ascheff

Perhaps try Setting 01 as SUb? Keep setting 12 low (default of 46 V is fine).
I would think that you would want operation logic (setting 10) to be online mode. In Auto operation logic, it will switch to bypass if it thinks that the AC-in frequency is unstable. Does the utility frequency seem stable?

Hi
ok. cool maybe @Coulomb can help or someone. lol 🙂   
 
watchpowerv1.14

The guy at Sinetech who I discussed my setup with after running into issues said they shouldn't be equalized 

If you don't have a PYL setting, then no, it does no good.
But you have a removable display on the 24 V King, right? That's what does all the hard work with the BMS protocol. I thought for a while that no 24 V model would offer any sort of BMS interaction at all. But to my surprise, it looks like you get PYL, LIB, and LIC protocols with e.g. removable display version 02.61. Frustratingly, with 02.62, you get none. I have no idea whether the 24 V Pylontech support is finished and working, or if they wanted to do it but decided it was too hard.
So if you're feeling adventurous, try reflashing your removable display to 02.61 and try it out.
What versions are you running now, as a point of interest?

Upon re-reading, you get one. But that one is PYL (Pylontech protocol).
So if you can get it to work, it appears that Voltronic Power intend to continue to support it in future firmware updates.
Of course, it would be nice if they actually said so somewhere, like on a web page.

Ah. In that case, I no longer recommend trying later firmware. When reading 02.xx display firmware, I see testing for 48V, (parts of the firmware code behave differently if 48V is not found) so I assumed that 24V models would use the same firmware. If yours is a fairly recent model (what is the manufacturing date on the small sticker?), then it would appear that 24V support is not production ready yet.
It would not be so much of a risk if you could revert to 01.12, or even any other 01.xx display firmware, but this is not possible as far as I know.
Firmware availability has been very low since the appearance of the clones in 2015. (Since the clone wars?) We rely on obscure sites like one in Czechoslovakia and owners that need updates for various reasons (bug fixes, paralleling with older versions) who share the update files. Possibly because they are less popular, 24V firmwares seem much harder to find. 

For you, I now suggest neither. But for general use and for which one to patch, or whether to wait longer, I'm still deciding.

If you happen to know someone with a later firmware version removable display, you could perhaps borrow the whole removable display. That way, there is a clear path back to original specifications 😃
Since the recommended charge current is 55 A, I would increase that to 50 A, in line with objective 3.
Since your battery will be 8S and mine is 16S, you could do worse than using half my voltage settings. Mine were carefully chosen by my colleague Weber, who teaches electricians about solar batteries. Mine are 55.2 and 53.7, so you should consider 27.6 V and 26.9 V (nearest 0.1V rounded up).
I would not want to go near that voltage (I never let mine go below 51.0 V, equivalent to 25.5 V). But you don't want to go too high, because if the interaction with the back-to-grid voltage (see FAQ #2 if interested in why). So I'd recommend 24.5 V. The latter will mean you can't go below 25.5 V effective for setting 12, back to grid. That's the value that I use. Setting 12 is another important setting, in some ways, the most important. It's what saves the battery from excessive discharge, which is the #1 killer of LFP cells and therefore batteries.
Unfortunately, it means that you need to exercise discipline when there is a long load shed /  utility outage. At least with these settings, you'll get a low battery warning at 25.5 V, and you should use that to immediately reduce loads, and preferably completely shut down the inverter. So leave the alarm beeper on.

Thanks for that. So it really comes down to what the typical conditions are and how long I want the batteries to last. So taking Coulomb's calculation, for the typical 4 hour loadshedding at my current average load of 160w: 160 x 4 = 640Wh., which is an 11% DOD. This would be "safe".
Less frequently, but not rare would be a cable fault, which takes perhaps 8 hours to fix, which is: 160 x 8 = 1280Wh, which is 22% DOD, which is still okay?
Rare, but not unheard of would be when a transformer explodes, and it may take 24 hours to get back online: 160 x 24 =  3840Wh, which is 66% discharge, and would be bad for the battery. Here ideally I should then switch to my backup generator during the day and/or lower the load to the absolute minimum.
At the "good number" of 50%, I would get 2875Wh to use, which is 18 hours runtime.
 
Am I on the right track with my understanding and calculations?

Assuming an average load of 160 W, 28 hours of runtime is about 4500 Wh. Your battery is rated at about 24 x 240 ~= 5750 Wh. So that test was a bit brutal, a nearly 80% discharge. All on its own, that test probably took a few percent of life from the battery.
I'm afraid that doesn't sound good for this battery.
ALL Axperts running non-patched firmware have the premature float bugs, sadly. The manufacturer simply refuses to acknowledge it.
Unfortunately, lead acid batteries don't like deep discharges. My guess is that over about a year or so, the under-charging has led to a lower and lower state of charge, which has killed the battery.
Those figures are good for 25°C. Does the battery get hot in summer where you are located? If so, those voltages should be reduced in summer.
Both of these are far too low if you routinely use that setting to stop discharging. It's meant to be a last resort thing; you are supposed to use switching to utility to stop discharging the battery way before it gets to this low of a voltage. I suspect you've had a lot of load shedding lately, so the inverter doesn't get the option to switch back to utility. So this setting should be up around 24.8 V (12.4 V per 12 V module) for reasonable battery life. Get the lead acid experts to pick a better number than that; I'm no lead acid expert.
This facility, or perhaps the equalisation facility, might be able to be used to work around the premature float bugs.
Leaving this at say 2d might be a reasonable way to fight the premature float bug. The problem is that with sealed lead acid, you have to be so careful not to over-charge as well as not to under-charge. So finding the right settings for your climate etc could be challenging.
If it's possible to set the equalisation voltage to less than the bulk/absorb voltage, that would be ideal. Keep the equalisation at 28.7 V (just under the gassing voltage, lower in summer) so that when the battery spends a lot of time in equalisation, it's not gassing off its very limited supply of water.
Wow, that's an unusual value for a King, in my very limited experience.
I suspect that this is the display firmware; I only know 02.00.
This is zero because you have no solar panels.
Lead acid batteries can recover from some situations, but unfortunately chronic undercharging isn't one of them.
This is the "working range" of the battery.
That very rapid drop in voltage indicates that the battery is very close to fully discharged. It should never be allowed to get into this range. That's why I suggest setting the low DC cutoff voltage to about 24.8 V, before it's really started this dive.
The beeping at 1.0 V above cutoff voltage (2.0 V for 48 V models) is an undocumented feature of all Axperts (as far as I know).
That's slightly disappointing accuracy. At least it's stopping the discharge a little early as a result.
So with your extremely modest loads (are they still modest, or has it been creeping up?) the battery is springing back by 4.2 V (an average of 1.2 V per 12 V module). That means that the battery has a very high internal resistance, which means it's really in bad shape, as well as very low in charge.
At least a big chunk of it seems to be inverter / settings related, as noted above. The battery looks decent to me, but get opinions from battery experts. You've paid some school fees with this first battery; many users do. I'd say get another battery (consider a lithium battery with a battery management system built in, if that's within budget), and make changes as noted above. Remember that a 12 V battery module should rarely if ever be seen at actual 12.0 volts.

Hi AScheff,
I am still learning about Axpert and batteries, but in my my opinion if you act quickly, there is a chance you can rescue the batteries by charging with a good external battery charger. One that can supply a high charging current, which may be able to correct any sulphation on the battery plates. As your batteries are sealed just have to be careful not to overcharge and lose electrolyte through gassing, as the batteries cannot be topped up.
How to charge the batteries:
1. Take them to a battery expert with charging equipment.
2. Buy a good charger
Hawkins are a good local make. These are manual chargers, use with care. They have a sticker 'do not use on sealed batteries'
Ctek make high quality smart chargers, quite pricey,  but quality chargers.
Midas sell a PDS008 charger for less than R1000, highly recommended by the 4x4 community for rescuing abused batteries! I used one of these yesterday and was quite impressed.
Both Ctek and PDS008 are so called smart chargers, they have many phases of charging which do various things to the battery, compared to the manual chargers which just use a brute force charge. Both are good, a charge is a charge!
If you buy a charger, disconnect your batteries, connect the charger and charge each battery overnight, one at a time.
Reconnect the batteries and hold thumbs, hope that the charger has paid for itself.
Let me know what happens, I would be interested in the outcome!
Omnipower are good batteries. Sealed for low maintenance, but probably can be opened to check water level. Of course this will invalidate the warranty.
If you have a good supplier contact, might be worth asking them for advice.
Good luck!
Solo
 
 
 
 
 
 
 
 
 
 
 
 
 
 

No, with battery modules in series, you double the voltage, but not the amp·hour capacity. You can never double both no matter how you connect them. Conservation of energy and all that.
So with two nominally 12 V 240 Ah modules in series, you now have a nominally 24 V 240 Ah battery. So you have double the energy (Wh), as you'd expect from doubling the number of modules.
A lead acid cell is nominally 2.0 volts. It's a matter of electrochemistry. So each 12 V module has 6 cells, and your two module battery has 12 cells. They are all in series, so for the purposes of the above calculations, the number of cells is indeed 12. (If you had strings in parallel, then the extra strings would not count.)
So using your figure of 33°C in summer, that's 8°C more than 25°C, so the bulk/absorb voltage per module should change from 14.4 V to 14.4 - (5/1000 x 8 x 6) =  14.16. For your total battery, this would double to 28.8 V → 28.32 V; use 28.3 V.
[ Edit: 14.4 V per 12 V module (2.40 V per cell) happens to be the gassing voltage. So in summer, your battery will start gassing at 28.3 V. So make sure that in summer, the equalisation voltage is no higher than 28.3 V. It can go back to 28.8 V in winter. ]
That's the thing with lead acid; they can only take a handful of really deep (near 100%) discharges.
I would not recommend attempting to update firmware from such a strange original version number. Plus, there isn't anything that would make a material difference to this situation.
 
They sure hurt.
Ah. I meant that the brand looks decent, and another poster has reinforced this.
Ah. I'm using the strict technical terminology; whatever collection of cells and modules you have, that's your battery. We're used to looking at a brick with terminals and 12 V on the side as a battery, and it is, but when you combine these to make a bigger thing, it gets confusing.
So throughout I've been referring to one brick as a battery module; you have two battery modules making up one battery. When I said you need a new battery, that means two new modules if you use the same parts. But you could have replaced it with say 8 Trojan modules, each about 105 Ah and nominally 6 V, connected four in series and two such strings in parallel. All that would still be one battery, but 8 battery modules.
I don't see the value in that. It's always a lot of finger pointing.

If you want to get really technical, they can take 1 (ONE!) full discharge. On the next iteration you have 99%, then 98%... after 20 full discharge cycles you have maybe 80% of the original left, and if you continue to discharge the battery until it is dead every time, then after 70 cycles you have half the original capacity left, and so forth. That's simple math if I assume the battery loses 1% on each complete discharge... which is probably not a bad estimate for a UPS-type battery.
In my experience, car batteries are even worse than that. Do that 20 times and that battery is toast...
There isn't really such a thing. The application determines what is considered a good value. In your typical UPS setup in a country where there aren't that many outages, a complete discharge is not considered a bad thing. Age will kill the battery long before it dies of hard work.
For a house I've seen people spec their banks anything from 50% DoD to 20%DoD to make them last, but even that seems like an exercise in futility, because generally the DoD vs cycle-life chart is fairly linear, by which I mean that if you discharge it only half as deep it only lasts twice as long. This is true at least for the middle of the "chart". So you can make the batteries last twice as long by only using half their capacity... but in the end your price per kWh stored is going to be very similar.
With all that said, most people will tell you that 50% is a good number.
And they do go faster if you discharge deeper than 80%. As I said, the linear part is only really sort-of in the middle 🙂
 

Definitely.
Yes.
As you say, it would be best for battery life to stop at 50% discharge. But if you have a business that depends on the electricity flowing, it may well be best to take the slight hit on battery life, rather than lose stock or whatever the costs are of the electricity not flowing. It all depends on your circumstances. And of course, the power may not come back when advertised, so at the end you are continually sweating the choice: do I hang on a bit longer, or quit now?
I've heard it claimed that this ability to take the very rare three times deeper than usual discharge is a feature of lead acid batteries, that for example no lithium chemistry can match. I'm not sure that I agree, but it's something you have that you may as well take advantage of, as long as it really is very rarely.

At a low 160W your calculations look about right, but do remember to add the self-consumption of the inverter itself, which for that particular model is around 50W if I recall, so you probably need to work it out at around 200W.
I would not say that a once-in-a-lifetime transformer explosion that results in a 70% DoD is necessarily "bad". As Coulomb just said: