Wiring solar panels to two growatt invertors

[Buffalo]

Tried search, can I wire my solar array to two Invertors. I am installing a second invertor for split phase.

 

[FilterGuy]

NO...... but why do you need to? The panels on the 2nd inverter will still charge the batteries.

 

[Buffalo]

I have 24 volts of 271 ah now and am getting a eg4 200 ah and another invertor. Want to hook new battery to new invertor and keep diy battery on old invertor. The invertors are both growatt.
Thank you for any help.

 

[FilterGuy]

I have 24 volts of 271 ah now and am getting a eg4 200 ah and another invertor. Want to hook new battery to new invertor and keep diy battery on old invertor. The invertors are both growatt.
Thank you for any help.

Hmmmmm..... A few points.

• Is it supported to have the two inverters on separate batteries? I have not looked into it but I was told they must be on the same battery. (I don't know why that would be.....but that is what I was told)
  
  
• @Will Prowse regularly hooks LiFePO4 batteries of different capacities in parallel. It turns out that each one will draw a proportion of the current that is roughly equivalent to the ratio of the capacity to the total capacity. Wiring the batteries this way will give you access to the extra capacity of the larger battery. (If the batteries are separate when one battery gets low and its inverter drops out, all 'stacked' inverters drop out)
  
  
• If you decide to keep the batteries separate, you will probably have to split the solar array into two separate arrays.

 

[Buffalo]

Thanks for you help, I will have to dig a little deeper.

 

[RCinFLA]

Two MPPT controllers will fight each other trying to find max power point when connected to same PV array. If PV array power is greater than can be handled by one inverter then split into two arrays with each feeding separate inverter. If using separate batteries then there will no sharing of received PV power between AC split phases.

As to having separate batteries, if the inverters have cross control, when one shuts down, for any reason, the other will also shut down. This is a requirement if running 120vac inverters in series for 240vac split phase. Also, the cross control ensures they stay 180 degs phase relationship sync'd when running off grid or when grid goes down. You would not want your 240vac to drop half its supply when only one inverter shuts down or go willy-nilly phase drifting when grid goes down as that would corrupt 240vac output.

With separate batteries, whichever phase side is weakest link for capacity will set when system shuts down for depleted battery. If one side 120vac phase load is greater on weaker separate battery side than system capacity will suffer more.

 

[Buffalo]

Should I just parallel the battery's and leave aray hooked up to one invertor to charge batteries .

 

[FilterGuy]

Should I just parallel the battery's and leave aray hooked up to one invertor to charge batteries .

That seems like the best approach to me.

 

[Quattrohead]

I don't see why not and cannot confirm either way with a quick look. The panel bank will just look like a large variable power supply and each MPPT will grab what it can.

 

[Buffalo]

Thanks men, I just don't want to burn up good equipment.

 

[fatfash]

Hmmmmm..... A few points.

• Is it supported to have the two inverters on separate batteries? I have not looked into it but I was told they must be on the same battery. (I don't know why that would be.....but that is what I was told)
  
  
• @Will Prowse regularly hooks LiFePO4 batteries of different capacities in parallel. It turns out that each one will draw a proportion of the current that is roughly equivalent to the ratio of the capacity to the total capacity. Wiring the batteries this way will give you access to the extra capacity of the larger battery. (If the batteries are separate when one battery gets low and its inverter drops out, all 'stacked' inverters drop out)
  
  
• If you decide to keep the batteries separate, you will probably have to split the solar array into two separate arrays.

This is also true in my case. I have 302AH, 272AH & 280AH batteries connected in parallel with different BMS and the current during charge and discharge were very close.