Solis Hybrid - charge battery using Night rate

SD_DRACULA

Yeah like @bullit_dodger said, check the inverter.

If you see four DC cables going into it then you have two strings.

Could try re-seating them to see if it helps in case one is loose but just turn off the whole system to be safe, and do it at night.

Also look back in time at your Solis cloud data, go back a few months and check the voltage/generation of the PV2 string, you might find it stopped at some point which means a loose connection somewhere.

Could also try getting onto Solis support and have them remotely check for alarms/issues.

HandsomeRover

Thanks for the replies lads..

I'll take a detailed look this evening and see what the story is.

Pretty sure I have the Solis 4G Single Phase Inverter, will confirm.

Sadly, the app/webpage hangs when I try scroll back in time to look at weekly data to see the PV1 & PV2 figures. These figures are not available in the monthly or yearly views. I tried exporting weekly data (the system was only installed in September 2020), but it just hangs..

I'll look at the inverter DC inputs to see if there are 2 or 4 cables, any poking I do will be with the power off and the inverter isolated, at night.

Is there any way to see individual panel DC contributions to fault find? I've downloaded the Installation Manual and couldn't see any way after a quick look through it. If they are on a string then I guess not anyway.

I'm not an electrician and have a healthy fear of electricity so I'll err on the side of caution 😉

HandsomeRover

Some photos of my setup. Apologies, I can't rotate them from my phone.

4 cables going in, one thing I noticed was the (+) terminal connectors seem reversed.. is that expected? These are the ones where the threads aren't fully closed.

I didn't attempt to disconnect/re-seat them, is that straight forward?

Is it possible a fuse is blown on one side?

If anything jumps out as a suspect I'd be glad to hear from you..

irishchris

https://www.boards.ie/discussion/comment/118885811#Comment_118885811

Two things from the pictures. First your positive MC4 connectors are barely tightened and should be further tightened to give better connection and seal.

Secondly your pylontech batteries are wired incorrectly

Unfortunately neither of these will probably help in any way with your issue but worth noting particularly the wiring of the batteries doesn't give me confidence in the installer.

HandsomeRover

Ah Jaysus!

Thanks for the info.. I can tighten the two positive terminals.. was surprised to see that to be honest.

What's the issue with the batteries - wired in parallel?

Jonathan

https://www.boards.ie/discussion/comment/118886146#Comment_118886146

The +/- wiring to/from the inverter are both from the same battery. This will result in uneven loads being drawn from the batteries. They should be wired like this.

HandsomeRover

Thanks for that..

I'm trying to visualise the schematic connections from the inverter to the battery.. in that there are only two.. right?

So I should be able to reconfigure my battery wiring as you've shown, without much risk of creating a problem.

I think I'll have to get a pro in to have a full inspection/reconfiguration/fault find and see if that improves things..

Sound lads...

Jonathan

https://www.boards.ie/discussion/comment/118886588#Comment_118886588

Yes. In that photo (which I robbed off google), the +/- to/from inverter are in the top right of photo.

Have a look at these two Will Prowse videos which explain the issue rather well:

https://www.youtube.com/watch?v=oXBT8lSC25M

https://www.youtube.com/watch?v=1U6E1bvjDYQ

irishchris

https://www.boards.ie/discussion/comment/118886588#Comment_118886588

Yep just make sure you power everything off at isolators before attempting to disconnect and tighten those mc4 connectors.

Reconnecting the battery cables correctly as above should be simple task and again just power battery and inverter down before doing it and not whilst under load.

Poor from installer in fairness but easily fixed 👍

HandsomeRover

https://www.boards.ie/discussion/comment/118886692#Comment_118886692

So...

I powered everything down and isolated everything to re-configured the battery connections..

Is there a sequential sequence to restart everything?

My issue now is the Inverter doesn't power up when restoring everything as was..

No trips on the breaker

Edit: Sorted..

The sequence is:

First, Grid Power ON

Then Batteries ON (for me I needed to hit SW on both batteries)

Then PV array ON

And back in business. I fiddled with the DC2 connections and tried to tighten the threads on both (+) connectors but didnt get very far. Might get a few quotes to look/fix.

Thanks again for the advice..

Nuphor

I don't see a "Self Use" option on my RHI-3.6K-48ES, installed about 2 years ago. I presume it's because of out of date firmware (surprising, it was only installed 2 years ago). Reached out to support to see what my options are.

HandsomeRover

https://www.boards.ie/discussion/comment/118885811#Comment_118885811

I took a closer look at the setup there earlier.

The working string of 8 panels (DC1 on the inverter, PV1 on the Solis app/webpage) was reading 273V at the automatic switch. Cloudy and showery all day.

The other string of 8 panels (DC2 or PV2) was reading just 1V at the automatic switch. My problem is on the roof.

Ideally I'd like to halve the problem, ie figure out which string of 8 has the problem. All 16 panels are in a single line.

Any suggestions on how to do this easily and safely? I have a clamp meter but its AC rated, but it did accurately read the DC current to a car battery from a charger, so not sure if this will help me.

If I release the clamps between panels is it easy to manoevre them out of the way to inspect the connections?

Any inspection would be done with inverter off, PV isolated and after sundown.

bullit_dodger

Have you optimizers on the panels? If not you should be able to do it easily enough, with the help of a 2nd person.

Just shade 1/2 a panel or so with a long brush or something and the power should drop off (or not) on that string. If it doesn't then you know it's the other string.

HandsomeRover

Lovely simple solution!

I don't know if I have optimisers - I'm only getting to grips with what's up there as I'm not long in the place and the previous owner had this installed.

Ideally I'd like to get a camera under a few of the panels and see the model/spec etc.

I'm assuming the circuit diagram is something like this...

I'd be grateful if you point out any discrepancies you see..

reklamos

https://www.boards.ie/discussion/comment/118891236#Comment_118891236

The battery power up sequence is not correct. As you have 2 of them and they are interconnected, the powerup is controled from master battery(the top one in your case). Turn both batteries on with the switch rocker switch than on the master press and hold red SW button. You will see the lights on the master will light up and then the same will happen on slave batteries. When all of them do that, only then you release the red button.

reklamos

https://www.boards.ie/discussion/comment/118928178#Comment_118928178

I think potentialy there could be couple issues: 1. bad connection, bad mppt string, bad pannel(same as bad connection).

When you have sun and also with battery charged(otherwise your inverter won't start). Have one string connected to one MPPT and then move it to other. Do the same with other string. This will show if it is on onverter side or not. POWER OFF your system when working on it.

If inverter is good you will also identify which PV string is bad and then can trace cables. It could be that the connection is bad just where the cables leave the panels to house. It could be that there is a bad connection between the panels but you will need to get on the roof to check that. Before getting on the roof just get a good torch, shine under panels and visualy inspect you may see it right away. Since your MC4 connecter was not seeting properly it could be also the same issue on the roof.

BTW: your inverter is G4 same as mine

HandsomeRover

Thanks very much for the advice on the battery power up method.

It's raining at the minute so probably won't get an opportunity to switch inputs today but I'll give it a go at some stage.

I'll also try the shading of a panel to try identify the problem string (it may not ultimately be the string) but at least if the inverter is ok then I'm honing in on it.

Much appreciated...

I'll keep you updated.

HandsomeRover

By the way..

When I'm on the roof fiddling with connections with my multimeter with everything OFF, the panels will be generating in my hand.. I'm a path to ground.. how do you avoid issues? Cover them up?

HandsomeRover

I draped a bath towel over panel #9 of 16 (so the second string) and there was no change in the generated figure over 15 minutes.

Moved the towel to panel #6 (the first string) and the figure dropped by half. Removed the towel and the figures restored.

At least now I know what string is what and where to start looking if I get up on the roof.

con747

https://www.boards.ie/discussion/comment/118933113#Comment_118933113

Not sure if has any relevance to your problem but after a recent install I noticed 1 string wasn't working and the installer came and said there was a problem with a faulty fireman switch causing it. Now on the day I was juggling 2 companies doing different work trying to keep an eye on what they were doing so not exactly sure where he found the issue. I do know it was either in the attic or at the system which I have at ground level, so he didn't go near the panels on the roof.

HandsomeRover

Interesting. I'll take a closer look at the fireman's switch.

I might also try disconnect the them at the input to the fireman's switch and measure the voltage again, see if the readings still hold. Or even swap them and see do they flip in the software.

Thanks for the steer.

up_north

Hi all. I hope you don’t mind someone from the UK posting here. This forum was top of my Google search results!

i’ve read through this post and although it hurts my head, I THINK I now have the answer to my query but would appreciate some confirmation.

Installer has recommended 3.8kw Solis RHI inverter with 5kw Puredrive battery.

I am on an electricity tariff which gives me much cheaper electricity between 8.30pm and 1.30am. From what I’ve read above, I think I can set the battery to charge during those hours. But I take it that charge time is only with regards to the grid charge time, so outside of those hours it will still charge from solar if available? I also don’t want it to discharge during those 5 hours.

Thanks.

bullit_dodger

https://www.boards.ie/discussion/comment/119101820#Comment_119101820

Posting from Blighty - all good!

Most inverters you can specify the charge and discharge periods, sometimes even telling it to have "cut off" figures. such as

"Discharge to 20% and then stop"

So to answer your question.....yeah, you can charge your battery (and not allow it to discharge) between 8:30pm and 1:30am no problem.

Aside: What is the spec you've been recommended. Battery sounds right at 5Kwhr for most people, but normally people would need 5kw or even 6Kw inverters unless you have a really small house load?

up_north

Thanks for your reply bullit_dodger

House is quite small. We use no more than 10kw/h per day (excluding car charging) and most of that is in the evening. The quoted system is for 10x4kw panels and 3.6 inverter. In UK, if the inverter is higher than 4kw (I think) you have to apply for special permission from the electricity supplier. So an inverter less than 4kw is fairly standard. My gut feeling is to opt for a bigger battery though.

Ian

reklamos

https://www.boards.ie/discussion/comment/119101820#Comment_119101820

On Solis if you set schedule to charge it for 5 hours, this is waht it will try do do and will not discharge. Yuo can also have multiple schedules set to that it charges for 5 hours than holds for another 5 and only discharges during the day.

bullit_dodger

https://www.boards.ie/discussion/comment/119102280#Comment_119102280

In Ireland the actual limit is 6Kw for the inverter, but you have to submit a form called NC6. In the UK you have a blanket "prior approval" for inverters up to 3.68Kw. I would however push your panels up to 4.4Kwp if you can, just 1 more panel (£200 or so). The inverter can handle 20% over no problem (in fact it's often recommended). The reason is that on the marginal days of March or Sept/Oct, that extra panel (10% in production) will make a difference.

up_north

https://www.boards.ie/discussion/comment/119102703#Comment_119102703

Thanks for that. Sounds like I’ll have no problem there.

up_north

https://www.boards.ie/discussion/comment/119103064#Comment_119103064

The installer has suggested 4kw panels so a bit above the inverter output.

I have asked him to also quote for a Solar Edge system to help minimise loss through shading. About 30% of the roof is in shade from neighbouring house till 9.30. The panels will be laid out as two rows of five and the shading will be right to left which means the two strings of 5 will need to be wired as L shapes but the panel in the short leg of the L won’t be in shade but would be affected by the other four in that string, hence who I want to consider Solar Edge.

yankinlk

https://www.boards.ie/discussion/comment/119103622#Comment_119103622

In shade until 930am? Don't bother. If its 930pm then yeah.

bullit_dodger

https://www.boards.ie/discussion/comment/119103861#Comment_119103861

Don't forget, it also depends on what time of the year. 9:30am when the sun comes up at 8am is nothing, but if the sun comes up at 6am, that potentially could be a fair bit of generation going astray. But in general, yankinlk is spot on. Weight carefully installing optimizer at €50 a pop on panels that you might (might) get an extra hour or two generation on a few sunny mornings a year.

4.4kwp on a 3.68Kw inverter is fine. Splash out on the extra panel for £200 and get the 11 panels

Trust me! (or the next person to reply and tell you the same :-)