Adding solar to inverter-battery systems 101

[wingnut771]

For a quick and dirty short-term solution that wouldn't break the bank, I would just install one 420W solar panel and a Victron 75/15 charge controller, as here. According to the Victron charge controller's datasheet, it can handle up to 440W at 24V.
That means during the day, your batteries will last much longer if you've got load shedding. The batteries will also wear less since you'll probably not drain them as much during daytime load shedding.
If you don't have load shedding, you'll have the added benefit of the batteries charging faster since they will be charged by the inverter as well as the solar panel.

The solar panel will cost about ~R3000 and the charge controller R2000, R500 for cables the whole affair will set you back about R5500. And it is super easy to set up, just connect the batteries and solar panel to the charge controller, and it'll do its thing. The charge controller I linked has the ability to connect to your phone via Bluetooth that way you could configure it for your lithium batteries.

If your base load is about 400W (that's the internet, a TV and a few lights), you'll basically use no battery power during daytime load shedding and your batteries will stay full for nighttime load shedding.

This is not true. The one with the higher voltage will charge the battery.

 

[AlphaJohn]

For a quick and dirty short-term solution that wouldn't break the bank, I would just install one 420W solar panel and a Victron 75/15 charge controller, as here. According to the Victron charge controller's specs, it can handle up to 440W at 24V.
That means during the day, your batteries will last much longer if you've got load shedding. The batteries will also wear less since you'll probably not drain them as much during daytime load shedding.
If you don't have load shedding, you'll have the added benefit of the batteries charging faster since they will be charged by the inverter as well as the solar panel. <- This is not true, as pointed out by wingnut771

The solar panel will cost about ~R3000 and the charge controller R2000, R500 for cables the whole affair will set you back about R5500. And it is super easy to set up, just connect the batteries and solar panel to the charge controller, and it'll do its thing. The charge controller I linked has the ability to connect to your phone via Bluetooth that way you could configure it for your lithium batteries.

If your base load is about 400W (that's the internet, a TV and a few lights), you'll basically use no battery power during daytime load shedding and your batteries will stay full for nighttime load shedding.

Or just use https://www.communica.co.za/products/sr-ml2420-mppt-solar-controller?variant=17184883310665

I have the 30A one on Mecer 1440 (24V) with 2 x 250W 30V panels with 24V LFP and my area had no power for the past week. Not buigging me too much

When I get home I switch on Fan, TV & lights as normal and my battery charge during the day.

The only F-up is that seeing that I am one of the few that have lights, I get all the bloody mozzies come visit so I have to constantly stock up on Peacfull sleep.

Also, If I need extra power I can fire up the 2.8Kva Genny.

 

[grok]

Or just use https://www.communica.co.za/products/sr-ml2420-mppt-solar-controller?variant=17184883310665

I have the 30A one on Mecer 1440 (24V) with 2 x 250W 30V panels with 24V LFP and my area had no power for the past week. Not buigging me too much

When I get home I switch on Fan, TV & lights as normal and my battery charge during the day.

The only F-up is that seeing that I am one of the few that have lights, I get all the bloody mozzies come visit so I have to constantly stock up on Peacfull sleep.

Also, If I need extra power I can fire up the 2.8Kva Genny.

Mi Scusi but why is your suggestion better than what was suggested?

Not being pedantic just want to learn from everybody else's experience/mistakes..

 

[AlphaJohn]

Mi Scusi but why is your suggestion better than what was suggested?

Not being pedantic just want to learn from everybody else's experience/mistakes..

The one I linked:

I have the 2430 for the same price as the Victron, but sadly that is sold out.

Victron 75/15 Originally linked


So R500 more for 5A less max charge

If you not to phased on the display you can even get a 30A one for less

SR-MC2430N10 MPPT CONTROLLER

Srne SR-MC2430N10 MPPT CONTROLLER Solar MPPT Solar Controller 12/24V, 30AMPSolar Controller 12/24V 30AMP Feature PowerCatcher maximum power point tracking technology allows the controller to track the maximum power point of solar panels even in a complex environment. Compared with the...

www.communica.co.za

Whatever you do just do not go PWM.

 

[Stonemason]

The existing inverter has been connected into the DB board already .

I hope your Mercer 2400 is pure sine and not modified sine. If it is modified sine, I hope you are only running lights and your TV on that circuit because if you run your fridge on such an inverter you will soon have to find a new way to keep your beer cold.

 

[wingnut771]

The one I linked:
View attachment 1460381
I have the 2430 for the same price as the Victron, but sadly that is sold out.

Victron 75/15 Originally linked
View attachment 1460383

So R500 more for 5A less max charge

If you not to phased on the display you can even get a 30A one for less

SR-MC2430N10 MPPT CONTROLLER

Srne SR-MC2430N10 MPPT CONTROLLER Solar MPPT Solar Controller 12/24V, 30AMPSolar Controller 12/24V 30AMP Feature PowerCatcher maximum power point tracking technology allows the controller to track the maximum power point of solar panels even in a complex environment. Compared with the...

www.communica.co.za

Whatever you do just do not go PWM.

How do you change settings with no display?

 

[impracticaldogg]

I hope your Mercer 2400 is pure sine and not modified sine. If it is modified sine, I hope you are only running lights and your TV on that circuit because if you run your fridge on such an inverter you will soon have to find a new way to keep your beer cold.

Yes, just lights and computers. The laptops are fine but the (older) desktops sometimes shut down when the power switches to or from the grid

 

[AlphaJohn]

How do you change settings with no display?

Suppose:

SOLAR BLUETOOTH MODULE SR-BT-2

Srne SOLAR BLUETOOTH MODULE SR-BT-2 Solar Bluetooth add on Module, For MC Series MPPT Solar Controller.Bluetooth add on Module Features BT-1、BT-2 is a suitable for our company solar controller extend bluetooth communication function of the bluetooth module,cooperate with mobile phone APP can be...

www.communica.co.za

or

SR-RM6 EXTERNAL LCD DISPLAY

Srne SR-RM6 EXTERNAL LCD DISPLAY Solar New SRNE External LCD Display, Suitable for all MC Series Solar MPPT Controller, Product Size :104.5 x 55.5 x 11.8mm External LCD Display Additional Information Device LCD Display Type External

www.communica.co.za

 

[grok]

How do you change settings with no display?

OP post..

The charge controller I linked has the ability to connect to your phone via Bluetooth that way you could configure it for your lithium batteries.

 

[wingnut771]

Suppose:

SOLAR BLUETOOTH MODULE SR-BT-2

Srne SOLAR BLUETOOTH MODULE SR-BT-2 Solar Bluetooth add on Module, For MC Series MPPT Solar Controller.Bluetooth add on Module Features BT-1、BT-2 is a suitable for our company solar controller extend bluetooth communication function of the bluetooth module,cooperate with mobile phone APP can be...

www.communica.co.za

or

SR-RM6 EXTERNAL LCD DISPLAY

Srne SR-RM6 EXTERNAL LCD DISPLAY Solar New SRNE External LCD Display, Suitable for all MC Series Solar MPPT Controller, Product Size :104.5 x 55.5 x 11.8mm External LCD Display Additional Information Device LCD Display Type External

www.communica.co.za

Cheaper to get this then:

SR-ML2420 MPPT SOLAR CONTROLLER

Srne SR-ML2420 MPPT SOLAR CONTROLLER Solar MPPT High Efficiency, Solar Charge Controller, 20A(260W/12V, 520W/24V), 12V/24V Autoswitch, Maximum input voltage:100V.MPPT High Efficiency Solar Charge Controller Feature With the advanced dual-peak or multi-peak tracking technology, when the solar...

www.communica.co.za

 

[wingnut771]

OP post..

only with the addons.

 

[AlphaJohn]

Cheaper to get this then:

SR-ML2420 MPPT SOLAR CONTROLLER

Srne SR-ML2420 MPPT SOLAR CONTROLLER Solar MPPT High Efficiency, Solar Charge Controller, 20A(260W/12V, 520W/24V), 12V/24V Autoswitch, Maximum input voltage:100V.MPPT High Efficiency Solar Charge Controller Feature With the advanced dual-peak or multi-peak tracking technology, when the solar...

www.communica.co.za

View attachment 1460415

Ie the one I linked originally

PS you can still use the Bluetooth unit on that one as well

 

[wingnut771]

Ie the one I linked originally

Adding solar to inverter-battery systems 101

For a quick and dirty short-term solution that wouldn't break the bank, I would just install one 420W solar panel and a Victron 75/15 charge controller, as here. According to the Victron charge controller's datasheet, it can handle up to 440W at 24V. That means during the day, your batteries...

mybroadband.co.za

Yes that's where is got the link from but why post the other one then?

 

[AlphaJohn]

Yes that's where is got the link from but why post the other one then?

Cause it has more scalability. If you want more panels.

On the 2430 you can use 2 x 400W panels

 

[wingnut771]

Cause it has more scalability. If you want more panels.

On the 2430 you can use like 2 x 400W panels

Oh, I didn't look at the specs. I just saw 30A.

800W for those cloudy shitty days.

 

[TheRoDent]

I have some pretty beefy lithium batteries and a basic (Mecer 2400) inverter that works well. Now that loadshedding has gone up so much I'm looking at integrating some solar panels to top up the batteries. As I don't trust the grid to be able to do that before the power goes down again.

What are the basic principles here? I need a more sophisticated inverter (estimate 10k) to handle input from the panels. The panels need to generate enough power to make up for the battery drain. From what I've seen at a friend's place you use batteries to store energy from the panels so the main batteries can also be topped up at night. So they balance out the supply when the panels can't generate energy.

The existing inverter has been connected into the DB board already - so the bulk of the cost should be the purchase and installation of the panels, the new inverter and balancing batteries.

Are there some rules of thumb to calculate the capacity of panels and balancing batteries needed to top up an existing battery installation?

A hybrid inverter will suit your needs. The Kodak OG5.48 is around 10k (ex VAT) from Segen Solar.

KODAK Solar Off-Grid Inverter King with UPS 5kW 48V | SegenSolar

segensolar.co.za

Beware though that their MPPT's can handle a maximum of 140vDC input from the solar panels, so you can typically do a maximum of around 6 panels, in a three per-string configuration.

The Kodak inverters are an OEM rebrand of Voltronics' famous "Axpert" range of inverters. Mecer, RCT and a couple of other companies also OEM them in South Africa. They're pretty well known.

What type of lithium batteries do you have, as this inverter is a 48v system?

 

[wingnut771]

A hybrid inverter will suit your needs. The Kodak OG5.48 is around 10k (ex VAT) from Segen Solar.

KODAK Solar Off-Grid Inverter King with UPS 5kW 48V | SegenSolar

segensolar.co.za

Beware though that their MPPT's can handle a maximum of 140vDC input from the solar panels, so you can typically do a maximum of around 6 panels, in a three per-string configuration.

The Kodak inverters are an OEM rebrand of Voltronics' famous "Axpert" range of inverters. Mecer, RCT and a couple of other companies also OEM them in South Africa. They're pretty well known.

What type of lithium batteries do you have, as this inverter is a 48v system?

This is a hybrid inverter, the Kodak is not as it can't feed into the grid:

 

[TheRoDent]

This is a hybrid inverter, the Kodak is not as it can't feed into the grid:
View attachment 1460465

Yes, I guess it depends on what Hybrid means to you. I see that generally people label Hybrid inverters as inverters that can blend between solar, grid, and battery, and aren't grid-tied.

The Sunsynk's are nice as you can drive noncritical load upwards on the Eskom side, but then you need a CT clamp to ensure that you don't feedback into the grid (unless you're in Cape Town I suppose, and want to do that).

I have one of these 8kw Sunsynk's, and a Mecer Axpert King 5kw.

The Sunsynk is definately the more advanced unit, and can even handle a generator input directly, obviating the need for a transfer switch.

Pricey though.

 

[wingnut771]

Yes, I guess it depends on what Hybrid means to you. I see that generally people label Hybrid inverters as inverters that can blend between solar, grid, and battery, and aren't grid-tied.

The Sunsynk's are nice as you can drive noncritical load upwards on the Eskom side, but then you need a CT clamp to ensure that you don't feedback into the grid (unless you're in Cape Town I suppose, and want to do that).

I have one of these 8kw Sunsynk's, and a Mecer Axpert King 5kw.

The Sunsynk is definately the more advanced unit, and can even handle a generator input directly, obviating the need for a transfer switch.

Pricey though.

The inverter would come with the CT clamp.

 

[impracticaldogg]

A hybrid inverter will suit your needs. The Kodak OG5.48 is around 10k (ex VAT) from Segen Solar.

KODAK Solar Off-Grid Inverter King with UPS 5kW 48V | SegenSolar

segensolar.co.za

Beware though that their MPPT's can handle a maximum of 140vDC input from the solar panels, so you can typically do a maximum of around 6 panels, in a three per-string configuration.

The Kodak inverters are an OEM rebrand of Voltronics' famous "Axpert" range of inverters. Mecer, RCT and a couple of other companies also OEM them in South Africa. They're pretty well known.

What type of lithium batteries do you have, as this inverter is a 48v system?

2 x 218Ah Blue Novas