Which bit of hardware takes priority?

[bds70]

So as I near the moment of putting my new diy solar together in my bus I have been watching many videos and reading lots on here.
My question is the numerous settings on various bits of hardware.

Starting with the MPPT, then the BMS, then the Victron smart shunt, and the two Victron 3000w inverters. Each have their own settings, but which takes priority over which.

I know the BMS settings protect the battery and the MPPT settings should be inside that. (By inside I am presuming that means less or lower, is that right?)
But what do the smart shunt settings affect and then of course the inverters also have battery and charge settings.
It is somewhat confusing.

Can I get a "Road map" so to speak from the experts.

Thanks

 

[timselectric]

It sounds like you have mostly Victron equipment.
So I will page the Victron guru.
@sunshine_eggo

 

[wpns]

I’m sure Eggo will be along in a bit, in the meantime what are all the parts you are talking about? Panels (Voc,Isc at a minimum) and arrangement (serial, parallel, etc), charge controller, batteries (volts, AH, etc), inverters and connections, overcurrent protections, switches, breakers, fuses. The more details you provide the more help the experts can provide.

 

[DIYrich]

Mppt and inverter are normal operating settings. BMS and shunt are protection settings if something goes wrong, like both the mppt and inverter try to charge at the same time.

Operating settings are within the protection settings. Shunt protects all batteries. BMS protects each battery. Shunt may allow 300 amps for all batteries, but the BMS may allow only 100 amps for the one battery.

 

[bds70]

I’m sure Eggo will be along in a bit, in the meantime what are all the parts you are talking about? Panels (Voc,Isc at a minimum) and arrangement (serial, parallel, etc), charge controller, batteries (volts, AH, etc), inverters and connections, overcurrent protections, switches, breakers, fuses. The more details you provide the more help the experts can provide.

The whole system minus the batteries has been in-service for some years so that's all good. It was originally set up commercially, then I added 3 new 400w panels in series, a second victron MPPT 150/100 and a second multiplus 3000w. I couldn't parallel the inverters because the original multiplus was too old and not compatible anymore. At the moment I only have the original shunt, not the smart shunt.

Batteries will be 4 x 12v x 280AH in parallel.

I guess what I am asking is sort of like, driving a car, no good stepping on the gas if the engine isn't going, or using the brakes if the vehicle is not moving. There's a priority hierarchy to get the best out of the vehicle. I assume a similar electrical hierarchy should exist in terms of efficiency and power production of the system in totality.

Sheesh I hope that made sense.

 

[bds70]

Mppt and inverter are normal operating settings. BMS and shunt are protection settings if something goes wrong, like both the mppt and inverter try to charge at the same time.

Operating settings are within the protection settings. Shunt protects all batteries. BMS protects each battery. Shunt may allow 300 amps for all batteries, but the BMS may allow only 100 amps for the one battery.

Okaaay. So for example if the BMS is set for max charge at 3.45v then the MPPT and inverter would be set for let's say 3.44v max (13.76v) similarly the low voltage cutoff at 2.5v at the BMS would have a charge cuttoff at the MPPT of 2.6v (10.4v)
Am I on the right track?

 

[DIYrich]

BMS low voltage of 2.50v per cell to protect cells.
BMS high voltage of 3.65v per cell to protect cells.

That works out to 10.0v - 14.6v for 4 cells. But, since each cell voltage will vary, the BMS will cutoff before 10.0v and 14.6v to protect cells.

MPPT can be set to charge at 14.5v, and float at 13.6v.

Inverter, same charge settings, and low voltage cutoff at 11.0v.

If the BMS disconnects, then adjust charge or discharge settings of the MPPT and Inverter.

 

[Skypower]

If you have the high cell protect set too low it’s going to be constantly doing charge disconnect. The bms is the last line of defense and hopefully doesn’t have to do a thing but report and balance over 3.4 volts. My inverter is set to 3.45 vpc yet the bms has the high cell protect to 3.65 and recovery at 3.60. Remember, once your battery reaches full charge, you could have a pretty big delta(voltage difference between cells) some much higher than the average of the whole battery until the balance has had time to work on it.

 

[sunshine_eggo]

So as I near the moment of putting my new diy solar together in my bus I have been watching many videos and reading lots on here.
My question is the numerous settings on various bits of hardware.

Starting with the MPPT, then the BMS, then the Victron smart shunt, and the two Victron 3000w inverters. Each have their own settings, but which takes priority over which.

I know the BMS settings protect the battery and the MPPT settings should be inside that. (By inside I am presuming that means less or lower, is that right?)
But what do the smart shunt settings affect and then of course the inverters also have battery and charge settings.
It is somewhat confusing.

Can I get a "Road map" so to speak from the experts.

Thanks

If BMS is in control of the GX device, the BMS dictates parameters for all chargers. As a safety measure, you should still program all chargers for appropriate voltages.

MPPT, shunt and inverter settings are only relevant for the specific device and has no priority over other devices.

If BMS is not in control of the system, it's simply a safety device that should be programmed for the operational limits of the cells. The equipment should be programmed to ALWAYS operate INSIDE the limits of the BMS such that the BMS only activates protection when something goes wrong - not as a means of routine operation.

You can DECREASE charge voltage and current of all GX connected chargers with DVCC, i.e., if you override the chargers' settings with DVCC, they will respond to LOWER voltage and current, but you can't override with higher voltage/current with DVCC.

The whole system minus the batteries has been in-service for some years so that's all good. It was originally set up commercially, then I added 3 new 400w panels in series, a second victron MPPT 150/100 and a second multiplus 3000w. I couldn't parallel the inverters because the original multiplus was too old and not compatible anymore.

The second inverter output must be completely independent of the first. It can be connected to the same battery.

At the moment I only have the original shunt, not the smart shunt.

"original shunt" = ??

smartshunts aren't better than the BMV line, but they are cheaper.

Batteries will be 4 x 12v x 280AH in parallel.

Are these DIY batteries with independant BMS not in communication with the GX device?

I guess what I am asking is sort of like, driving a car, no good stepping on the gas if the engine isn't going, or using the brakes if the vehicle is not moving. There's a priority hierarchy to get the best out of the vehicle. I assume a similar electrical hierarchy should exist in terms of efficiency and power production of the system in totality.

Without BMS control, all components are configured independently.

Okaaay. So for example if the BMS is set for max charge at 3.45v then the MPPT and inverter would be set for let's say 3.44v max (13.76v) similarly the low voltage cutoff at 2.5v at the BMS would have a charge cuttoff at the MPPT of 2.6v (10.4v)
Am I on the right track?

Conceptually? Yes. Specific values? No. Set the BMS to the actual cell limits. Tailor your charge/discharge voltages to what you want to accomplish.

 

[bds70]

If BMS is in control of the GX device, the BMS dictates parameters for all chargers. As a safety measure, you should still program all chargers for appropriate voltages.

MPPT, shunt and inverter settings are only relevant for the specific device and has no priority over other devices.

If BMS is not in control of the system, it's simply a safety device that should be programmed for the operational limits of the cells. The equipment should be programmed to ALWAYS operate INSIDE the limits of the BMS such that the BMS only activates protection when something goes wrong - not as a means of routine operation.

You can DECREASE charge voltage and current of all GX connected chargers with DVCC, i.e., if you override the chargers' settings with DVCC, they will respond to LOWER voltage and current, but you can't override with higher voltage/current with DVCC.




The second inverter output must be completely independent of the first. It can be connected to the same battery.



"original shunt" = ??

smartshunts aren't better than the BMV line, but they are cheaper.



Are these DIY batteries with independant BMS not in communication with the GX device?



Without BMS control, all components are configured independently.



Conceptually? Yes. Specific values? No. Set the BMS to the actual cell limits. Tailor your charge/discharge voltages to what you want to accomplish.

Thanks for that. The shunt is a Victron 500A/50Mv. Not the newer smart shunts.

The battery's are 4 diy 280ah 12v each with its own JK-B2A8S20P BMS

I don't have any GX devices and probably can't afford the cerbo and it's monitor. I have a Victron BMV 702.

 

[sunshine_eggo]

Thanks for that. The shunt is a Victron 500A/50Mv. Not the newer smart shunts.

The battery's are 4 diy 280ah 12v each with its own JK-B2A8S20P BMS

I don't have any GX devices and probably can't afford the cerbo and it's monitor. I have a Victron BMV 702.

Fan of the BMV-702. I have one.

Since you don't have a GX device, you have completely independent devices that don't communicate with one another in any way, so there's no discussion about which takes priority.

The inverter works according to how it's configured.
The MPPT works according to how it's configured.
The BMV works according to how it's configured.

 

[bds70]

Fan of the BMV-702. I have one.

Since you don't have a GX device, you have completely independent devices that don't communicate with one another in any way, so there's no discussion about which takes priority.

The inverter works according to how it's configured.
The MPPT works according to how it's configured.
The BMV works according to how it's configured.

Excellent. I didn't realise they all stayed independent without a gx system.

What's the benefits of the cerbo and monitor? In order for them to work do all parts have to be linked by software or hardware?

 

[sunshine_eggo]

Excellent. I didn't realise they all stayed independent without a gx system.

Some bluetooth enabled devices can be setup to work in a VE.Smart network and gain limited communication. This is primarily for the purpose of propagating shunt measured voltage, current and temperature to MPPT controllers for more accurate charging.

What's the benefits of the cerbo and monitor? In order for them to work do all parts have to be linked by software or hardware?

Full communication between all components. VRM remote access and 6 months of detailed data logging. This is my system 3.5 hours away:



I can upgrade firmware, change shunt/MPPT settings via VictronConnect on my phone and make inverter configuration changes by downloading, editing and uploading config files.

2. Introduction

www.victronenergy.com

 

[bds70]

Some bluetooth enabled devices can be setup to work in a VE.Smart network and gain limited communication. This is primarily for the purpose of propagating shunt measured voltage, current and temperature to MPPT controllers for more accurate charging.



Full communication between all components. VRM remote access and 6 months of detailed data logging. This is my system 3.5 hours away:

View attachment 225800

I can upgrade firmware, change shunt/MPPT settings via VictronConnect on my phone and make inverter configuration changes by downloading, editing and uploading config files.

2. Introduction

www.victronenergy.com

Might have to save some pennies and perhaps do some upgrading once I have got these new batteries into service. Everyone here is so helpful, I hope I can give back at some stage. Thanks

 

[sunshine_eggo]

Might have to save some pennies and perhaps do some upgrading once I have got these new batteries into service. Everyone here is so helpful, I hope I can give back at some stage. Thanks

If you haven't done so, you should setup a VE.Smart network between your shunt and MPPT.

1. Introduction

www.victronenergy.com

 

[bds70]

If you haven't done so, you should setup a VE.Smart network between your shunt and MPPT.

1. Introduction

www.victronenergy.com

I think I am out of luck with the VE.Smart network. Just read the manual and I think my original MPPT is too old. It's pre 2020.

 

[sunshine_eggo]

blue smart chargers are AC-DC chargers, not MPPT.

If your MPPT has native bluetooth, it's a smartsolar and can be put on a VE.Smart network.

 

[bds70]

blue smart chargers are AC-DC chargers, not MPPT.

If your MPPT has native bluetooth, it's a smartsolar and can be put on a VE.Smart network.

Oops my bad. Lol. Thanks for pointing that faux pas out.