Solar for Beginners [ask your questions here]

You only need optimisers if some or the panels are shaded.. if they panels facing a different direction are or a separate string you won't need optimisers.. if it were one string you would

Battery priority mode.

I have had a few issues with “Low battery voltage” warning lately.I set the inverter to battery priority mode last night,and it charged up within a few hours to 100%.My question is how long do I leave it on battery priority before I set it back to self consume mode.

Thanks for helping as the manual is not much help

And even at that, "needing" optimizers is a big word. They add significantly to the cost of the setup, they have a relatively high chance of failure and they at best only have minimal extra output / revenue. I wouldn't bother with them, unless you have no problem replacing them yourself if / when they break.

What type of inverter do you have?

I have a solis... And keep mine in self-use? Mode all the time... I only set the charging schedule to run in darker months... Oct/nov to march.

Schedule should match your night rate if you have one so it's cheaper. As long as battery is charging it won't feed the house load... So I stop charging 5 minutes before day rate kicks in. I start at 11pm... On a low amp so it takes all night to fill.

If you have an ev rate at say 4am for 2 hours... You could set it to fill during that cheap window. Then set another charge window at 0amp untill day rate starts.

Just with a query about Optimisers and reliability / performance. I am speccing out a possible system - the south facing roof of our terraced home has a dormer window and would likely lead to shade on the panels that would be installed on each side of it (in the morning and in the evening). My understanding is that optimisers would benefit the overall performance by not lowering everything to the 'lowest performing' panel at those times.

Are the oprimisers likely to create more of a maintenance headache than provide performance increase?

Actually you are correct.

My plan if I ever get a smart meter is to set it to charge at the start of the cheapest ev rate window.... So it's full in the two hours.... But extend the time to run until just before day rate

I think once my battery is full the inverter will drop the charge rate to near zero anyway... Correct me if I'm wrong.

If it's a low roof (like shed or kitchen extension or bungalow) then yeah, it's easy and safe enough to hop on and replace one. I've done the panels on all my low roofs myself, not even needed a ladder. Completely different ballgame on your high roof though, but I guess some people have no problem to go up there either.

Personally I've seen optimizers used by people around me not only not really doing what is on the tin, but also failing at an alarming rate. I'd stay clear. But YMMV. Also when I was buying most of my panels I got them cheaply, an optimizer would have added nearly 50% to the cost of a panel. Wrecking the pay back time. And that's not on a south facing non-shaded, 100% performing panel of course. They don't need optimizers. The panels that people fit optimizers to already have compromised output, even with the optimizer.

Thanks I've already set to 100.. i will try 150..

I have a kstar inverter and notice at this time of year I can get “low volts warning”,so to stop or reduce this happening I would put the inverter into battery priority mode,which will charge to 100%,.I had the inverter set to self consume and the battery to charge to 90% at 10ampsfrom 1.00 to 10.00 and then to discharge to soc 20%.That seemed to work fine,but after a week or so I was getting the low battery warning.Maybe it needs to be set to battery priority On a more regular basis.I get that it cannot discharge when in battery priority.I don’t see the option to set a second charge time slot in the menu’s.It is there in time of use mode,but the inverter was always set to self consume..?

If you are on the night rate and charging batteries is it better for the batteries to charge them slowly over the length of the night rate or just let them charge up at max current?

I had thought it better to let them trickle charge to protect them but the installer was very much just let them at it max wattage there’ll be no issue. They’re dyness b4850 (not popular here I know 🫣) but I didn’t have the space or confidence for a self build yet.

That’ll be phase two on my south facing garage.

I think your generally fine charging at max wattage, that's why they have a max limit. That said, why wouldn't you charge at a lower rate if you have a 9 hr window of night rate? As in what would be the advantage to charge at full tilt?

Depends on your battery. Many of us with the DIY batteries use CALB cells that can charge and discharge at 0.5C continuously. So if you have a 20kWh pack, it can charge at 10kW no bother at all, all day and all night.

Even getting a victron 15kva quattro (the largest single phase I could find).. what if you want 30kWp of panels.

There has to be a way of doing it. At this point I've pretty much accepted that the batteries I have (Dyness A48100) will not be part of my future setup, and neither will my Solis. But I dont want to make any more mistakes!