stuvo

I reached out to Victron Solar and a very helpful local (Philippine) representative got back to me. He recommended the EasySolar model. After looking at the spec sheet, I agree. It is an amazing piece of kit that fits my needs perfectly.  I expected a big price difference ( X1.5 or double), but it's 4 times as expensive as a replacement Axpert clone. 
Axpert clone: USD 1132              Victron Solar EasySolar 48V: USD 4245
WOW, big difference. Now, I have just spent USD 60 for shipping and another USD 10 for a part that in a normal market should cost less than 1USD, and when it gets here may not even fix my inverter. In hindsight, I would buy quality Victron in the beginning,  but right now I am living my learning curve. 
Best case, the varistor replacement gets me another couple of years or so. 
I think the lesson here is, the further from civilization you live, the greater the quality your equipment should be for long-term use.
 

When you say "clone", do you mean a Voltronic manufactured machine that has a different name, or a look-alike that is made elsewhere? Perhaps a photo of the unit or of the sticker on the side, if it has one.
You're in a relatively hot climate in the Philippines, so I'd guess that the battery-side capacitors dried out and the MOSFETs blew. Especially if it's a non-genuine Axpert; they might have 85°C capacitors, which might only be expected to last a couple of years.
It's also possible that the extreme humidity caused inevitable dirt on the PCB to become conductive enough to cause a MOSFET to misfire and cause shoot-through. These MOSFETs have leads with 2.54 mm lead spacing, which I believe is too small.
Tell them to check the internet for repair hints. If they don't find and fix any faulty gate drivers, you could be up for some US$80 in parts and have them blow up again as soon as the machine is turned on again. Have them replace the battery side capacitors with long life versions as well.
The "damaged component" is likely to be at least 8, probably 16 MOSFETs. A mirror might reveal blown leads and/or cracked cases. You might even be able to see damage from outside the case, through ventilation holes. The MOSFETs are on an aluminium heat-sink, under an overhang that makes them hard to see from above while the main board is still in the machine.

The Error 4 is determined by the value of program 29 (Low DC cut-off voltage). I no longer have  vanilla Axpert firmware on my machine but If I remember correctly it is triggered when the battery voltage is 4V (or less) greater than the value in program 29. With @Coulomb's LFP firmware it is 1V greater than the value of Program 29.
 

Lengthening the wires should not be a problem. Of course when the balancer is working full tilt there will be a slight drop on the cable, but since the current redistribution is pretty much a function of how badly they are out of balance (which will never be perfectly the same) this variable drop is likely not accounted for in any case, even with the existing cables. I highly doubt it will matter.
Besides, when the batteries are in perfect balance, no current passes on the wires and the voltage drop will be insignificant. It's an entirely different scenario as the big fat ones that actually carry charging current!

Just to follow up:
I've been experimenting and I don't believe it was any load turning on that was causing my MPPT to reset. Today was completely sunny, not a cloud in the sky and I had no resets. I think it was intermittent cloud cover that caused the resets.
 
 

We discussed this before. All MPPTs do this. When you're not operating at the maximum available PV power, the charge controller isn't looking for the maximum power point because it doesn't need to. It sits there just balancing things so the battery voltage remains within bounds.
But if there is a change in loads, it doesn't even have to be a big one it just has to be big enough that the battery voltage dips a little, the MPPT will spring into action  and try to bring the voltage up, and this might cause the CC to go looking for the MPP.
To do that, many MPPTs will simply scan the whole range. They reset and start from zero.
My own particular favourite brand of MPPT does not do this. As the power demand increases it will adjust up to the nearest maximum point, and then it will do three or four quick scans on other voltages to find the best one and settle on that. Even that takes 30 to 40 seconds. See attached video on the CCGX. I increase the maximum discharge current and I send the MPPT hunting. After I enter the SetValue command on the terminal shell, you'll see the PV charger figure make a number of dives...
 

A variable load like a iron plays havoc with the MPPT. Sometimes it cannot adjust fast enough causing the MPPT to reset. What sort of load are you powering?
 

Sorry to butt in here. Just a suggestion. Why not install all your panels at the new building and run the axperts in parallel there? That would mean you'll have to install two cables ( one of which you would have done in any way) one to connect the axperts to the grid and one to supply the old building from the axpert's output? Way less losses that way and the advantage of having the axpert's in parallel on one battery bank. Pv can be split up between the two axperts then.

Sent from my S60 using Tapatalk

Hi Jacques
2 Axpert in parallel must share the same battery bank and so must be close together.
It is no problem to have a separate system in the new building on same AC supply because you are not feeding back into the grid with an Axpert so there is no chance of them interacting - obviously system2 should be connected directly to the AC supply and not from output of system1.

Hi Stuvo no problem. This thread comes out the Ark. It does show that we all started somewhere. Here I was asking advice and it's only a pleasure to pay it forward.
Your datasheet's  Bulk/Absorb voltage recommendation is a range between 57.6V and 58.8V. At 25°C this is  above gassing voltage which is 57.36V so I would opt for the lower end of the spectrum since the Philippines is tropical (just north of the equator). At temperatures of 35°C gassing voltage is about 56.3V. Operating at 57.6V rather than 58.8V means that you will go to absorb sooner and stay in absorb longer. Since you have 3kW of panels I don't think you will really notice the longer absorb time. It might influence you on a cloudy day but since the batteries are your biggest investment lets try and extend their life as much as possible. Float I would set at 54.4V (the lower end of the spectrum again with your higher temperatures in mind.
The voltages need to be compensated for the higher temperatures. I see Manila's average daily temperature is 30°C in May. The battery's datasheet gives a temperature compensation of 30mV/°C for bulk absorb and a 20mV/°C compensation for float. So at 30°C Bulk would be 0.6V lower at 57V and float would be 0.4V lower at  54V. At 35°C bulk would be 56.4V and float would be 53.6V
You can charge at up to 90A if you want to, since you have 3 strings of batteries and each string's maximum charge is 30A. Since you are charging OSO you are in fact limited to just under 60A. (3000W  of panels divided by battery voltage). With three strings I would use busbars for battery cables. Like the example below.

Three strings would look like this

I would also use SOL if it takes you batteries down to 85%. That gives you fair usage of your batteries without hammering them.
Now finally on to the BMV. Unfortunately each set of batteries is slightly different and it is just a matter of adjusting and seeing whether the SOC on the BMV is occurring at the appropriate time. Monitor how much charge your batteries are absorbing during float. With  a 300Ah battery bank I would say your batteries are full when the absorb about 150W or less. I have seen as little as 70W on my 260 Ah battery bank but that is after 2-3 hours on float. Look at BMV and get a feel of what constitutes 100% SOC. A charge of 3% or less of your Ah rating is considered by some to be 100% SOC (9A for a 300Ah battery bank). I find my batteries it is closer to 1%. If your BMV is showing 100% SOC too soon lower the tail current by 0.1% and observe for a couple of days. You may find for instance 2.8% is too short and 2.7% too long (as I did in my case). If so set to the higher value and then extend charge detection time.
I presume you are using the midpoint function of the BMV. Since you have a 48V system lower the alarm threshold (Program 47) to 1%. 2% is fine for a 24V system. Program 48 has to be then set to lower than program 47. I have mine set to 0.7%. The reason is that a given deviation will only register ½ the percentage deviation since the battery bank is operating at twice the voltage. For example a 0.5 V difference between the top and bottom of a 24V  system would translate to 2.1% deviation. The same 0.5V deviation which if it is the result of one battery is just as serious would only register as just over 1% deviation and would go unnoticed if program 47 is not adjusted. There is a detailed explanation on page 31 of the BMV 700/2 manual.
There is an awful lot to digest here so if anything is unclear just ask.     
 

Ok design looks like an MPPT model. So no worries there. The only difference I can point out right now is all the screws look different than those in other inverters I have seen.
I think best to wait till your supplier gets back to you. 
 

Different brands of batteries have different characteristics like charge current, discharge rates, bulk charging voltage and float voltages, resistance, etc.
It is not a good idea to mix new batteries with old batteries, even of the same brand. The new batteries would work a lot harder and you will probably end up overcharging the new batteries and undercharging the old batteries and therefore reduce the life of the new batteries.
Don't throw them away, find something else to do with them. If you use the old batteries with the new ones you will probably find that in 2 - 3 year's time you probably would have to throw away all 12 batteries. You will greatly reduce the life of the new batteries and not get the specified cycles out of them that you are supposed to.
As long as you can set the charge current high enough to be able to charge them properly, it is not a problem. The 100 Ah battery capacity is relatively low, so adding another 4 batteries should not be a problem.  
Add the new string of batteries and remove the old string of batteries.

@stuvo, switch off the inverter completely and switch it back on again - reboot the inverter. The inverter is like a PC and sometimes it gets confused and you have to reboot it to get it to think straight again. Start WatchPower and make sure the serial port is working. Check which port WatchPower is using. Exit WatchPower (Right click on the WatchPower icon and select exit) and start the flash program selecting the same com port. 

@stuvo, it looks like you're doing everything right with the software update process, at least from what we can see here.
I'm concerned about the 32.40 firmware, Either that is very old (the lowest number I have seen on a 5 kVA Axpert is 52.02), or the versions don't always increase with time, or it's custom, or it's not a Voltronics Axpert. I agree it would be very good to contact your supplier to see if they can provide a known compatible software update, or at least the update files for the existing firmware in case it's special in some way (and of course that you find some way to actually perform the update).
I could not find any Axpert model on the SMK website. However, the fourth scrolling picture on the main page shows what looks very much like an Axpert, but with no brand name at all. The title said "Hybrid Inverter Charger", which is strange because the Axpert isn't a hybrid. When I click on Hybrid inverters under Products, I get a completely different looking blue box with a black "slot" up the middle. When I download the catalogue PDF, the specs for the blue box do sound like that of an Axpert, except for the mains charging, which is limited to 30 A. That sounds like it might be old hardware, which is quite possibly not suitable for use with firmware version 72.XX. Perhaps not even firmware version 52.XX. Perhaps the uploading process was different back then. Perhaps you have been spared a "bricking" by this, intentionally or not. (If intentional, I would have hoped for some error message, perhaps "Your inverter is not compatible with this firmware, contact your supplier" or similar.)
Do you have a manufacturing date on your machine? On later models, it's on a small (perhaps 30 mmm x 10 mm?) label put over one of the case screws, so that they have evidence if/when you open the case.
The vibes I got from the SKM website are that they are an independent manufacturer, not a reseller. But perhaps they are content to resell into the Axpert market, not compete with their own product, at least for the present.
 
Edit: one final clue: the photo on the main web page hints at a heatsink on top of the unit. The top of modern units is smooth cover metal, no visible heatsink (the SCC heatsink is now entirely internal, for better or worse). Does yours have a finned heatsink at the top?

I see 2 issues immediately...
1.  I always have my Axpert set on Com1... its the best for the firmware updates and I think for the MPPT update its required.
2. I think the U1 firmware version is very old.  I would be very keen to check with the supplier as to what model Axpert this is before flashing the firmware AND also have access to this version in case you need to go back to it later!.
 

Re reading my last post. The only thing in common (other than the inverter) is the physical USB to serial adapter. It's a generic Prolific VID 067B PID 2303 rev 0300. This seems to be common adapter that I have seen mentioned in this forum, so again I'm at a loss. I'll contact the third party distributor I purchased the unit from tomorrow and see If I can get any info from them.

My guess is that COM1 isn't the USB to serial adapter. Is there another option for the serial port, i..e. if you clock the arrow at the right end of the "Serial" drop-down list box, are there any other entries in the list, other than COM1?
As for the the assertion failure from the SCC firmware update program, I have no idea, but it sounds like it's related to the serial port issue.
You said the existing firmware version was 32.40... could that have been a typo and it was actually 72.40? If it's not a typo, perhaps it's not a real Axpert, in which case all bets are off.
Edit: make triple sure that Watchpower etc are not running; you need to use the exit menu, not just close the app.

Hi @stuvo, download the latest firmware 72.70b from here. This is the latest patched firmware working as intended. 
1. Make sure you have closed all programs using the com port, i.e. WatchPower.
2. Ensure you are have selected the correct com port connected to your inverter.
3. Ensure you are updating the firmware with a serial port and not USB port.
You should then get the above screen and after about 20 seconds, the flashing process should start. It takes about 8 minutes to complete. 

Welcome Gabriel
 Send me your e-mail address in a personal message and I will send you a copy of Don's Axpert guide .

You can search the internet till you are blue in the face, or download the latest firmware version here from my Dropbox.

@stuvo. There is no such thing as a stupid question.
To link to a user's name: Type @ and a space, then start to type the users name. It might start off with a few names. Keep going until you see the name you want and then select the name.