Scorp007

I have just bought another BMS from the link I mentioned. Pay today and got my BMS the next day via courier. +1 from me.

I agree 100%. My own temperature vs power used between a normal element and the PTC heating a 25L closed container did only show a 5% gain for the PTC when using the AC portion of a PTC. This in itself does not warrant the added cost. The fact that the PTC should never burn out is a plus but one can buy 6 or more normal elements. The 5% difference can just as well be the uncontrolled environment in which my test was conducted.

Just to clear up the accuracy of prepaid meters. The international standard is all meters used for charging consumers is within 1% error. The error allowed is much smaller for industrial consumers. There are companies coming at quite a cost that are using calibrated equipment and their reports will stand good in a court of law when there is a dispute. As far as the previous comment. If after/before the test you have all equipment off for about 3 min you get quite a good reading and this allows for the data to be send to the master meter from/to the CUI. Just ensure that a pure resistive load like a kettle or heater without a fan is used for measuring with a clamp meter or better still to use another power meter with known high accuracy. Some installers do have such meters they use. Kill-a-watt comes to lite but are of a unknown accuracy and can differ from one meter to the next. No standards are enforced on them as per prepaid power meters.

2 points now that we have values. The power used under consumption would include about 50-80W that the inverter is using for self power. With loads as low as you have and fully charged battery the panels cannot produce more than the loads switched on. A instant test if you look on the screen and not the once every 5min reading would be to switch on a kettle and say the microwave. You will the see a big jump in the power produced by the panels. You will notice on all the days you showed the power produced by the panels exceed the power you used for loads. Thus with higher loads during the day time you will see the increase in daily production. One of the slides show the battery was deeply discharged and that day you daily production was much higher than what you used for loads.

The only thing I can think of is your old meter did not measure the actual power you used. If you had a inverter that could export or turn in reverse one would have thought this was more likely the reason for your post paid low reading. One other thing is to make sure the prepaid you have now is yours and not the guy next door if they were installed at the same time. I recently heard of a guy in a 3 unit complex each with their own turn meter and one of the 3 had a power used per month of only 5 units. His meter turned a lot slower even if he had the normal appliances. The meter got changed and his bill went up big time.

Thanks for the info. I was wondering if chicks have the brains to stay close to the heat lamp? 😀

Just out of interest. How many heat lamps are you having and what Watts is consumed by each lamp? I know nothing about heating as used in chicken farming 😀

How many Watts are being supplied by the panels, battery and grid and what is the consumption reading?

Luckily we know not to feed DC to the AC thermostat and heating via panels MUST be done via a relay coil connected to the thermostat or using a PV to geyser controller. One point I would like to raise which is a major plus that I have not seen raised. When using a heat pump one can always tap the hot water coming out of the heat pump before it enters the geyser and use it to a tap that is just partially open. This off take can be at over 45 degrees even if the water in the geyser is say at 25 degrees. I tested this 13yrs ago when installing my heat pump but it has fallen by the way side as a plus point. I retested it recently when I needed hot water to do dishes.

10A in order to allow short term surges.

I take it you want your inverter to work like this in the pic. Today I had 2 elec stove plates on for over 6hrs. Grid use is in brown. The battery was still charging from PV and the battery was kept at a certain minimum SOC. PV was low after about 14h00 due to cloud. Grid consumption in brown. Today was my highest daily consumption since installing the Deye. Perhaps some settings need to be changed on your side.

Is this the way off grid inverters are designed?

Just to add a point. Even if the reading(calibration) is out it will be the same for all cells. Rather get the balancing sorted out as @WannabeSolarSparky indicated in his post. The finer detail like calibration can be done later. Even calibrating at 3.35V could be out by the time it reads 3.65V. My experience with a JK.

This remains an interesting point. As you indicated you can mask the problem until a new cell is bought. Now I have been one that like the balancing from a low level. Yes we know most clever people would say only start balancing when cells start shooting the lights out at around 3.35-3.45V. My own observation has been the weak cell as pointed out will remain weak. The thing is if you start balancing say at 3.1V with an active balancer there is a good chance that 15min after using the high load this cell will have been charged during balancing. This better prepares this cell to at least provide power during the next high load before it drpos again. If the balancing starts only at 3.4V+ this weak cell will drop instantly and trigger the under voltage again. Such a weak cell can have a delta of around 200mV but will balance to a lower level like 5-10mV until loaded again. We must also take a clue from those BMSes that do a permanent active balancing from any level and surely although not ideal the designers did think it's a good way. For the above reason I prefer the active balancer vs the passive. Just my own view and could be flawed.

Normal convention it will be as explained. We do however deal with the MPPT which will strive to find the best spot for voltage and current to yield the highest PV power.

When you don't have enough PV it will not be a time to try and save by not using a lot of grid. Allow the grid to also charge so that you have ample battery power to help during the night.

Can you see on the display that it actually does charge the battery from PV? If it does then it seems it is only the DC to AC output that is at fault. If the battery is below the timer setting which is active does it also not use grid to produce a AC on the output?

Here are some members myself included that have been using the Epever MPPT solar controller with full lithium setting to charge batteries directly. They do have models that support up to 48V systems. I do however find the maximum PV input generally on the low side from a maximum voltage point as well as much lower in output than what we see on inverters. You can if 450W panels go to 22. The way of connecting will be like 2 strings of 5 in series and 2 in parallel. Then the 2nd MPPT is 6 in series and a 2nd string of 6 in parallel. This bring you to the 10.4kW maximum panels. You can also go 9 in series per MPPT but that is only 18 panels for 9kW of panels below the maximum allowed.

I presume this happens when you don't have the timer active so that grid can be used when the battery drops to this low level. I make sure I have a timer switched on when using my kitchen equipment. As these high draw items can cause this if the battery is not in 100% shape. The drop should not happen even if your comms is not working and the inverter uses voltage based. You can however just do a check by selecting voltage for charging even if just when you switch on the kettle with timer active. I have a 51.8V level with timer on during the 17h to 21h period to prevent battery to be discharged real fast. Check on the screen if grid use does increase when the kettle is on.

Can one blame the tree causing the more north to only start working from 09h00? The same reduction would cause a say east string with a tree shadow - not so? So many variables to consider that makes a huge difference between installations that can mostly if not at all times explain the reasons why yields differ big time.

If one has enough storage or load during the day the north still gives a much higher yield as you suggested. 😀

It means the current to each MPPT is high enough that you can have 2 parallel strings wired to the MPPT instead of using an external combiner box. You will then only use the combiner box to house the fuse, surge unit and isolator without paralleling. As you indicate. East and West then into the same MPPT. This can leave 2 x North string into the 2nd MPPT

This seems like a great addition the the range of inverters we can choose from. Impressive spec with 2 x MPPTs for 4 PV strings. Solar Warehouse SALuxPower 12kW Single Phase Eco Hybrid Inverter (SNA12000)...LuxPower 12kW Single Phase Eco Hybrid Inverter (SNA12000) (Pre-Order) PRE-ORDER NOW ETA 10/05/2025 Product Features Eco Hybrid Technology Energy Management System (EMS) Remote Monitoring and Contro...

Thankks for sharing a great link to cabinets.

This is a very important point as it caught me out as well as I thought if zero export to CT is ticked it won't sell solar.