common reason for ags fail)
As to why it misrepresents I dont know.  Battery specs have different absorb settings based on temperature so I'm not sure the compensation range is enough if the settings have not been seasonally adjusted. We generally set bank temp indoors at 20c. If someone is really keen on their system and the batteries are outdoors well teach them how to adjust seasonal values... Batteries are a dark art... they are chemical and alive not electronic.
 
Gerry Parent
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I think I have it figured out why the BMK never gets (or ever will get) to 100%.

The only settings that can manually be entered in to program the BMK is charge efficiency (which I set to "auto" position) and Ah size of the battery bank which I set to 430ah.
When I went to look at the inverter controller (ARC) under the "meters" heading it gives all kinds of info about what the BMK is reporting. The 2 listed below are the ones that are very wonky (and that I think are the cause of the problem)

5D   DC amps BMK   +1011.6 ADC
5E   AH  In/Out           +32767 Ah

5D is supposed to report the real-time amps coming and going from the battery (and has a range of 0.1 - 999 amps) . Where is it getting this crazy high number coming from? (Interesting that it actually goes over the range of the unit !?!)
5E is supposed to report the total of incoming and outgoing amps (The range is ┬▒32,768 AH) . If we only had this unit up and running for only less than a month now with very little use of power, again, where is it getting this crazy high number from? (Interesting how it matches the maximum range of the unit !?!)

So either the unit is defective and needs to be replaced or something is hooked up incorrectly (highly unlikely since its a pretty simple setup)

Any thoughts?

 
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Gerry Parent wrote:I think I have it figured out why the BMK never gets (or ever will get) to 100%.

The only settings that can manually be entered in to program the BMK is charge efficiency (which I set to "auto" position) and Ah size of the battery bank which I set to 430ah.
When I went to look at the inverter controller (ARC) under the "meters" heading it gives all kinds of info about what the BMK is reporting. The 2 listed below are the ones that are very wonky (and that I think are the cause of the problem)

5D   DC amps BMK   +1011.6 ADC
5E   AH  In/Out           +32767 Ah

5D is supposed to report the real-time amps coming and going from the battery (and has a range of 0.1 - 999 amps) . Where is it getting this crazy high number coming from? (Interesting that it actually goes over the range of the unit !?!)
5E is supposed to report the total of incoming and outgoing amps (The range is ┬▒32,768 AH) . If we only had this unit up and running for only less than a month now with very little use of power, again, where is it getting this crazy high number from? (Interesting how it matches the maximum range of the unit !?!)

So either the unit is defective and needs to be replaced or something is hooked up incorrectly (highly unlikely since its a pretty simple setup)

Any thoughts?



Those numbers cannot be correct. Even if 5E was an accumulation of amps in and out, in one month there is no way it would add up to 32 thousand amps.  I would like magnum to further clarify those numbers.

I will say, I finally killed my first set of batteries.  6 years of terrible abuse.  One thing I have learned, the battery "fuel gauge" is wrong will not tell you the correct SOC.   It ALWAYS will be wrong.   They can get close, but they are never spot on right. There is too many variables especially charging efficiency as the batteries age. I like my fuel gauge, but I would never use it as a sure thing. Second thing.  Guessing SOC based on battery voltage is always wrong also.  Third thing, guessing SOC based on hydrometer readings is always wrong.  4th thing, guessing SOC with a refractometer IS actually correct SOME of the time lol.

Refractometer readings are really the way to go if you truly want to know the SOC.  You do need to know what the manufacturer of the battery says is the specific gravity of the electrolyte, most are 1.275 fully charged but a lot of heavy duty batteries are actually 1.265 fully charged, this equates to less sulfuric acid in solution and longer battery life at the expense of less "on demand" energy.  

The only times I've found refractometer readings wrong are when electrolyte levels drop from water evaporation, leading to higher S.G. and When you top the batteries off with water, the S.G. is artificially low because the electrolyte stratifies for several days.

I think you'll find if you check your batteries S.G, they will be quite low.  I would recommend to bump your absorption time to 4 hours, pre programmed into the outback this time is far far too low.  The only downside to high absorption time is the batteries use more water, a much better thing to do to batteries then staying undercharged constantly, what s. bengi suggested would be really detrimental to battery life.  Lead acids need to stay as charged as possible.  

 
Gerry Parent
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David,    I agree with your statement for every machine in life "The smart human in the mix controlling genny time is always a better solution."....I mean if all humans were "smart" then judement day would never happen right? (sorry, bad Terminator reference)
The owner prefers the convenience of the AGS, so we'll do our best to make it as accurate as possible automatically even if it could be made more efficient by including a human in the mix.

Eric -   "Refractometer readings are really the way to go if you truly want to know the SOC." First off, I didn't realize how inexpensive they are. Might have to pick one up.... Not quite as convenient as a hygrometer but from my days of using one to find the best sugar content of maple trees I do agree they are accurate. Unfortunately, the SOC is needed on a daily basis and having to use a refractometer for that would really suck. Relying on the SOC of the BMK is one of the main reasons it was purchased so I guess its inaccuracies are just going to have to be accepted and intervene with hygrometer or refractometer readings occasionally to make sure we're still in the ballpark of keeping our batteries topped up properly.

"I would recommend to bump your absorption time to 4 hours, pre programmed into the outback this time is far far too low."  I'll do this once the owner actually starts to use power.

Just can't wait to call Magnum on Monday morning and listen to that recording a million times saying how important our call is and that were next in the que...

Thank you both for your input. I'll let you know what comes of all of this.
 
David Baillie
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Gerry, we had a bmk acting that way. it ended up being a faulty unit. We changed all the components. It was 4 years old though so no warranty. Apply a known load to it and see what its amps out reads. I usually have an amp clamp multi meter on the battery wires when I do this. Ours was 40 amps out...  And again trigger the ags on voltage not state of charge. The magnum does better that way. Set its turn on voltage to whatever you choose, set the clock at 3 or 4 minutes to avoid nuisance starts, turn the off voltage all the way up to float to avoid conflicts. Absorb time... While a long absorb time will add more to the batteries it comes at a high cost in fuel usage as the efficiency goes down as they approach full. Its a balancing act between battery health and genny lifespan and fuel usage.
 
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Also, set it to run with straight charge control settings instead of soc. Id almost divorce the bmk and just use the arc if it is determined to not be wiring or other.

You will not want two inverters (2 right?) charging units boiling stuff and id be sure it is staying below battery max amps in that mode if it applies. It should, but id run the test.

I use SG and return amps over time to establish absorb time. The usual starting point is 1 hour for every 100ah capacity at the 20hr rate. This is not usually going to work for various reasons and tuning is required.

Magnum may use a different rate and all needs to be equivalent.

Return amps at full is sometimes published and can usually be found as .02├Ścapacity ah/20hr.

20/hr rate is an important figure and is most widely used as a common measure. Not always and rolls nameplate is at an odd rate for reference for size.  20hr rate will need to be found to use these rough calculations.

If return amps with no load and SG reasonably jive together and performance is suitable, there is the reference for full.

With soc based charging you still need to adjust efficiency percentage or other offsets to tune it up, so with flooded batteries you should have a way to measure electrolyte levels. You will still need to use a hydrometer, refractometer or deal with short life span and lowered capacity over the useful life of the battery, which can also work.

I think ec on a per cell basis is starting to be practical.

Absolutely the temperature compensation values need to be correct one way or the other, auto or manual.

You will never have perfect charging. Close is the target. (I love it Eric!)





 
frank li
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Im also in for waiting for tech support. Re read everything and go over it again, trace wiring (power, shunts and comms) check dip switches, jumpers and settings. Align voltage for the controller(s) and re check t-comp.

Then call the number..... most every time i have called, its been tracked back to something i missed in the manual or an accessory manual i did not read!

Carefully stir the cell electrolyte with a turkey baster type syringe, then take readings. Charging helps, but readings stabilize when mixed gently to break stratification.
 
Gerry Parent
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One update so far. When I reset the BMK by pulling the power then plugging back in, that 5E AH In/Out resets to 0, then almost immediately starts counting in +1 amp increments very quickly. I now see this is so because its thinking that there are 1011.6 amps coming in (no way) x 120V = Ah. So in about a day or so, it reaches the maximum amount of (32767 Ah) that it can record then just sits there. So the question remains....why is it reporting all those incoming amps when they don't exist? Perhaps the shunt is bad? Any way to test it?   Still trying to get a hold of Magnum....

5D   DC amps BMK   +1011.6 ADC
5E   AH  In/Out           +32767 Ah
 
frank li
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You can test the shunt it is printed with its resistance. Tech support will likely have seen this. Wiring, settings then component failure diagnosis if no other cause is evident.
 
Eric Hammond
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Gerry Parent wrote:One update so far. When I reset the BMK by pulling the power then plugging back in, that 5E AH In/Out resets to 0, then almost immediately starts counting in +1 amp increments very quickly. I now see this is so because its thinking that there are 1011.6 amps coming in (no way) x 120V = Ah. So in about a day or so, it reaches the maximum amount of (32767 Ah) that it can record then just sits there. So the question remains....why is it reporting all those incoming amps when they don't exist? Perhaps the shunt is bad? Any way to test it?   Still trying to get a hold of Magnum....

5D   DC amps BMK   +1011.6 ADC
5E   AH  In/Out           +32767 Ah


Edited to correct a terrible amp vs volt mistake

Its REALLY HARD to test a shunt. A simple resistance check won't do. The resistance is really low. The battery monitor is measuring voltage drop across it.  I have 2 500 amp shunts rated at 50 millivolts meaning if 500 amps were flowing through it, battery voltage being 24 volts to it, 23.950 would come out of the shunt  At normal amperage draws of 1-100 amps, the amount of voltage drop would be negligible at best.  The battery monitor is basically a volt meter with its positive and negative leads on each side of the shunt to use voltage drop to calculate the amps flowing through it based on the predetermined value of the shunt.

Double check the shunts mV rating!!!  You need a specific mV rating for your battery monitor!  The shunt should be stamped.  Double check that it's right with the battery monitor literature. Otherwise I would suspect a bad battery monitor
 
Eric Hammond
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There is one other thing to think about. The wires from the battery monitor to the shunt should be twisted to prevent radio frequency interference from being induced into the circuit.  Make sure they are not routed next to any a/c voltage lines.  If that's ok, shut off the inverter and evaluate, they can produce RF also.
 
frank li
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Eric Hammond wrote:


Double check the shunts mV rating!!!  You need a specific mV rating for your battery monitor!  The shunt should be stamped.  Double check that it's right with the battery monitor literature. Otherwise I would suspect a bad battery monitor



I think this is more likely than a defective shunt or a defective monitor. The shunts are one of the highest quality and most stable and trouble free parts in the system. True it takes creativity to test a shunt without lab equipment set up to do so or a swap check..... didnt think about that until you said it, never had to test one!
 
David Baillie
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frank li wrote:

Eric Hammond wrote:


Double check the shunts mV rating!!!  You need a specific mV rating for your battery monitor!  The shunt should be stamped.  Double check that it's right with the battery monitor literature. Otherwise I would suspect a bad battery monitor



I think this is more likely than a defective shunt or a defective monitor. The shunts are one of the highest quality and most stable and trouble free parts in the system. True it takes creativity to test a shunt without lab equipment set up to do so or a swap check..... didnt think about that until you said it, never had to test one!


Ive had to swap out two and both times it was the bmk module not the shunt. This is totally Magnum's domain odd you are having that much trouble. I usually get through within 20min or get a call back within an hour...
Power through it...
 
Gerry Parent
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David,   Contacted Arizona Wind & Sun today (the people we bought most of the system from). They were unsure of the solution but recommended to check that all loads are connected on the opposite side of the shunt from the batteries. I highly doubt that this is the source of the problem but will double check.

Frank,   I have a feeling that its not the shunt as well (just a gut feeling) but am going to switch the cables (one being longer than the other) so that the shunt is a close as possible to the batteries.

Eric,   The cables you mentioned are still twisted together all the way from start to finish. They included about 5' of twisted cable which I wrapped in a coil. To see if this was causing a problem I uncoiled them and made them straight while watching the meter....no change. Also, shutting off the inverter did not do anything as well.
We also have a 500 amp shunt rated at 50 millivolts which came with the Battery monitor as a kit.
The BMK is still under warranty so gonna cash in on that one pretty soon if nothing else comes up.
 
Gerry Parent
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Double checked that all loads ARE connected to the side leaving the shunt.
This was the only day where we turned off the inverter and the BMK amp reading was not at   +1011.6 ADC  but crept down about 5 amps. Then when we unplugged the power from the BMK for about a minute then plugged back in it was down to around 980amps. Thought I was onto something but then when I tried it again, it went back up to +1010 ADC.

Also, "5G Total AH OUT" has been at 0 ever since all this started and never moves. Even when the inverter and charge controller was off it still didn't move.

Got a hold of Magnum on the phone today and they said to check the milliamp reading between the orange and blue wires. We checked them on the shunt (0mV), where they attach to the BMK (2.3mV) and then disconnecting the harness from the BMK and checking again (0 mV). To me they should have all been the same but weren't.  
 
Eric Hammond
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Gerry Parent wrote:Double checked that all loads ARE connected to the side leaving the shunt.
This was the only day where we turned off the inverter and the BMK amp reading was not at   +1011.6 ADC  but crept down about 5 amps. Then when we unplugged the power from the BMK for about a minute then plugged back in it was down to around 980amps. Thought I was onto something but then when I tried it again, it went back up to +1010 ADC.

Also, "5G Total AH OUT" has been at 0 ever since all this started and never moves. Even when the inverter and charge controller was off it still didn't move.

Got a hold of Magnum on the phone today and they said to check the milliamp reading between the orange and blue wires. We checked them on the shunt (0mV), where they attach to the BMK (2.3mV) and then disconnecting the harness from the BMK and checking again (0 mV). To me they should have all been the same but weren't.  



Hey Gerry, sorry it wasn't something simple!  I'm a little confused by some of the readings you said, mostly because without pictures its not clear what your referring to.  Also, not to second guess you in any way, but I would like a picture of the meter screen when your make your measurements.  We are dealing with REALLY small amounts of voltage here and the measurements are critical.

First, you did install the shunt in the NEGATIVE battery cable correct?  Were the fasteners torqued with a torque wrench?

The following statements I'm about to say from an electrical engineer perspective is absolutely not true, however from layman's perspective like you and I, gives us a reference as to what must happen to get your scenario:

Your battery monitor is reading 1010 amps.  The shunt is rated for 500 amps at 50 mV and is calibrated to the battery monitor upon manufacture.  Given that information, we can assume in order to read 1000 amps, the battery monitor must see around 100 mV difference in voltage.

That's not much, and any poor connection could cause that easily.

My system is an outback, but a shunt is a shunt.  Here is how you can test if its a connection or the battery monitor.

You need to set your voltmeter up to read mV.  I highly recommend this specific meter for ease of operation and accurate results/ with cost in mind.  Your leads stay plugged into the common for black and volts for the red.  We must select the mV scale because we are going to read decimal places before 1 mV.  On this meter you place the dial at this postition, but you must press the yellow button at the top to select DC mV.  You'll notice there is enough static in the air get a reading with the leads not touching anything.



Leads touching each other should zero the meter.



Touch both of the leads to the each side of the shunt.  Polarity is irrelevant to us and we will disregard any minus sign.  You'll notice on my shunt, all the terminals were coated with a conductive electrical grease (NOT di-electric) and torqued, any resistance here make inaccurate amperage readings.



The reading across the shunt is .5 mV   or .0005 VDC



This equates on my battery monitor to about 5.4 amps  on a 24 v system


Follow those two wires back from the shunt and measure between them again were they connect to the battery monitor



The reading here HAS TO BE IDENTICAL to the first reading across the shunt


If the reading at the shunt is not identical to the reading at the battery monitor, we need to figure out the poor connection.

If the readings ARE identical, then we need to think about what reading we got.  Is the reading 50 mV? If so the battery monitor must read 500 amps.  If it reads higher, the monitor HAS to be bad

Is the reading 25 mV?  the monitor should be reading 250 amps and so on and so on.

If the amps on the battery monitor match what we are getting based on voltage drop of the shunt, IE, for your 1010 amp reading, we measure 100 mV or .1vDC across the shunt side to side, we are most likely looking at a poor connection at the shunt.

Does that make sense?  That should be enough info to pinpoint the culprit.  It's worth noting, Voltage drop only works with the circuit intact and functioning.  We cannot unplug anything to make measurements.
 
Gerry Parent
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Eric Hammond wrote:
Hey Gerry, sorry it wasn't something simple!  I'm a little confused by some of the readings you said, mostly because without pictures its not clear what your referring to.  Also, not to second guess you in any way, but I would like a picture of the meter screen when your make your measurements.  We are dealing with REALLY small amounts of voltage here and the measurements are critical.


I'll snap some photos today

First, you did install the shunt in the NEGATIVE battery cable correct?  Were the fasteners torqued with a torque wrench?


Yes, Shunt is on the negative cable but not secured with a torque wrench. Couldn't find any info in the setup about what torque to use....any suggestions?



You need to set your voltmeter up to read mV.  I highly recommend this specific meter for ease of operation and accurate results/ with cost in mind.


For now I'm using a cheap Home Depot special volt meter but will order one of those your using as I need a better one anyways.

You'll notice on my shunt, all the terminals were coated with a conductive electrical grease (NOT di-electric)


Could you include a brand name as I do have di-electric but not what your suggesting.

Does that make sense?  That should be enough info to pinpoint the culprit.  It's worth noting, Voltage drop only works with the circuit intact and functioning.  We cannot unplug anything to make measurements.


Yes it does make sense to me. I'll get back to you once I get more readings.
 
Gerry Parent
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Here are some pictures of our system and readings.... Let me know if there is something missing...
solar-system-overview.JPG
[Thumbnail for solar-system-overview.JPG]
1016-ADC.JPG
[Thumbnail for 1016-ADC.JPG]
ah-in-out.JPG
[Thumbnail for ah-in-out.JPG]
bmk-connected.JPG
[Thumbnail for bmk-connected.JPG]
bmk-disconnected.JPG
[Thumbnail for bmk-disconnected.JPG]
outback-charge-controller.JPG
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shunt-overview.JPG
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Eric Hammond
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The picture testing at the shunt, is that with the battery monitor plugged in?
 
Eric Hammond
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Gerry Parent wrote:

Eric Hammond wrote:
Hey Gerry, sorry it wasn't something simple!  I'm a little confused by some of the readings you said, mostly because without pictures its not clear what your referring to.  Also, not to second guess you in any way, but I would like a picture of the meter screen when your make your measurements.  We are dealing with REALLY small amounts of voltage here and the measurements are critical.


I'll snap some photos today

First, you did install the shunt in the NEGATIVE battery cable correct?  Were the fasteners torqued with a torque wrench?


Yes, Shunt is on the negative cable but not secured with a torque wrench. Couldn't find any info in the setup about what torque to use....any suggestions?



You need to set your voltmeter up to read mV.  I highly recommend this specific meter for ease of operation and accurate results/ with cost in mind.


For now I'm using a cheap Home Depot special volt meter but will order one of those your using as I need a better one anyways.

You'll notice on my shunt, all the terminals were coated with a conductive electrical grease (NOT di-electric)


Could you include a brand name as I do have di-electric but not what your suggesting.

Does that make sense?  That should be enough info to pinpoint the culprit.  It's worth noting, Voltage drop only works with the circuit intact and functioning.  We cannot unplug anything to make measurements.


Yes it does make sense to me. I'll get back to you once I get more readings.



16 ft lbs on a 3/8's course bolt should be good

The electric grease I use is XG-12 by motorcraft https://www.amazon.com/gp/product/B000NUBB28?pf_rd_p=c2945051-950f-485c-b4df-15aac5223b10&pf_rd_r=DCY616X5SB174RA91PH5
 
Eric Hammond
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In the simplest terms, judging from what I see, the battery monitor is bad.

(using Paul's numbering system)



12s)  The voltage drop of .1 mV seems right for the 2 amps coming in.

145)  The battery monitor being plugged in to the circuit should not increase the voltage in the circuit, making me think there is a voltage leak internally to it.

198r)  The very last picture tells me the monitor thinks amperage is always coming in to the battery all the time, and never leaving the battery at night, still charging through some miracle

23b)  The amperage of 1000 amps at 48v = 48,000 watts from the panels at night seems excessive  (this one was slightly a joke)

1s)  The 1000 amps is positive, meaning that's what it thinks is going in to the battery.  The shunt measures voltage drop across it to calculate amperage.  In order to figure whether that voltage drop into the battery or out of the battery, it does an open circuit voltage test of each side of the shunt basically.  In our example of 50 mV drop at 500 amps, say 48 volts,   If we are in a discharge state, voltage between the positive terminal and the battery negative terminal at the shunt would be 48 v, the opposite side of the shunt to B+ will read 47.950.   If we are in a Battery charging state, open circuit voltage B+ to battery negative side of shunt would be 48 and B+ to the opposite side of shunt will be 48.050   (these numbers aren't real obviously, but gives you how the battery monitor will interpret if we are in a charge state or discharge state)

26t)  That means in order for your battery monitor to read +1000 amps continuously, the side of the shunt away from the negative battery will always have .100 V DC more then the negative side, even at night, and that just cannot be possible

34d)  New parts are just untested parts

Based on this logic in my in-expert opinion I would replace the battery monitor.


I also at this point would like to razz you about the wire nuts, and that you should get rid of them, we aren't building a house ;)
 
Gerry Parent
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Eric Hammond wrote:The picture testing at the shunt, is that with the battery monitor plugged in?



Yes, plugged in....and thank you for link and torque needed.
 
Gerry Parent
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Eric Hammond wrote:In the simplest terms, judging from what I see, the battery monitor is bad.



OK, so no more fiddling needed until Monday when Magnum gets another call and hopefully they see it that way too and covered by warranty

(using Paul's numbering system)


Must have missed that podcast... care to fill me in on the logic/joke?

145)  The battery monitor being plugged in to the circuit should not increase the voltage in the circuit, making me think there is a voltage leak internally to it.


Yes, I agree. That's why I also took a picture of the monitor disconnected to show the difference.

198r)  The very last picture tells me the monitor thinks amperage is always coming in to the battery all the time, and never leaving the battery at night, still charging through some miracle X

23b)  The amperage of 1000 amps at 48v = 48,000 watts from the panels at night seems excessive  (this one was slightly a joke)


Now, if the rest of the system would also join into the free energy miracle, you and I could be rich.

I also at this point would like to razz you about the wire nuts, and that you should get rid of them, we aren't building a house ;)


HA!  I knew when I took some of these photos that was going to happen! Kinda like hanging up you wash on the line for everyone to see. As they say though:  "NO GUTS, NO GLORY".
The ones on the far left of the first picture were from the fellow that put most of the system together before I got here. The one that was pig-tailed into the bmk power supply was just to save another trip of wire to a battery - post. I know its not professional and pretty for now and probably will get upgraded once everything is working properly. Thanks for the slap!
 
Eric Hammond
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Paul seems to think that when multiple people start making lists of things throughout a post, when someone replies to item number 1, it's hard to tell who they are actually replying to.   By making your numbering completely different, there is no question who you are replying to.....there seems to be logic there for me
 
Gerry Parent
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UPDATE:  Magnum declared the BMK to be defective and are sending us a replacement. Fingers crossed.
 
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