1 hour ago, Daniel128 said:

Good morning too all

 Thank you for all the feedback and advice I really appreciate it.

 I did some fault finding this weekend and did some changes and it looks like it has paid off.

 I also got my hands on a load tester and tested all the batteries and all of them look to be in good order.

 I also disconnected all my batteries and charged them all to full capacity with a C Tec charger and left them for a couple of hours to settle.

 Did final testing to make sure all of the batteries are full and did read the same or as close as possible and re connected them.

 I also put new connectors on all of my cables and left the system to charge the howl Sunday and to go into float to balance them all off.

 On the inverter AXPERT 5KVA in program 29 low DC cut off voltage I see it is set to 42v would you recommend I change it to 48v because that’s where my batteries read 50% discharged but I have read it interferes with the soc?

Yes, the Axpert doesn't read the SOC right, if you change the values to 48V. So, if you want to do that you would need something like a BMV 702 and use something like AICC or SolarMon to manage your system. 

I would rotate the batteries every few months, and I suggest you keep log of each battery's drain and charge levels on a regular basis. 

3 hours ago, Daniel128 said:

On the inverter AXPERT 5KVA in program 29 low DC cut off voltage I see it is set to 42v would you recommend I change it to 48v because that’s where my batteries read 50% discharged but I have read it interferes with the soc?

No, don't set it to 48V. 

48V or 12V per battery is in your case a SOC of 50% under no load condition. (The exact voltages differs slightly between battery brands and types etc.)

If the inverter needs to supply a load and current is drawn from the batteries the voltage might drop to way below 48V while the SOC might still be much more than 50%. The higher the current drawn from the batteries, the lower the voltage reading will be - that is determined by the internal resistance of the batteries. Once you remove the load from the inverter the battery voltage will rise and stabilize at a higher value, depending on the SOC at that moment.

As discussed many times before on this forum and others, the Voltronic inverters use battery voltage to determine the SOC of the battery bank and that is unfortunately not the best method and is very inaccurate.  A more accurate method to determine the SOC of the battery bank is to make use of a proper battery monitor and that is why so many people on this forum refer to the Victron battery monitors e.g. the BMV702.

To get back to the low DC cut-off voltage, do not change it to 48V, because your inverter will trip under load while the SOC of the battery bank is still fine, rather leave it on 42 V and invest in a proper battery monitor and use the battery monitor to control the load or inverter at a specific SOC.  If you feel very uncomfortable with 42V, set it to 44V then, but it might still cut out unnecessarily.

Agreed. The DC cut-off is a safety mechanism and should be set to 10.5V or 11V per battery, or 42V - 44V.

Your back-to-grid voltage can be set to 48V (when the inverter decides batteries are done for and we need to go back to bypass mode). You can use voltage in a sort of makeshift way for this, if you know your typical load.

For example, I know that under my typical load the batteries are at 75% SoC when the voltage drops below 24.7V on my 24V bank, so I have my back-to-grid voltage set to 24.7V. That gets me roughly a 25% DoD. This only worke because I know my typical loads. Anything out of the ordinary (such as the weekend when I had a 100W orbital sander running until after dark) and it will switch to grid sooner, because the higher load drops the voltage despite the SoC being good.

Agreed, if you want to be "safe" and be sure, then only go to 44V. I have a similar setup (although not with the nice batteries you have), and the Victron battery monitor (BMV702) always tells me it is 85+ percent  when the Axpert/Voltronics unit hits the 46V mark (usually only 92%). You do have 2 settings though, so rather set the "normal" change over (when utility available) at 46V and the "cut-off" at 42V (when utility not available).

Even under load, no normal battery should be submitted to under 10.5V (12V battery) for longer than about 2 minutes, you will kill it. Only exceptions at the moment are the Edison Iron batteries which no-one can afford

I have Victron AGMs at the moment. Lovely batteries but maybe 1000 cycles at this DoD. Second hand deal from a UPS when company moved offices. Otherwise I'd never use an AGM for this.

Sent from my GT-I9195 using Tapatalk

Hi Chris - my installer from what I'm seeing from you post - the inverter + and - goes from the first string say the plus from the last sting to the - and the installer just paralleled all 5 strings onto one battery bank - hence only actually giving me 102a/h - which would explain the battery loss at night.  I have 20 x 102/ah batteries which is coupled up in series to give me the 48v - from there each bank is joined in parallel - which is the then the + and - of just one battery bank in effect which will only give me 102ah apposed to 510a/h - am I correct

I correct

38 minutes ago, Pacmanmb said:

I have 20 x 102/ah batteries which is coupled up in series to give me the 48v

1 string of 4 each = 102ah at 48v (4 x 12v) per string - perfectly normal
5 strings of 4 each = 510ah - which is nice.

Now MY opinion:
The problem comes in with the 5 strings as balancing 20 batts would be quite a severe challenge, if at all possible, even with balancers.

Not keeping them all in sync, i.e. too many strings in parallel,  inevitable leads to premature replacement of the bank, or at the very least, a reduction in usable strings.

And it can become dangerous as some batts overwork, dry out and basically starts shorting - therein the balancing. So feel the temps by hand, under load / charging, regularly per battery or even per pole. If one batt is getting warmer, that string has a problem.

Always better to get the least amount of batteries for the required AH. For example J200RE's are 12v 200ah batteries.
So 1 string of 4 of them is 200ah at 48v
2 strings of in parallel is 400ah

Balancing 8 batteries instead of 20 using balancers ... much easier and perfectly acceptable.

This installer did not do right in my opinion. 

 

 

 

 

23 hours ago, The Terrible Triplett said:

1 string of 4 each = 102ah at 48v (4 x 12v) per string - perfectly normal
5 strings of 4 each = 510ah - which is nice.

Now MY opinion:
The problem comes in with the 5 strings as balancing 20 batts would be quite a severe challenge, if at all possible, even with balancers.

Not keeping them all in sync, i.e. too many strings in parallel,  inevitable leads to premature replacement of the bank, or at the very least, a reduction in usable strings.

And it can become dangerous as some batts overwork, dry out and basically starts shorting - therein the balancing. So feel the temps by hand, under load / charging, regularly per battery or even per pole. If one batt is getting warmer, that string has a problem.

Always better to get the least amount of batteries for the required AH. For example J200RE's are 12v 200ah batteries.
So 1 string of 4 of them is 200ah at 48v
2 strings of in parallel is 400ah

Balancing 8 batteries instead of 20 using balancers ... much easier and perfectly acceptable.

This installer did not do right in my opinion. 

Thanks for that advice - but the main question is why I cant hold charge - after the battery banks were installed took about a week to get them to float. Durning the day is now a problem on sunny days as the panels run the borehole ,pool pump and heatpump. I have put priority breakers so none of these big items can run together. on average I have about 800w draw from late afternoon and that's just tv's etc when lighs off current is about 300w but this entire bank is at cut off voltage. So came to the conclusion these batteries are not connected the way they should be - all banks are 48v - but I suspect not stringed correctly, but I have not had a chance to check of as yet. I am going to have to remove the entire ban this weekend to see what is happening and how it is stringed up. the first thing I noticed or what I have seen the charge controller must negative from last sting and positive to the first string to give equal balancing across all the banks - or visa - versa. I've only had the system for 6 months - so all the help would be appreciated .

23 hours ago, The Terrible Triplett said:

 

 

 

 

 

Thanks for that advice - but the main question is why I cant hold charge - after the battery banks were installed took about a week to get them to float. Durning the day is now a problem on sunny days as the panels run the borehole ,pool pump and heatpump. I have put priority breakers so none of these big items can run together. on average I have about 800w draw from late afternoon and that's just tv's etc when lighs off current is about 300w but this entire bank is at cut off voltage. So came to the conclusion these batteries are not connected the way they should be - all banks are 48v - but I suspect not stringed correctly, but I have not had a chance to check of as yet. I am going to have to remove the entire ban this weekend to see what is happening and how it is stringed up. the first thing I noticed or what I have seen the charge controller must negative from last sting and positive to the first string to give equal balancing across all the banks - or visa - versa. I've only had the system for 6 months - so all the help would be appreciated .

 

46 minutes ago, Pacmanmb said:

I am going to have to remove the entire ban this weekend to see what is happening

Ideally you need to test each battery separately, load test each one with Hawkins testet the same ones they use at car battery shops. 

Another quick test, when the bank is discharging / charging, try and feel each batteries pole / casing. Any battery hotter than the rest, disconnect that string out immediately, take it offline.

48 minutes ago, Pacmanmb said:

... but the main question is why I cant hold charge ...

Am quite sure you will get batteries that are problematic, dead, the main cause being  the 5 strings. That is what too many strings do.

48 minutes ago, Pacmanmb said:

... after the battery banks were installed took about a week to get them to float ...

That is not, was not good. That could be another reason, added to the 5 strings, why the bank is now damaged.

50 minutes ago, Pacmanmb said:

So came to the conclusion these batteries are not connected the way they should be - all banks are 48v

Nope, it is because of 5 strings and probably incorrect charging.

If it is an Axpert, did you upgrade the firmware to fix the charge bug?

It is an axpert - currently running v72.9 but t I know this firmware is giving me problems with other funny stuff - all the batteries have been load tested and are fine - and even when on full load these batteries don't even get warm - what software version should I be looking at - also running the icc software 

28 minutes ago, Pacmanmb said:

It is an axpert - currently running v72.9 but t I know this firmware is giving me problems with other funny stuff - all the batteries have been load tested and are fine - and even when on full load these batteries don't even get warm - what software version should I be looking at - also running the icc software 

On the Axpert I cannot even begin to help. 

The load testing, being 100ah batts, did each one take the 200-250amps draw, keeping in the green of the testers dial, all 20 of them?

If so, then their is something else potting ... 

The 5 strings are still not advisable at all. Lower your load and keep max 3 strings connected.
Keep the other 2 strings on charge and use them later to replace the others in the future ... or something along those lines.

 

Edited February 6, 20197 yr by Guest

On 2019/02/07 at 6:03 AM, Pacmanmb said:

It is an axpert - currently running v72.9 but t I know this firmware is giving me problems with other funny stuff - ... what software version should I be looking at - also running the icc software 

I have a theory that firmware version 72.90 only comes with clones. Could you post a picture of the sticker on the side of the inverter, or follow the steps in this post (just the one above the first photo [ edit: you should now use Do I Own a Clone? ] ). Your mention of "other funny stuff" only strengthens my theory.

Edit: however, this post (in Italian) seems to disprove my theory. Sigh. If you have a genuine machine, you could update to patched firmware version 73.00e (or later, if that ever happens). It's unclear whether you will run into error 90 after 6 months if you update to factory firmware version 73.00. If you do, you should still be able to downgrade to factory firmware 72.70, or update to patched factory firmware 73.00e. If you have a clone, you might be able to update to 73.00e; some clones don't seem to have a bootstrap loader. If you need to parallel with 5 kW machines that come with firmware version 74.XX, then you can't run 73.XX, factory or patched.
 

See also: Can I update my firmware, and if so, to what?

Edited February 17, 20197 yr by Coulomb
Use "Do I Own a Clone" link.

Thanks for all that - I haven't run into error 90 or any error since I have had the unit. The only problem that I have is no apparent reason the inverter kick to utility for the slightest increase in power usage - eg switches to utility if you switch another tv on which draws about 150w - during the day I have to shut off utility power just to make sure I get the optimum out of solar. I have in total 15 x 275w panels and the way I have configured my DB board cannot draw more than 2kw - all the big power users are on priority switches. If upgrading this unit will help with that willing to try that as well the only problem is how do I do it and where do I find that firmware. I would assume you do that off a laptop - or via watchpower, but watchpower does not upgrade

Had the same problems with a so-called axpert with S/N barcode number (Always check the barcode should be 14 number digits , digits no 5-8 is the year and month of manufacturing if not don't buy ) .  It would also switch to utility for no reason and disconnect the solar PV many times a day . No support from supplier . Had to replace the SCC to solve the problem . 

Sorry to say, but that label doesn't look genuine:

• Should be 14 digit serial number, starting with 9293 for a 5 kVA model, and as @Chris Louw says above, the date code should be YYMM (yours appears to be YYYYMM)
• Use of the ¢ (cent symbol) instead of the ϕ (Greek letter phi symbol)
• Label is too close to the mounting screw, and there is no small date sticker over the nearest cover screw. The screws should be black, not silver.

None of this is totally conclusive, but it doesn't look good.

Thanks for all that - I have maybe come up with a solution and would like help from you guy's out there - since 5 stings seems to much for my system and been advised that I have a clone system. to try the following. Buy a proper Axpert system to run my home and use 8 x batteries - 2 strings to run the house with 15 X 275w panels. Add the clone inverter - works fine during the day without any problems with 6 x 275 panels and with the other 12 batteries - 3 strings just as charge control for the batteries - use the clone inverter then to supply the proper inverter with backup power if required instead of Eskom. Same goes with the clone inverter - will then get it's backup from Eskom - sort of a revolving credit card system but with power. Any ideas or not a good one. I have spent a lot of money on these batteries, which are only 8 months old - so would rather use them in more effective manner. During the day the solar does the max of the work unless there is bad weather - on average only use 2- 10kw of Eskom power per day and the draw from solar/battery is about 40kw per day and that's running a borehole, pool pump and heat pumps - but all that runs during the day. 

Also where can I get the latest software/firmware for these inverters - I actually don't think it is a clone - just relabelled from the manufacturer - as I see the serial number is sticked on over the original

Been waiting to see where you thoughts would go re. the 5 strings.

1 hour ago, Pacmanmb said:

2 strings to run the house with 15 X 275w panels.
... clone inverter - 6 x 275 panels and with the other 12 batteries - 3 strings just as charge control for the batteries
...use the clone inverter then to supply the proper inverter with backup power if required instead of Eskom. 

102ah "leisure deep cycle" (they are not deep cycle) batteries tend to last +-5 years on standby - very infrequent use - like in UPS'es.
They could have about 250-350 cycles to 50% DOD, maybe 400-500 to 10% - I would guess.

So if your goal is to keep them for powering through infrequent failures, that is a good move.

Get a proper Axpert, update the firmware and all that. Keep all you panels on it.
Don't use batteries if you can help it.
Get a BMV 702.

Or ... to get some ROI on the batts you have bought, use them alternatively and very lightly, or even at night, by making them easily dis-connectable / connectable. For that light use, you get ICC and set it to use the batts lightly like a SOC not below 10% between X and Y hours.

Now because the 5 strings are the problem and we all know the inverter must have at least 1 string connected to operate, get a 10 x connectors like this below, called a Brad Harrison / Anderson Connector. This one is a 50amp connector. You get 175amp ones too.

So what you do with these connectors:
You install a busbar connected to the inverter with 5 of these connectors on there. 
The other 5 on each string of 4 batts.

Inverter must always have 1 string connected to work, right, so you can easily keep just one connected and dis-connect the other strings. 
Or you can have all 5 strings connected to the inverter in a dire emergency.

Now you set up a schedule where you connect X strings as you need them to recharge, top up, run daily, and disconnect the other ones.
You can leave a charged battery bank easily for up to +-6 months if you want. So call it you change the disconnect strings every 2 months.

You goal is to evenly use them over the next 4.2 - 6 years to get the best use out of them.

If this makes sense, keep the clone as backup inverter, connection to the same busbar as the Axpert and connectors are on, that you can switch over easily.
Same with the array. Put connectors on the cables that you can swap the array between the Axpert and the clone in seconds.

Just a thought.

4 hours ago, Pacmanmb said:

Also where can I get the latest software/firmware for these inverters

You could start here: Can I update my inverter, and if so to what?  In your case, you'll have to ignore the warnings about not attempting to update clones. I have a theory that some of the clones don't have a bootstrap loader, just a jump instruction to the main firmware. These can't be updated at all, since the loader is needed for firmware updates. It won't hurt to try; if there is no bootloader, then the ReflashTool simply won't do any updating. Cycling the battery power to the inverter should bring it back to normal.

But certainly, some clones have been updated successfully (assuming that these really were clones, of course, but I'm fairly certain that they were). Good luck.

Thanks - that was most informative - now the next question is where can the software from as I cant find  it anywhere ?

On ‎2019‎/‎02‎/‎09 at 11:36 PM, The Terrible Triplett said:

Been waiting to see where you thoughts would go re. the 5 strings.

102ah "leisure deep cycle" (they are not deep cycle) batteries tend to last +-5 years on standby - very infrequent use - like in UPS'es.
They could have about 250-350 cycles to 50% DOD, maybe 400-500 to 10% - I would guess.

So if your goal is to keep them for powering through infrequent failures, that is a good move.

Get a proper Axpert, update the firmware and all that. Keep all you panels on it.
Don't use batteries if you can help it.
Get a BMV 702.

Or ... to get some ROI on the batts you have bought, use them alternatively and very lightly, or even at night, by making them easily dis-connectable / connectable. For that light use, you get ICC and set it to use the batts lightly like a SOC not below 10% between X and Y hours.

Now because the 5 strings are the problem and we all know the inverter must have at least 1 string connected to operate, get a 10 x connectors like this below, called a Brad Harrison / Anderson Connector. This one is a 50amp connector. You get 175amp ones too.

So what you do with these connectors:
You install a busbar connected to the inverter with 5 of these connectors on there. 
The other 5 on each string of 4 batts.

Inverter must always have 1 string connected to work, right, so you can easily keep just one connected and dis-connect the other strings. 
Or you can have all 5 strings connected to the inverter in a dire emergency.

Now you set up a schedule where you connect X strings as you need them to recharge, top up, run daily, and disconnect the other ones.
You can leave a charged battery bank easily for up to +-6 months if you want. So call it you change the disconnect strings every 2 months.

You goal is to evenly use them over the next 4.2 - 6 years to get the best use out of them.

If this makes sense, keep the clone as backup inverter, connection to the same busbar as the Axpert and connectors are on, that you can switch over easily.
Same with the array. Put connectors on the cables that you can swap the array between the Axpert and the clone in seconds.

Just a thought.

Really appreciate all the help - what is the best advice on the number of strings at most - generally during the day it not an issue - just the evening and even then the max draw is about 900w with a peak of maybe 2kw with the microwave - after 10 or so drops to about 300w at most - found out today that my setup is way off with this load shedding - with 20 x 102ah deep clycle gel batteries - gave me a total of 4 hours power. So am going to pull them all out and start from fresh from tomorrow. Start with one bank or maybe 2 and then take advice from you guy's with battery balancers and busbars - but I still would like to try the double inverter charging system

@Pacmanmb , work your loads, panels and all that out with this Excel calc.

Let me know what the results are?

 

(15) Solar Panel Design(1.1.17).xls

11 hours ago, Pacmanmb said:

now the next question is where can the software from as I cant find  it anywhere ?

? The first post of the thread has links to all the various firmware zip files. All the software you need is in there. For hardware, you need a Windows machine and a USB to RS232 adapter, as well as the serial cable that came with your inverter.

On ‎2019‎/‎02‎/‎12 at 4:58 AM, Coulomb said:

? The first post of the thread has links to all the various firmware zip files. All the software you need is in there. For hardware, you need a Windows machine and a USB to RS232 adapter, as well as the serial cable that came with your inverter.

From your experience what would be the best firmware to upgrade to - have tested all batteries and have now ordered bus bars etc per advice and switch units. Just upgrading the firmware is an issue if something goes wrong - or can I recover from that. So many versions - which is the most stable that you know of