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Axpert Ac Charge "leaking"


PaulF007
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Hey guys. 

Since I got Eskom on the farm I could take a bit of strain off my batts but now there seems to be a Charge "Leak" when I am on UTL mode at night. 

My settings is as follow:

11 - Util - 2a

16 - OSO

So according to my sources it should not be charging at night but as you can see from the graphs there is a constant 29 to 30 watt charge going into the batts. 

2017-03-21_073218.thumb.png.5f807bfa3228f3f1278c1c7cd82c4d8c.png

ZOOM View:

2017-03-21_074536.thumb.png.377c021b33f14ca363c85c96aa765a40.png

 

Anyone else have , had this before? @Coulomb ? :D

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If  Program 16 is set to SOL then it will charge from grid in the absence of PV energy. I think Paul's hassle is he is cycling his batteries lightly and because of the 40W trickling in there is not much for his charger to do in the morning. With it set to OSO there should be no grid charging.

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  • 2 weeks later...

Hozid Guys

I rechecked the settings again and it all seems ok , but still no luck. Every time I switch over to grid the batts gets a trickle charge , stays on 40 w until the solar pannels gets activated then it goes over to them even if I still stay on the grid. 
@Coulomb would the updated firmware maybe help for this? 

Best regards

Paul

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No, I can't see why the patched firmware would help with this. Are you sure this is real current into the battery, not current from the inverter / charger supplying losses? As I type this, it seems unlikely. 

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Hi @Coulomb

The inverter it self does not "pick" up that there is current going out to the batts, the only reason why I could see it was that the BMV picks it up.

2017-04-04_193839.thumb.png.0263773fc72d5fc49d31ec37ec43a1bf.png

Battery amps is the BMV feed see its fairly low , only about 0.57 a . So this could be a hardware issue?

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I'll keep your problem in mind for when I get time to read the firmware again. In some places, it is using tenth of an amp resolution; in others, whole amps. It may be that it can't control the current to less than one amp. But there is the option of disconnecting the charger / inverter completely, and it sounds like that's what you need. When the current is leaking in, does the LCD display show the utility charger active? I.e. A box between the utility "tennis ball" and the battery icon, with power flow lines between? 

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13 hours ago, PaulF007 said:

the only reason why I could see it was that the BMV picks it up.

Battery amps is the BMV feed see its fairly low , only about 0.57 a . So this could be a hardware issue?

Disconnect the battery from the inverter - pull the battery fuse / open the isolator - then monitor the BMV and check if it still picks up current flowing. 

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1 hour ago, superdiy said:

Disconnect the battery from the inverter - pull the battery fuse / open the isolator - then monitor the BMV and check if it still picks up current flowing. 

Unfortunately the Axpert cannot function disconnected from the battery. Perhaps check for current flow with a DC clamp multimeter. My Axpert show a small draw when I copy Paul's settings.

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2 hours ago, Chris Hobson said:

Unfortunately the Axpert cannot function disconnected from the battery. 

That's ok, the BMV will still work without the Axpert running. You'll need to read the BMV's small screen though, as your monitoring software won't work without the Axpert running. 

Edit : also, a clamp meter reading DC will have a significant offset that will likely confuse the issue. 

Edited by Coulomb
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4 hours ago, superdiy said:

Disconnect the battery from the inverter - pull the battery fuse / open the isolator - then monitor the BMV and check if it still picks up current flowing. 

 

22 minutes ago, Coulomb said:

That's ok, the BMV will still work without the Axpert running. You'll need to read the BMV's small screen though, as your monitoring software won't work without the Axpert running. 

Edit : also, a clamp meter reading DC will have a significant offset that will likely confuse the issue. 

Lying on my bed with a tummy bug. SuperDIY proposal makes sense now whereas I did not grasp his train of thought earlier.

 

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On 04/04/2017 at 7:43 PM, PaulF007 said:

Battery amps is the BMV feed see its fairly low , only about 0.57 a . So this could be a hardware issue?

I am wondering whether your BMV's calibration might be out. How close to the negative pole is your shunt mounted? What is your battery voltage whilst this charge is trickling into your battery bank (Both BMV and Axpert readings)?

 

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My BMV was out and was showing also current to batteries while the charger was off. Reseted it and working fine now

Sent from my SM-G920F using Tapatalk

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  • 2 weeks later...
On 4/6/2017 at 9:10 AM, Manie said:

My BMV was out and was showing also current to batteries while the charger was off. Reseted it and working fine now

Time and weather has finally gave me the opportunity to test this and true behold after disconnecting EVERYTHING except the the BMV itself there was still a positive feed into the batteries. So I zeroed the BMV and it now seems ok , at least I am not charging the batts with thin air :) .

Unfortunately this raises a brand new question , much have been discussed as to how batteries must be cared for and a lot of our decisions is been benched on the info that we receive from the various monitoring devices. I assumed that the BMV will "know" when there is energy flowing through the shunt but I was wrong! I have to tell it when there is no energy and then it can work from there.So can we rely on most of these monitoring devices? 

Even with something like a BMV , that costs a fair amount of money , there is still a lot that could go wrong. 

  • You have to tell it how big your Bank is - get that wrong and your SOC is in ist glory in
  • You have to tell it when there is no energy flowing - In my case i had a "extra" 1a going into the batts it stands to reason that at discharge the readings would also be out and also the SOC. 
  • Maybe we should get the slim ouens here give us a "guide" - Similar to what @Chris Hobson did with the Axper settings - as to how to setup the BMV so that it can measure the batteries properly.

Regards

Paul

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Just now, edmundp said:

BTW - what weather station are you using?

I am using the Oregon Scientific WMR88 with cumulus to upload the data. Good value for money but don't get the 90 as they have changed the protocols on that one. Doesn't seem like some one managed to crack it sofar or rather say when I looked at it the last time. 

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56 minutes ago, PaulF007 said:

Those parameter settings are "too easy" for new batteries to achieve. The tail value is too high and the detection time too short. You will find that the BMV will jump from 95-96 to 100% with those values.

1.) Check you actual float voltage when the batteries are fully charged. Set the Charged Voltage setting on the BMV 0.1 V lower than your actual float  voltage.

2.)You need to check your actual tail current and set the tail current to just above the "actual tail current" when the batteries are fully charged.

3.) Then stretch the detection time for as long as possible, which is 50 minute for the two settings above to be met met, before going to 100%.

4.) Then do a manual synchronization to tell the BMV, this is 100%. Then it knows in future where to auto synchronize. 

The best I can get mine down to is 98%, then it jumps to 100%.

soc100.thumb.JPG.26191d5b6b6dad01fcc1e41ad34f52ac.JPG

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I am using the Oregon Scientific WMR88 with cumulus to upload the data. Good value for money but don't get the 90 as they have changed the protocols on that one. Doesn't seem like some one managed to crack it sofar or rather say when I looked at it the last time. 

I use the same station but use Cumulus software as it it has alot more features...

Sent from my SM-G800F using Tapatalk

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