AIO vs Victron

[DyslexicDancer]

I had a question for you guys.

I'm building an off grid cabin and and currently in the beginning stages of putting together my solar system, so far I've got my Solar Panels, ground mount, batteries, BMS, and 2 growatt AIO inverters.

But looking around online i really like the Victron equipment, and I'm wondering if the Quality of Victron would be worth the switch, but there's a bit of a catch from what I see.

i want to be able to use solar during the day to run the cabin, with excess solar being used to charge my battery, I can set the Growatt up this way if I've read the manual correctly, with solar priority going to the loads, the question is , would it be possible to use a Victron MPPT charge controller and a Victron inverter to achieve the same goal?

Looking at the Victron MPPT charge controller manual I dont really see a way to have solar power going to the cabin loads first before charging the battery, it looks like the MPPT charge controller cuts off solar once the battery is full, and I'd like to have my solar still powering the cabin during the day even once the battery is full.

Hope my question makes sense

Thanks in advance for the help

DD

 

[BradCagle]

The solar will go to the loads, and battery naturally. When the battery is full, the solar should still continue to power the loads.

I would prefer the Victron setup over the AIO stuff. If you buy a Victon MPPT, and a victron multiplus II inverter you pretty much have all the functionality of the AIO. Yes it will cost more, but it's more efficient, higher quality, and from a company that stands behind their products.

I have victron 150/85 MPPT, and I'm planning on getting a multiplus II. Just from my experience with the victron 150/85, it's far superior from everything else I've used.

 

[Charleswgibbs]

If for example you are getting 1000w pv input that is charging the batteries, and you turn on a 400w load, then pv power will automatically power the load and charging would decrease to 600w until you removed the load.

A battery can't be charged and discharged at the same time, so your loads won't draw battery power until pv power drops below your loads.

 

[Mattb4]

I had a question for you guys.

I'm building an off grid cabin and and currently in the beginning stages of putting together my solar system, so far I've got my Solar Panels, ground mount, batteries, BMS, and 2 growatt AIO inverters.

But looking around online i really like the Victron equipment, and I'm wondering if the Quality of Victron would be worth the switch, but there's a bit of a catch from what I see.

i want to be able to use solar during the day to run the cabin, with excess solar being used to charge my battery, I can set the Growatt up this way if I've read the manual correctly, with solar priority going to the loads, the question is , would it be possible to use a Victron MPPT charge controller and a Victron inverter to achieve the same goal?

Looking at the Victron MPPT charge controller manual I dont really see a way to have solar power going to the cabin loads first before charging the battery, it looks like the MPPT charge controller cuts off solar once the battery is full, and I'd like to have my solar still powering the cabin during the day even once the battery is full.

Hope my question makes sense

Thanks in advance for the help

DD

If you already have the Growatts you would have to be able to return them for your money back.

I don't expect you will find that there is any big difference in terms of what they output. Both will charge the battery while they supply loads. After all the battery is a load when it is discharged and attached to the DC common bus. In terms of quality or features (The Growatts have a on unit control panel and no other devices are needed to change settings.) the Victron probably is higher build quality and it allows an ecosystem of add on units with monitoring capability that exceeds the Growatts.

 

[DyslexicDancer]

The solar will go to the loads, and battery naturally. When the battery is full, the solar should still continue to power the loads.

I would prefer the Victron setup over the AIO stuff. If you buy a Victon MPPT, and a victron multiplus II inverter you pretty much have all the functionality of the AIO. Yes it will cost more, but it's more efficient, higher quality, and from a company that stands behind their products.

I have victron 150/85 MPPT, and I'm planning on getting a multiplus II. Just from my experience with the victron 150/85, it's far superior from everything else I've used.

That's good to know, I was really wanting to upgrade to Victron but was concerned that the Smart MPPT Charge controller would cut off current once the battery was full

From what I read LiFePO4 does not like to be on a float charge like older Lead acid batteries, so the MPPT charge controller cuts off current once the battery reaches the threshold that you program into the smart MPPT

I'm guessing that once a load is applied the Smart MPPT charge controller will sense this voltage drop and then provide just enough current to power the load without overcharging the battery?

 

[DyslexicDancer]

If for example you are getting 1000w pv input that is charging the batteries, and you turn on a 400w load, then pv power will automatically power the load and charging would decrease to 600w until you removed the load.

A battery can't be charged and discharged at the same time, so your loads won't draw battery power until pv power drops below your loads.

Right, I guess my concern is what happen with the Smart MPPT charge controller once it has stopped providing current once the battery is at 100% state of charge. it has to cut the charge current or it will over charge the battery

I'm guessing it must sense the voltage drop when a load is applied (and the battery is full) and then provide only enough current to power the load without overcharging the battery in the process of powering the load?

 

[Mattb4]

Right, I guess my concern is what happen with the Smart MPPT charge controller once it has stopped providing current once the battery is at 100% state of charge. it has to cut the charge current or it will over charge the battery

I'm guessing it must sense the voltage drop when a load is applied (and the battery is full) and then provide only enough current to power the load without overcharging the battery in the process of powering the load?

Doubtful. It would have to disconnect the battery from the common DC bus.

 

[DyslexicDancer]

Doubtful. It would have to disconnect the battery from the common DC bus.

So how does one prevent overcharging the battery and still have solar provide power to loads during the day without using the battery?

Isn't this what the AIO growatt inverter does with Solar priority to loads?

 

[BradCagle]

Doubtful. It would have to disconnect the battery from the common DC bus.

No, it just has to provide a slightly higher voltage than what the battery is resting at, and enough current to satisfy the load. If it does this correctly the load will be powered by the SCC only.

 

[BradCagle]

So how does one prevent overcharging the battery and still have solar provide power to loads during the day without using the battery?

Isn't this what the AIO growatt inverter does with Solar priority to loads?

The SCC senses the load, and just needs to keep the voltage high enough to be the voltage source.

 

[BradCagle]

BTW some charge controllers are faster at detecting the load than others, so you might notice power coming from your battery when a load starts up for a short period. But ultimately the controller will notice the voltage drop, and kick in.

 

[Mattb4]

No, it just has to provide a slightly higher voltage than what the battery is resting at, and enough current to satisfy the load. If it does this correctly the load will be powered by the SCC only.

So it is in essence charging the battery. Plus which loads come and go. The idea that you can divorce a DC common connected battery from it is as I said doubtful.

 

[BradCagle]

So it is in essence charging the battery. Plus which loads come and go. The idea that you can divorce a DC common connected battery from it is as I said doubtful.

No, if it does it correctly it will not charge the battery.

For simplicity lets say float is 13.5v, then a load come on, the load will pull that voltage down a bit, the SCC will sense this, and compensate to raise it back to 13.5v

In order to raise it back to 13.5v it has to fully satisfy the load current.

 

[Mattb4]

No, if it does it correctly it will not charge the battery.

For simplicity lets say float is 13.5v, then a load come on, the load will pull that voltage down a bit, the SCC will sense this, and compensate to raise it back to 13.5v

In order raise it back to 13.5v it has to fully satisfy the load current.

W=VA
Yes you can keep charger output with having a higher float value on the battery. I do this with my AIO in order to maximize solar production. However this comes by stressing the battery. In the case of the lithium I run the float should be quite a bit lower than Boost charge. Any controller that is doing as you claim is simply playing games with float settings.

SCC job is to charge a battery. Once the battery is charged it should discontinue or otherwise it runs the risk of overcharging.
ETA: FLA batteries are good for trickle charging that can keep a SCC in operating mode.

 

[BradCagle]

SCC job is to charge a battery. Once the battery is charged it should discontinue or otherwise it runs the risk of overcharging.
ETA: FLA batteries are good for trickle charging that can keep a SCC in operating mode.

It will not continue to charge the battery, it only provides enough current to run the load.

I've setup a lot of systems like this, in fact this is simply how it's supposed to work.

I can watch the BMSs on my own batteries, nothing goes in, or out when they are full, however the SCC is still powering loads.

 

[caki]

Back to the original question, a good analogy of battery charging and load sharing is if you think at it as water pipes. You battery is a water tank and the charger is the pump bringing water in. The load is a faucet. The pump goal is to keep the system at a certain pressure (charged). If is pumping water it is because either the faucet is open or the tank is not full. If the faucet is open the pump will work extra hard to keep the pressure and the water will flow to the faucet and if the tank is not full, also to the tank. If the pump stops (no solar) water would come from the tank.

Analogy aside, depending on the BMS, Victron equipment can also talk to the BMS and get the SOC state and stop charging when the battery is full based on the SOC and not on voltage levels. I'm impressed with the functionality of the Victron systems. Their VenusOS is opensource and you can expand it to include other sensors what makes monitoring really interesting.

 

[DyslexicDancer]

I appreciate the insight into how Victron will work for my application

So yeah, I'm really liking what I see with Victron. My only real concern was how a Victron system would manage powering loads once my battery was fully charged. I'm sure I'll need to figure out the charge settings to make it work correctly, but that's no problem, I had to do the same with the Growatt AIO

I have Tesla Solar and a Powerwall in my home and it's just awesome, Solar powers everything and charges the powerwall when their is extra power available, and once the powerwall is charged (usually before Noon) the solar powers my home and sends excess to the grid, I want my cabin to work this way..... minus the grid part I've tested the Growatt AIO Inverter and it was pretty simple to set-up and I was able to see that it powered my test load just fine off of solar once the battery was charged, looking at the JK BMS I could see that when my battery was at 100% SOC the battery was not being charged further and the Grwowatt AIO was powering a load off solar without issue.

Since it seems Victron will work in the same manner I'll be making the change over to their equipment, it just seems like it will be better equipment in the log run, not that Growatt is bad, I'll just feel more confident with Victron managing my off grid cabin's power system

 

[caki]

Notice that Victron supports a small number of batteries but this addon to the VenusOS can extend support to the JK BMS:

Victron VenusOS driver for serial connected BMS - JBD / Daly / ANT / JKBMS / Heltec / Renogy / Tian / ECS

I have created a VenusOS driver that can talk to BMS/Batteries that has serial communications (instead of the normal CANbus). RS485/RS232/TTL/UART and Venus 2.80+ have been tested. Currently it works with JBD BMS (LLT Power / Overkill Solar) Daly BMS (Daly Smart BMS / Daly Sinowealth based...

diysolarforum.com

 

[DyslexicDancer]

Notice that Victron supports a small number of batteries but this addon to the VenusOS can extend support to the JK BMS:

Victron VenusOS driver for serial connected BMS - JBD / Daly / ANT / JKBMS / Heltec / Renogy / Tian / ECS

I have created a VenusOS driver that can talk to BMS/Batteries that has serial communications (instead of the normal CANbus). RS485/RS232/TTL/UART and Venus 2.80+ have been tested. Currently it works with JBD BMS (LLT Power / Overkill Solar) Daly BMS (Daly Smart BMS / Daly Sinowealth based...

diysolarforum.com

Nice!!!

Thanks for the link

 

[USVISolarGuy]

I had a question for you guys.

I'm building an off grid cabin and and currently in the beginning stages of putting together my solar system, so far I've got my Solar Panels, ground mount, batteries, BMS, and 2 growatt AIO inverters.

But looking around online i really like the Victron equipment, and I'm wondering if the Quality of Victron would be worth the switch, but there's a bit of a catch from what I see.

i want to be able to use solar during the day to run the cabin, with excess solar being used to charge my battery, I can set the Growatt up this way if I've read the manual correctly, with solar priority going to the loads, the question is , would it be possible to use a Victron MPPT charge controller and a Victron inverter to achieve the same goal?

Looking at the Victron MPPT charge controller manual I dont really see a way to have solar power going to the cabin loads first before charging the battery, it looks like the MPPT charge controller cuts off solar once the battery is full, and I'd like to have my solar still powering the cabin during the day even once the battery is full.

Hope my question makes sense

Thanks in advance for the help

DD

Curious as to what you decided to do - I'm in the same boat - The Victron system seems a little more intense with many components. The AOI out there are all "simple".. But every professional i have spoke with says Victron is the way to go but for a smaller setup may be over kill