Hey everyone, another new idiot to solar mastery

[Mattb4]

I never found any use for the SOL setting myself. SBU is my choice since Uti would make the unit more of an emergency backup instead of running on PV and battery. Your 28.8v (setting #9) might be a bit high. The default is 28.4 if LiFePO4 battery type LF08 is selected in Setting #8. Occasionally a new LiFePO4 battery will be unbalanced and cause high DC bus voltage spikes as the BMS trips on a runner cell. If you find this happening drop your voltage down to 28.2v or 28.0v and see if that gets you by. Eventually the battery will balance and you can kick it back up but not really needed since the difference in 99% charged and 100% charged is rather meaningless.

You should have a setting #36 that is not mentioned in your manual. This is maximum PV amperage. Unless you need to limit how much your battery is getting from your array I would set it and the Max charge amperage setting #7 at the 80 amps.

24.6v for transfer to Main should work. I run mine at 24.0v and back to inverter at 26.8v Be aware that the low voltage alarm #14 must be set .2 volts higher than transfer #4 or it will alter the transfer voltage to that. Also #35 affects #5

ETA: BTW you can peel off the plastic display panel shipping protector with the little black tab on it.

 

[The new solar idiot]

I never found any use for the SOL setting myself. SBU is my choice since Uti would make the unit more of an emergency backup instead of running on PV and battery. Your 28.8v (setting #9) might be a bit high. The default is 28.4 if LiFePO4 battery type LF08 is selected in Setting #8. Occasionally a new LiFePO4 battery will be unbalanced and cause high DC bus voltage spikes as the BMS trips on a runner cell. If you find this happening drop your voltage down to 28.2v or 28.0v and see if that gets you by. Eventually the battery will balance and you can kick it back up but not really needed since the difference in 99% charged and 100% charged is rather meaningless.

You should have a setting #36 that is not mentioned in your manual. This is maximum PV amperage. Unless you need to limit how much your battery is getting from your array I would set it and the Max charge amperage setting #7 at the 80 amps.

24.6v for transfer to Main should work. I run mine at 24.0v and back to inverter at 26.8v Be aware that the low voltage alarm #14 must be set .2 volts higher than transfer #4 or it will alter the transfer voltage to that. Also #35 affects #5

ETA: BTW you can peel off the plastic display panel shipping protector with the little black tab on it.

Awesome thanks for the setting help. I have adjusted it as you stated. Unit appears to be working I only have my car set up right now though I did test my pump and it is running at 15 amps at 75% usage and it looks like it takes roughly just under 2 hours to get 7% charge so essentially I get about 11 hours a day of sun that could potentially yield me maybe 35-40% or so of charge. Better than I expected if I'm reading it right.

 

[Mattb4]

Awesome thanks for the setting help. I have adjusted it as you stated. Unit appears to be working I only have my car set up right now though I did test my pump and it is running at 15 amps at 75% usage and it looks like it takes roughly just under 2 hours to get 7% charge so essentially I get about 11 hours a day of sun that could potentially yield me maybe 35-40% or so of charge. Better than I expected if I'm reading it right.

Your AIO'S display is showing you are in bypass with both PV and AC charging (battery charged so charge light is off). Is that what you want?

 

[The new solar idiot]

Your AIO'S display is showing you are in bypass with both PV and AC charging (battery charged so charge light is off). Is that what you want?

Idk. Shouldn't it be running purely off solar right now until suns goes down the grid power? I thought anyhow.

 

[Mattb4]

Idk. Shouldn't it be running purely off solar right now until suns goes down the grid power? I thought anyhow.

I would double check your settings. From the display screen in the image you were running off AC from the grid this is typical of a Uti mode. You will notice no lines to the inverter (icon not even showing) from your battery or the PV and than to the load. Yes the PV will charge the battery alongside your grid but once the battery is full it has no load without the inverter operating. Also be aware that if you are running from the inverter you can not charge from AC in.

Your AIO in SBU or SOL will prefer PV/battery if available. In UTI it prefers grid.

Edit to add: Here is an image of what you should see when battery is charged and PV is supplying load. Note the arrows and lines. There is none to the battery from PV (not charging) Line from battery to inverter and line from PV to inverter.

 

[sunshine_eggo]

Idk. Shouldn't it be running purely off solar right now until suns goes down the grid power? I thought anyhow.

Nope. It's clearly in bypass charging battery with grid and PV.

Your battery capacity is so small, it will take almost no time to deplete them - about 20-30 minutes at that rate if they tolerate a 75A discharge at all.

it is running at 15 amps at 75% usage and it looks like it takes roughly just under 2 hours to get 7% charge so essentially I get about 11 hours a day of sun that could potentially yield me maybe 35-40% or so of charge. Better than I expected if I'm reading it right.

You are not reading it right. 15A @ 120V = 1800W

To run that for 11 hours, you'd need at least 4000W of solar in ideal conditions with perfect tilt and orientation with no shade from sunrise to sunset, and at least 10-15kWh of battery capacity to hope to be able to capture and use it.

 

[The new solar idiot]

I see what you're saying now there's no arrow from the battery to the inverter or whatever that picture is. Option number one is set to SOL

 

[sunshine_eggo]

If PV is > loads, the PV is both charging the battery and supplying the loads, so there is technically nothing going from battery to loads.

 

[The new solar idiot]

If PV is > loads, the PV is both charging the battery and supplying the loads, so there is technically nothing going from battery to loads.

Yes this makes sense. Battery is used to basically bump start it then to stabilize it if clouds over and cannot maintain. Yes 100% sun today from 630am to 730pm

 

[The new solar idiot]

Now the car is charging.off it at 15a and the pond pump going . It switches from grid to PV off and on every 60 secs. Then after30 mins I get error 4 then goes back to normal

 

[Mattb4]

Your battery is dropping in voltage to below transfer to grid setting. Error number 4 is a low battery voltage indication. That tells me the batteries BMS likely tripped. Note the high voltage of 29.3 indicated. This is not your battery voltage but the DC bus voltage.

What batteries do you have and how are they connected.

 

[The new solar idiot]

Your battery is dropping in voltage to below transfer to grid setting. Error number 4 is a low battery voltage indication. That tells me the batteries BMS likely tripped. Note the high voltage of 29.3 indicated. This is not your battery voltage but the DC bus voltage.

What batteries do you have and how are they connected.

That could be the problem and also what I was thinking. I have two of these https://amzn.to/4azLMxT . 12v 50ah in series to 24v. One battery though is always lower even after equalizing them over night in parallel. I only ordered these because the seller recommended them to be ran this way. Would I be better off getting a single 24v 50ah Instead? Another member mentioned this problem but since the batteries were listed to be used like this I assumed (prob shouldnt have) that the two bms wouldn't be an issue

 

[42OhmsPA]

I think you're going to need a lot more battery capacity to keep C rates in check.
That 50 amp BMS in the battery you linked is probably protecting at anything over ~700 watts.
I'd definitely go with a 24V battery / batteries.

 

[sunshine_eggo]

You need a battery rated to deliver the current needed to sustain the intended load.

1800W / 24V /.85 = 88A minimum.

 

[The new solar idiot]

You need a battery rated to deliver the current needed to sustain the intended load.

1800W / 24V /.85 = 88A minimum.

Ok so back to basics. Reality is I should not be charging a car and that's ok. Plain out! But if I have 1800w to use in total, if I keep it below that threshold during typical daily use(assuming it's sunny), can I run purely off solar without beating the heck out of my battery(ies)? If so can I use the majority of the 1800w or is there a factored amount that is useable say 900w. And yes I know the amount of sunlight depicts this but with that aspect out of theory.

 

[CaliSunHarvester]

Ok so back to basics. Reality is I should not be charging a car and that's ok. Plain out! But if I have 1800w to use in total, if I keep it below that threshold during typical daily use(assuming it's sunny), can I run purely off solar without beating the heck out of my battery(ies)? If so can I use the majority of the 1800w or is there a factored amount that is useable say 900w. And yes I know the amount of sunlight depicts this but with that aspect out of theory.

My solar car charger has a 3000W inverter of which I only use 1400W for level 1 charging, I like to keep a reserve and I built it with two 24V 200Ah batteries. In parallel. They each have a 200A BMS, so I think I could pull in theory 400A with that setup. However, my wire is only good for 195A. In reality, 1400W output require about 60A on the DC side 1400/25 = 56A plus some for loss. My recommendation is to have at least one 24V battery with a 200A BMS.

After 2 months, I added a 3rd battery. No change in the 13 months since that.

 

[sunshine_eggo]

Ok so back to basics. Reality is I should not be charging a car and that's ok. Plain out! But if I have 1800w to use in total, if I keep it below that threshold during typical daily use(assuming it's sunny), can I run purely off solar without beating the heck out of my battery(ies)? If so can I use the majority of the 1800w or is there a factored amount that is useable say 900w. And yes I know the amount of sunlight depicts this but with that aspect out of theory.

Using typical BMS ratings, you can use 1800W for as long as the draw from the batteries does not exceed 50A.

PV power looks like a bell curve:



You can likely only use 1800W for ±X hours before and after high noon, or whenever your peak solar occurs.

 

[Mattb4]

Ok so back to basics. Reality is I should not be charging a car and that's ok. Plain out! But if I have 1800w to use in total, if I keep it below that threshold during typical daily use(assuming it's sunny), can I run purely off solar without beating the heck out of my battery(ies)? If so can I use the majority of the 1800w or is there a factored amount that is useable say 900w. And yes I know the amount of sunlight depicts this but with that aspect out of theory.

You can certainly see what you can operate and if your batteries work out for you. I do suspect you will find that you will want a 24vDC battery and more capacity than 50ah as time goes by.

 

[The new solar idiot]

Ok so one more question . I temporarily have my system disconnected because I don't want to spend 500 plus dollars on one single battery (24v 100ah) and everything is shut off but with power coming in through PV the inverter is beeping and won't stop so my question is can I run an on/off switch inline on the PV wire side to stop power coming in to me this kind of makes sense just like a breaker because high voltage is still coming to the house through the PV.

 

[sunshine_eggo]

Ok so one more question . I temporarily have my system disconnected because I don't want to spend 500 plus dollars on one single battery (24v 100ah) and everything is shut off but with power coming in through PV the inverter is beeping and won't stop so my question is can I run an on/off switch inline on the PV wire side to stop power coming in to me this kind of makes sense just like a breaker because high voltage is still coming to the house through the PV.

You can only use a suitable DC switch/breaker rated for both the peak voltage of the array and its current.

 

[Mattb4]

Ok so one more question . I temporarily have my system disconnected because I don't want to spend 500 plus dollars on one single battery (24v 100ah) and everything is shut off but with power coming in through PV the inverter is beeping and won't stop so my question is can I run an on/off switch inline on the PV wire side to stop power coming in to me this kind of makes sense just like a breaker because high voltage is still coming to the house through the PV.

Yes most people establish a 2 pole DC breaker before AIO to act as a on/off to remove PV input. Just make sure to wire it properly.

Incidentally if you can wait 2 months you can get a 24vDC 100ah battery for around $272 (there is a $30 Aliexpress Spring discount at the moment).

May not be the best quality nor have the rated capacity but I have found them to work.

 

[The new solar idiot]

I think this should suffice https://amzn.to/3vVWTSR

 

[The new solar idiot]

Ok so that works perfect. Also I picked up a 24v 100ah battery off temu last night for 300usd. Kinda sketchy thought but it's locally shipped and almost the same price as a 60ah on Amazon so even if it isn't 100% as advertised it should be still better. I will keep you all updated.

 

[The new solar idiot]

Finally got the new battery and man it's big. Heavy too (obviously not lead acid heavy). I will let it run today for sometime in the clear sunny sky and see how it does.

 

[sunshine_eggo]

LOL... fucking TEMU... my wife orders from them constantly...