Lux ac battery controller

ianatkin

EVandPV said:

ianatkin said:

Hello all

I have recently had an LuxPower 3.6kW hybrid inverter installed along PV and 7.2kWh of Aoeboet UHome batteries (three 2.4kWh units).  I know this thread relates to the AC coupled inverter but I hope the software is sufficiently similar that you can offer some advice for me please.

The reported battery SOC seems to be a bit random - just boiling the kettle can cause the SOC to drop by 10% at times and yet the battery will continue to charge from solar for hours after the SOC reaches 99%.  Could anyone confirm whether the BatCapacity of 129 in the configuration section sounds right for 7.2kWh (6.6kWh usable) please?

The Batcapacity field refers to the total ah of your battery stack. We also have a total of 7.2kwh although Pylontech batteries and each of the 3 modules is 50ah so our Batcapacity field shows 150.

That's interesting, assuming the batteries are functionally identical you'd think the same BatCapacity value would be used.

Can I change the BatCapacity from the inverter menu (I'm guessing you need an installer level login to do it from the web/app) and can you think of any reason why trying changing it to 150 would be a bad idea?

EVandPV

ianatkin said:

EVandPV said:

ianatkin said:

Hello all

I have recently had an LuxPower 3.6kW hybrid inverter installed along PV and 7.2kWh of Aoeboet UHome batteries (three 2.4kWh units).  I know this thread relates to the AC coupled inverter but I hope the software is sufficiently similar that you can offer some advice for me please.

The reported battery SOC seems to be a bit random - just boiling the kettle can cause the SOC to drop by 10% at times and yet the battery will continue to charge from solar for hours after the SOC reaches 99%.  Could anyone confirm whether the BatCapacity of 129 in the configuration section sounds right for 7.2kWh (6.6kWh usable) please?

The Batcapacity field refers to the total ah of your battery stack. We also have a total of 7.2kwh although Pylontech batteries and each of the 3 modules is 50ah so our Batcapacity field shows 150.

That's interesting, assuming the batteries are functionally identical you'd think the same BatCapacity value would be used.

Can I change the BatCapacity from the inverter menu (I'm guessing you need an installer level login to do it from the web/app) and can you think of any reason why trying changing it to 150 would be a bad idea?

Here's the instructions from the manual for battery settings (assuming it's the same for the hybrid inverter). Don't think there is any option for setting the ah, just type (li-ion) and brand.
The total installed ah should show on the inverter lcd.

ianatkin

EVandPV said:

Here's the instructions from the manual for battery settings (assuming it's the same for the hybrid inverter). Don't think there is any option for setting the ah, just type (li-ion) and brand.
The total installed ah should show on the inverter lcd.

Thanks for posting that and sorry for the slow reply.  The screen on the hybrid inverter is totally different (it's a small LCD matrix display) but your info gave me the confidence to go into the menu and have a look - the sequence of steps is the same and it turns out everything was already set correctly for the UHome batteries.

I'd like to know if anyone else can confirm it is normal for the %SOC with the UHome batteries to be highly non-linear?  I often find that boiling the kettle will take 5% off the SOC when I'd expect it to be <2% given the supposed 6.6kWh usable capacity.  I also find the SOC will rise to 99% when charging and they will keep charging at a high rate for at least another hour while at 99%.  I don't get the full 3.5kW discharge rate once I get below 20% either, it's more like 1.5-2.0kW as it gets down towards the 10% cutoff.

I'm sure all of these are normal but I haven't had the opportunity to do a full charge/discharge cycle at a time when I can monitor the total kWh charged/discharged without house loads interfering.

Solarchaser

Uhome from previous reports don't seem to respond linearly. And have dubious state of charge indication

billy_fixit

I'd agree with that analysis.
I have 4 x 2.4Kwh Uhome AOBET batteries and a Lux controller.
I find the LUX controller excellent (occasional web interface outages, but pretty good), but I'm not very happy with the batteries overall. The biggest problem is the hopeless SOC reporting and very poor linearity. I find they can be (say 80% full, then you take 100w out of them for a few minutes and they can drop to 70%. Then when the solar panels put a few 100w-minutes back in they can bounce back to 95%, all in the space of a few minutes. All this from a (nominal) ~10KwH battery bank.
It makes any meaningful monitoring throughout the day impossible and when they decide (rightly or wrongly) that they are flat (10% SOC) that's it for the day (unless you get a burst of sunshine, in which case they could leap back up to 40%.....and then back to 10% again).
I'm not convinced that I haven't got 1 duff battery, disturbing SOC reporting, but I haven't yet spent (a lot) of time trying to methodically diagnose this.
I like the idea of the LUX + batteries and they do work fairly well, subject to the poor SOC reporting, and I would like to add more, but you can't mix AOBET & other brands on the same LUX box and I don't really want to just add more AOBET batteries without understanding the behaviour I'm seeing first.

ianatkin

billy_fixit said:

I'd agree with that analysis.
I have 4 x 2.4Kwh Uhome AOBET batteries and a Lux controller.
I find the LUX controller excellent (occasional web interface outages, but pretty good), but I'm not very happy with the batteries overall. The biggest problem is the hopeless SOC reporting and very poor linearity. I find they can be (say 80% full, then you take 100w out of them for a few minutes and they can drop to 70%. Then when the solar panels put a few 100w-minutes back in they can bounce back to 95%, all in the space of a few minutes. All this from a (nominal) ~10KwH battery bank.
It makes any meaningful monitoring throughout the day impossible and when they decide (rightly or wrongly) that they are flat (10% SOC) that's it for the day (unless you get a burst of sunshine, in which case they could leap back up to 40%.....and then back to 10% again).
I'm not convinced that I haven't got 1 duff battery, disturbing SOC reporting, but I haven't yet spent (a lot) of time trying to methodically diagnose this.
I like the idea of the LUX + batteries and they do work fairly well, subject to the poor SOC reporting, and I would like to add more, but you can't mix AOBET & other brands on the same LUX box and I don't really want to just add more AOBET batteries without understanding the behaviour I'm seeing first.

I fully agree. I wasn't provided with the details for how to login to the batteries by the installer so I don't have any means of checking all three batteries are working properly, but equally I don't have enough information to be able to go back to the installers confidently and say there's an issue. 

I have been trying to record how many % battery I've been using versus PV generated to work out the optimum amount to top the batteries up overnight (I'm on Octopus Go Faster) but it's pretty pointless because the SOC is basically a random number generator. 

Also, according to the LuxPower web portal, in the month or so they've been installed the batteries have charged 177kWh and discharged 137kWh. If those figures are correct I'm only getting 77% efficiency which is much worse than I expected. The figures could be rubbish though, just like the SOC 🤷‍♂️

newbuilder

download the download the aoboet app and register, then scan or enter the barcodes. 

billy_fixit

Re: iantkin's comment above about charge in vs charge out averaging about 77%: Yes, I pretty much see the same number - ~75% - averaged over about 8 months for me now (Spring, Summer, early autumn,. Solar charging, mains charging, partial/full discharging. ie a pretty representative real world usage for 8 months)

 Initially this is what got me wondering about 1 of my 4 batteries being duff, but since, of course, I could never expect 100% efficiency, I'm beginning to think that it does indeed represent an overall efficiency of ~75% which is a bit disappointing.
This means that with a nominal 9.6KwH bank and a minimum cut-off SOC of 10% and assuming you charge them right up to 100% and an observed 75% efficiency then you can really only get about 6.5KwH out of your nominal 9.6KwH bank.

I too was never given any information of how to log into the batteries (at least 2 were really duff on installation and had to be replaced within a few days) and I did snoop around for information and I found the AOBOET manual & app and tried to use it, but at least some of my batteries simply will NOT present any SSID upon resetting with the white switch on the front for > 7s upon switch-on. I've managed to do 1, so I kinda know how to use the app, but I can't get other batteries to do the same.

Since 2 people now seem to be seeing ~75% efficiency it would be good to get a bit more data from others to see if that number seems to be common. Slightly disappointingly, I suspect it might be.

EVandPV

Going by the 'energy overview' graph on the web portal and the 'battery' field, I'm getting around 5.5kwh from a 7.2kwh bank of Pylontechs at 10% cut-off so 76% efficiency.
Must admit, I thought it was a bit more than that too.

So although the Aoboets seem to behave differently, the end efficiency seems the same as Pylontech.

ianatkin

The inverter datasheet says the battery charge/discharge efficiency is 94.5% and the battery datasheet says each 2.4kWh unit has 2.2kWh usable energy. 

I know they're a bit like how my 30kWh Leaf was claimed to be able to do 155 miles per charge (ha) but it seems to me like both the battery usable energy and inverter efficiency are quite a bit below where they are claimed to be. Quite disappointing tbh.