Lux ac battery controller

chainreaction

some of you may be aware, an Australian company, Solcast, offer free solar irradiation information for any location in the world. You can set up a free account, input your solar pv details, direction they face (i'm told you can create 2, 3 solar arrays if you have them facing different directions - mine all point south), tilt on roof, size of array, size of inverter, age they have been installed, panel efficiency etc. You can then get forward predictions of solar generation (pictorial and excell (every 30 mins)) for tomorrow and also for next 3 days. Back in march I started tracking the mid (most likely) and low generation prediction from solcast against actual generation from my system and after a few tweaks, as I was guessing tilt and any loss of efficiency since they have been installed, the predictions generally matched the actual within 10-15%. ive got the confidence now to just use solcast to decide how much overnight charging I do based on the forward prediction. couple of screen shots below for tomorrow/next few days, based on this I wont be recharging the batteries overnight tonight and just allow solar to refill (most probably by around lunchtime), but very likely to fully charge them overnight tuesday for wednesday as predicted v low solar irradiance.
 url is https://solcast.com/

chainreaction

ah I was relaying what happens with my installation. As I added the lux system as an AC coupled system after the solar pv. My solar generation feeds into the electrical system between my old DB and the smart meter, so when we lose grid the solar system detects this and shuts down. Now with the lux system it has also detected loss of grid and switched onto the EPS. so the pv cannot generate onto the grid and my lux has its own circuits to feed, again isolated from the grid. within the circuits that are kept powered via the lux EPS, I have 2x250 solar panels with a micro inverter to allow them to directly feed into my garage circuit and reduce the burden on the batteries. I'm unsure about a hybrid system I would have thought they would also have some form of grid detection to shut off the solar feeding a dead grid system. 

i guess you could switch over the full house on detection of loss of grid, where does your solar pv system connect into your electrical system? 

we had earth rods fitted when we extended the house, so have a good grounding system via this.

newbuilder

chainreaction said:

ah I was relaying what happens with my installation. As I added the lux system as an AC coupled system after the solar pv. My solar generation feeds into the electrical system between my old DB and the smart meter, so when we lose grid the solar system detects this and shuts down. Now with the lux system it has also detected loss of grid and switched onto the EPS. so the pv cannot generate onto the grid and my lux has its own circuits to feed, again isolated from the grid. within the circuits that are kept powered via the lux EPS, I have 2x250 solar panels with a micro inverter to allow them to directly feed into my garage circuit and reduce the burden on the batteries. I'm unsure about a hybrid system I would have thought they would also have some form of grid detection to shut off the solar feeding a dead grid system. 

i guess you could switch over the full house on detection of loss of grid, where does your solar pv system connect into your electrical system? 

we had earth rods fitted when we extended the house, so have a good grounding system via this.

Mine comes in to the DB so I would bring the EPS to the same point and fit a manual switchover before sending the tail to the DB. 

chainreaction

newbuilder said:

Mine comes in to the DB so I would bring the EPS to the same point and fit a manual switchover before sending the tail to the DB. 

You'll need to be really careful where you put the switch. If you want to include a 5kw solar system into a potential EPS/Inverter circuit, ie providing quite a large generation into a small grid islanded system. Imagine if you had a powercut, batteries largely full and solar generating fairly low output, you then switch the EPS in, clouds clear and solar wants to produce 4-5kw. your inverter would not be able to cope because the solar provides far too much generation compared to the house and any battery charge load, I guess there is over frequency and over voltage protection which would operate on the inverter.  

newbuilder

chainreaction said:

newbuilder said:

Mine comes in to the DB so I would bring the EPS to the same point and fit a manual switchover before sending the tail to the DB. 

You'll need to be really careful where you put the switch. If you want to include a 5kw solar system into a potential EPS/Inverter circuit, ie providing quite a large generation into a small grid islanded system. Imagine if you had a powercut, batteries largely full and solar generating fairly low output, you then switch the EPS in, clouds clear and solar wants to produce 4-5kw. your inverter would not be able to cope because the solar provides far too much generation compared to the house and any battery charge load, I guess there is over frequency and over voltage protection which would operate on the inverter.  

Sorry I think I misunderstood. I would not operate the solar other than through the hybrid inverter. I would assume it would operate on a charge battery only or ignore the input of solar as there was no grid to even out the solar fluctuation. 

chainreaction

i dont know enough about how the hybrid inverter works in a grid island situation for what you want to use it for. the Luxpowertek website says these models have an off grid mode ie solar can be used to support grid island ......LXP Hybrid 3-6k and the LXP Hybrid 4-6k HB. so it may be possible. have a look at your manual to see how the off grid mode is used if you have it.

Mr_Adam

Hello. You all seem helpful so I hope you can help me!!

I had a Lux inverter and 5 x 2.4kwh of Aoboet batteries installed yesterday.

Today we exported 2.4kwh of electricity even though the batteries were never full.

The batteries DID charge, and occasionally when the sun came out charged quickly. But it was never out for long enough. And it kept pumping electricity either out into the grid, as well as also importing quite a bit even when we had spare battery capacity.

I haven't changed any discharge settings in the app. Any idea why I might be exporting so much?

Mr_Adam

This image shows my problem. In the column second from the end, you can see how much is being exported every 5 mins, despite my SoC being 42% only. 

Any ideas from anybody from this data?

Mr_Adam

sorry not learned to edit posts!

devondumpling1961

Can you post a picture of your "Input&Output Power" graph for the day (the one on the monitor tab of the luxpowerteck server webpage)?