Lux ac battery controller

petelancaster1988

Hi all,

New to the forum, just joined up as I have a problem which I am now at the point of tearing my hair out over. Apologies in advance for the slightly long winded explanation that is to come, but hopefully there might be some ideas on here that I have not yet tried.

I have a Lux 3.6kW Hybrid Inverter and 2 x Uhome 2400 DC coupled batteries for a total of 4.8kW of storage. I have acquired an additional battery, exactly the same as the previous two, to be able to increase storage capacity up to 7.2kW.

Upon correctly connecting up the new battery to the existing two, ensuring all cabling, comms cables and dip switches are correct, then powering everything up, the master battery and the new battery throw on the red fault light.

I can connect the new battery up to the inverter on its own and it works perfectly well, happily charging and discharging as needed.

In my Lux monitoring app, the two batteries that I have had working for a good while now show as having a capacity of 43Ah each, for a total of 86Ah. 2400W divided by 43Ah gives a voltage of around 55V, so I know that this Ah figure is correct for the battery size.

When I plug the new battery into the inverter on its own, it shows as a 50Ah capacity in the app, still with a voltage of around 55V. I have checked this voltage with a multi meter and can confirm the voltage is showing as somewhere near 55V. but 50Ah multipled by 55V gives somewhere like 2700W, which cannot be correct, as this battery is the same in all specifications to the existing two.

The error that gets thrown up by the inverter when all three batteries are connected together appears to relate to it not liking mismatched capacities, which seems to be because two of the batteries are declaring themselves to the inverter as 43Ah and the newest is declaring 50Ah.

I'm not sure where to go from here. My installer also seems to be a bit lost with it, and there doesn't seem to be any easy way of changing the 50Ah signal to 43Ah in either the battery itself or in the inverter, to try and get all three working together.

If anyone has any bright ideas about what might be going on, I'd be really, really grateful!!

Many thanks,
Pete

Solarchaser

That's a bit of a weird one right enough.

Uhome are a bit of an anomaly right enough.
I can't see the inverter being the issue as I have 3 pylontech 2400 and one 3500 connected together on an inverter with no issues.

Could you try connecting just the batteries together with no comms leads and no link to the inverter for an hour and see if they balance themselves out?

petelancaster1988

Thanks for the suggestion. I did have the three batteries connected together and not connected to the inverter over the weekend, to try an balance them, but with no joy.

I have measured all three batteries with a multi meter and they each show a consistent voltage of around 53V. Already pretty balanced, it seems.

So I don't think the issue is with the batteries themselves or the electricity inside them. I think it has to be a communication issue on the third battery, its telling the inverter something different from the other two.

petelancaster1988

I'm just trying the balancing thing again but without the comms cables in, and to be fair, this time there is some charging and discharging going on between the batteries....

Fingers crossed!

propnut

I think the nominal voltage is 48v so 2400/48 = 50. Check in the inverter settings that the battery is set to type 7 = Uhome. Then it will read 43ah per pack. If however you have it set to the default which is 2 (pylontech) then it will read 50ah per pack. I added a new battery to my setup with no issues whatsoever. Did you set the dial on the primary pack to tye correct number and set the dip switches correctly on the slaves ???

petelancaster1988

Thanks for the advice. In my inverter, the battery settings are not listed as numbers, but rather by the names of the batteries.
The options I have are: AOBO, LUX, GSL1, MSUN, Enopt, PYLON, RESVD, STD, OKSOL, BITEK, MuRat, WeCo, NARA, BYD, MERIT, TLM, Steal, DYNES.

My understanding is that AOBO is correct...? I too thought it must be a setting somewhere, as why would the inverter read 43Ah for a couple of the batteries, and 50Ah for the other. If you think that it should be one of the other battery types, please let me know and I will try that on the new battery.

I have left them to balance overnight, and am now charging all of them individually back to full, to make sure all of the SoC readings are correct.

propnut

Ok I am not familiar with the Hybrid as I have the ACS which had the battery types encoded as a numerical value. I just know that when I set mine as AOBOET they show up as 43ah but when set as Pylontech they show as the correct 50ah. Note I am not suggesting you change just giving you my observations.

Did you check your dial and switch settings. If not consult the manual as if not set correctly you will get analogous behaviour.

petelancaster1988

Yes, all dial and switch settings were correct. Given your perfectly logical explanation that the nominal voltage should be used (48V) and therefore 50Ah would appear to be the correct Ah rating, I'm now wondering if I should set my existing two batteries to AOBO, which on my system gives a 50Ah readout.

That in theory would then have the three batteries at a total of 150Ah and there shouldn't be any issues with mismatched capacities...

propnut

Just one thing to note on the dial and dip switch settings. If you have three batteries then the primary battery need to be set to 3. Then battery 2 is set to 1 and 3 to 2. 

Then SW2 on the primary should have 1 & 3 on. The 2nd battery they should all be off and then on the 3rd battery 1 should be on.

Oh and by the way you will NEVER get 7.2KW's. If you read the documentation it clearly states that actual useable is 2.2KW per battery. But 2.2KW is 92% whereas the allowable DoD is 90% so actually if you do the math 90% of 2400 = 2160W so in reality 3 x Uhomes is only going to deliver 6.48KW's. Marketing is just professional lying.

petelancaster1988

Yes, the SW3 and SW2 dip settings are exactly as you describe, believe me I've cross checked them a thousands times with the manual!

And yes, fully understand regarding only 90% usable capacity. However the battery itself does still hold 2.4kw, even if only 2.16kW is usable in each one. So the Ah figure should still correspond to the whole 2.4kW amount.

In any case, I've managed to get my installer to get in touch with Lux directly and they are now looking into it, suggesting that the latest battery may need some sort of hard reset, apparently...

Will keep you all posted!