Hey All

Hope this has not been covered before. If so I have not found it. I would be happy to be directed to threads with the same or similar advice!

I bought a  Mecer/Axpert inverter (VP MKS 3K)

4 x 105Ah lead calcium batteries (Gel all sold out everywhere), connected series parallel.

3 x Renewsys Deserv 255W Solar Panel (24v)

I installed this 2 weekends ago in a small cabin which I do not stay at other than weekends. For this reason I am not always there to monitor why it is not charging the batteries except for this weekend when there was almost no sun.

I installed this all myself, with the solar panels connected parallel. At the inverter I am getting 25v out of the Solar Panels on a bright day, but I still get nothing on the Inverter display or the WatchPower software.

I downloaded the Axpert Settings 1.1 From Chris Hobson (thank you a godsend). Which gives a much clearer idea of what the setting do. That said I have not been around it long enough to monitor the charge and discharge of it. So dont know what to expect and when.

At this stage I cant tell if I am not getting charge as it is "FULL" or if the inverter is not charging the batteries. I go back out next weekend and would like to be armed with more info to interrogate.

Posted is also the WatchPower screenprint.

Any advise would appreciated.

Regards

Stephan

 

I think your charging voltages are to low, once you add calcium the charging voltage requirement is higher than normal lead acid.

About 14.8V for a 12V cell.

 

2 hours ago, phil.g00 said:

I think your charging voltages are to low, once you add calcium the charging voltage requirement is higher than normal lead acid.

About 14.8V for a 12V cell.

I think you can work on increasing all voltage set points by  0.4V  per 12V cell, above the standard LA battery settings as a starting point.

See where that gets you.

You will have to change the battery type to User to change the float and absorb (etc) voltage settings.

You might also be affected by the premature float bugs. If so, since there is no patched firmware for 24 V models, you might try setting the Charging time in CV mode (settings page) to 60 minutes. This doesn't fix the problem, but forces a longer time before the float stage is reached.

Are you sure that your full model name has both VP and MKS in it? VP is the Axpert code for PWM, but MKS is the Axpert code for MPPT.

What is the maximum Voc rating for your inverter? (It's written on the large sticker on the side).

Are your panels in series or parallel?

Good Morning!

Wow! Did not expect a response so soon.

Panels are in parallel. With very little voltage drop at the inverter.

I am not with inverter today, but confirmed with supplier it is an MPPT charge controller.

The Voc Is 37.98V for the panels.

Thanks again for the effort! Appreciated!

Stephan

Good Morning!

Wow! Did not expect a response so soon.

Panels are in parallel. With very little voltagm

On 2019/04/27 at 12:46 AM, phil.g00 said:

I think you can work on increasing all voltage set points by  0.4V  per 12V cell, above the standard LA battery settings as a starting point.

See where that gets you.

phil.g00 what is meant by LA battery settings? 

On 2019/04/27 at 5:27 AM, Coulomb said:

You will have to change the battery type to User to change the float and absorb (etc) voltage settings.

You might also be affected by the premature float bugs. If so, since there is no patched firmware for 24 V models, you might try setting the Charging time in CV mode (settings page) to 60 minutes. This doesn't fix the problem, but forces a longer time before the float stage is reached.

Are you sure that your full model name has both VP and MKS in it? VP is the Axpert code for PWM, but MKS is the Axpert code for MPPT.

What is the maximum Voc rating for your inverter? (It's written on the large sticker on the side).

Are your panels in series or parallel?

Coulomb, I did not see that setting on the inverter menu. Are you referring to watchpower?

 

Thanks again for the help!

Stephan

1 minute ago, StephanS said:

phil.g00 what is meant by LA battery settings?

I mean bog standard lead acid car 12V battery settings, silver calcium lead acid requirements are about 0.4V above these per 12 Volts.

3 minutes ago, StephanS said:

Coulomb, I did not see that setting on the inverter menu

Setting 05, Battery Type. Default is AGm, you want USE.

3 minutes ago, StephanS said:

Are you referring to watchpower?

No, but if you have Watchpower working, you should be able to change the settings from there too.

Thanks for the reply Coulomb!

I let someone run the batteries down to the previous screen print settings. But for whatever reason the batteries have not seemed to recharge given these settings.

Attached is another screen print with the current charge. The solar panels are doing well with 25.5V but 0W.

To me it makes no sense.

Thanks again for the help

Stephan

Edited May 14, 20197 yr by StephanS
No file

20 minutes ago, StephanS said:

Attached is another screen print with the current charge.

So your Battery Type is Flooded, but it looks like that gives you the maximum charge voltage of 29.2 V (unless yours is a special model that will go to about 32 V). So it should be charging.

Quote

The solar panels are doing well with 25.5V but 0W.

Um, what makes you think that 25.5 V is good? You'll need at least several volts more than the battery voltage, and at the top of the charge, this will be 29.2 V. 25.5 V sounds like battery voltage leaking through the Solar Charge Controller. Is it possible that you have PV fuses blown or not connecting properly?

Each of your 60-cell panels should show about 30-35 V with no load.

How many panels do you have, and in what configuration? (I.e. all 3 in series, or all 3 in parallel).

What is the maximum PV voltage for your inverter? I'm not as familiar with the 24 V models, and some models seem to have very small Solar Charge Controllers (600 W).

Is yours an MPPT or PWM model?

Many of these questions can be answered with a photo of the large bar-code sticker on the side of the inverter.

3 in parallel 37.89V Voc

The charge controller is 600w version.

Here are the specs

Input

• Voltage : 230 VAC
• Selectable Voltage Range
• 170-280 VAC (For Personal Computers)
• 90-280 VAC (For Home Appliances)
• Frequency Range : 50 Hz/60 Hz (Auto sensing)

Output

• AC Voltage Regulation (Batt. Mode) : 230VAC ± 5%
• Surge Power : 6000VA
• Efficiency (Peak) : 93%
• Transfer Time : 10 ms (For Personal Computers); 20 ms (For Home Appliances)
• Waveform : Pure sine wave

Battery & AC Charger

• Battery Voltage : 24 VDC
• Floating Charge Voltage : 27 VDC
• Overcharge Protection : 31 VDC

Solar Charger & AC Charger

• Maximum PV Array Power : 600 W
• MPPT Range @ Operating Voltage : 30VDC~ 66VDC
• Maximum PV Array Open Circuit Voltage : 75VDC
• Maximum Solar Charge Current : 25A
• Maximum AC Charge Current : 30A
• Maximum Charge Current : 35A (AC charger and solar charger can’t work at the same time)
• Maximum Efficiency : 98%
• Standby Power Consumption : 2W

2 hours ago, StephanS said:

3 in parallel 37.89V Voc

Ok, so you need to find out why you're measuring 25.5 V, not 35+ V.

Someone needs to get sunscreen and hat on, and get on the roof with a multimeter 🤠

On 2019/05/14 at 12:06 PM, Coulomb said:

Ok, so you need to find out why you're measuring 25.5 V, not 35+ V.

Someone needs to get sunscreen and hat on, and get on the roof with a multimeter 🤠

It is because of people like me that I hate forums! 

I thought about lying to hide my stupidity...

I went up disconnected everything measured them separately getting 35v on relatively cloudy day. Connected it all back up and still had an issue...

Then I realised I had temporarily connected a 21v solar panel (on the ground and not in same location)also in parallel to charge the (12v) batteries individually while I installed the solar panels on roof. 

I total forgot that I had the spare old panel connected. It was only when you said I was getting leakage that I realised the problem (although I was convinced I had removed it)

Since the batteries 24v batteries had been run dead flat, I am assuming they were unable to charge more than the 21.6v of the 12v panel.

Once I disconnected the panel it all was good...

That's my version and I am sticking to it!!!

Coulomb, thanks for the help, really appreciated.

Great responses from Coulomb...im inspired sir