Adding solar to inverter-battery systems 101

Khinah23 said:
The problem is with charging, hence the solar idea. Inverter doesn't get time enough to fully charge battery during their loadshedding, off line and usage times.
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Sure, I get you, but solar isn't fool proof either. There will be days when solar output won't be enough, and then there is still nighttime use.

So the LA's will get stuffed either way which is why I recommended LFP (LFP doesn't care if it isn't charged properly and charges much quicker), and don't worry about the added expense of solar, or do both.
 
AlphaJohn said:
Doesnt matter where they connected, can even connect inverter at the MPPT battery feed, as long as its the shared + and - from the battery. :p

Above is my setup, and it so that I don't need extra fuses
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You got fuses on both battery poles?
 
Can I not just then add an additional 10amp battery tickle charger to assist the inverter charger during the times she does have electricity?
 
wingnut771 said:
I would like to see 100A go through the MPPT terminals, or even fitting 35mm² cable in them. It's non sensical taking the load from the controller with a long cable, enjoy the voltage drop.
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why would you want to use 35mm sq cables on a load like 100amp .thats a bit of overkill
 
Khinah23 said:
Can I not just then add an additional 10amp battery tickle charger to assist the inverter charger during the times she does have electricity?
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You can add a 100A charger, it won't speed up absorption phase as its the battery's resistance that is holding things up, this is the nature of LA batteries, very long absorption time. If you put a clamp meter on the battery cable, you will see only a fraction of the amps that the "lelela" can provide flowing through.

Also, the charger with the higher volts will do all the charging.
 
wingnut771 said:
future proofing /s

clearly I was exaggerating, hows 25mm² then, will those fit?
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aahha .25mm gives you ac or dc depending on conditions gives you 150 amp and 180 amp continuous .on 100 amp i would happily approve 16mm sq that is if copper and not ccc as ive seen in so many happy installs that end up being not so happy.nothing wrong with 35 but damn 200 amp upwards is heavy
 
wingnut771 said:
So for 4 hours 80Wh x 4 = 320Wh / 0.8 = 400Wh x 2 = 800Wh

800Wh / 12V = 67Ah

200Ah is plenty if you have enough time to recharge it, or get a 100Ah LFP.
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Last two questions....

1...You use 0.8 in your calculation, can I ask why, what is the 0.8 suppose to be for?
2....Do you have a calculation to determine the right size solar panel to be use to charge specific batteries?
 
soulie said:
aahha .25mm gives you ac or dc depending on conditions gives you 150 amp and 180 amp continuous .on 100 amp i would happily approve 16mm sq that is if copper and not ccc as ive seen in so many happy installs that end up being not so happy.nothing wrong with 35 but damn 200 amp upwards is heavy
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The point I'm trying to make is you don't connect the inverter to the MPPT controller.
 
Khinah23 said:
Last two questions....

1...You use 0.8 in your calculation, can I ask why, what is the 0.8 suppose to be for?
2....Do you have a calculation to determine the right size solar panel to be use to charge specific batteries?
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1. inefficiencies/losses.
2. I would make sure there is enough watts to cover the load and charge the battery. So you have an 80W load and you want to charge at 10A (12Vx10=120W), so 120W + 80W = 200W minimum panel, but seeing you have a 500W controller, I would just max out the controller for the cloudy days.
 
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Khinah23 said:
I did ask their technical team, they said I can damage the inverter by adding solar as an additional charging component as the lalela inverter is not solar compatible to start of with.... Maybe explain to me how you see this for example .....Panel to charger controller to battery and inverter to battery???
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That's a load of BS from the technical team. This is how it works, you either have an inverter with a built in charge controller where you just connect the panels on thr dedicated port, Or you have an inverter without a built in charge controller, that is your Lalela, in this case you need an external charge controller to control the solar input to charge the battery.

Remember the charge controller has nothing to do with the inverter, it's job is to charge the battery, so don't ever allow anyone to tell you the nonsense of an inverter not being compatible with solar

It works exactly how you describe it so even know better than the technical people.
 
TheChamp said:
That's a load of BS from the technical team. This is how it works, you either have an inverter with a built in charge controller where you just connect the panels on thr dedicated port, Or you have an inverter without a built in charge controller, that is your Lalela, in this case you need an external charge controller to control the solar input to charge the battery.

Remember the charge controller has nothing to do with the inverter, it's job is to charge the battery, so don't ever allow anyone to tell you the nonsense of an inverter not being compatible with solar

It works exactly how you describe it so even know better than the technical people.
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"technical team" lol, probably sales reps.

Is this the same as the mecer? Also have 10/20A setting? Also have fan not coming on issue with LFP?
 
TheChamp said:
That's a load of BS from the technical team. This is how it works, you either have an inverter with a built in charge controller where you just connect the panels on thr dedicated port, Or you have an inverter without a built in charge controller, that is your Lalela, in this case you need an external charge controller to control the solar input to charge the battery.

Remember the charge controller has nothing to do with the inverter, it's job is to charge the battery, so don't ever allow anyone to tell you the nonsense of an inverter not being compatible with solar

It works exactly how you describe it so even know better than the technical people.
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erm. can the inverter handle the higher charge voltage that the
impracticaldogg said:
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?
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TS-MPPT-60 | Morningstar 150 V dc Solar Charge Controller 45 A | RS

za.rs-online.com za.rs-online.com
have a look at this guy. Held one for emergency due to loadsheding until I could get my Kodac up.

it is fully programable and serves as an addon MPPT to run in paralelle with other chargers/inverters.
 
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