Help! Charge PylonTech batteries from generator via Solis Inverter in Off-Grid mode.

[davidwellan]

Hi,

I have a Solis RHI-3K-48ES-5G Hybrid Inverter connected to 2 x PylonTech US3000C batteries and 10 x 370W panels.

I have set the whole system up myself and it works great!

I need to understand how to connect my 3kw generator to the Solis inverter and charge the batteries, now we are getting shorter days.

We are completely off-grid and have no grid connection. The inverter is connected to our power supply via AC Backup and the inverter is setup in Off Grid mode.

Any help would be greatly appreciated.

Thanks, David

 

[SeaGal]

Welcome. I have on-grid RHI and EH1P Solises.

Unfortunately, I don't believe it is possible to add a generator to the Solis. It doesn't have a generator input like the Sunsynk / Deye does.

It has (as you will be aware) an AC-grid input, but that is for grid tied operation. When that is present the Solis will attempt to synchronise with the AC-grid input frequency and voltage and then export power (i.e. increase the voltage on that connection) to power the loads and, if there are no loads will increase voltage to export to the grid.

I'm guessing a bit here... but IMHO, without an infinite load to dump its output to (i.e. the national grid), the Solis would keep upping its voltage until it trips, probably damaging your generator in the process

 

[SeaGal]

After I wrote that I thought I've been down that avenue before...

Hence see this thread and posting by @timselectric who know as much as anyone on here

Help Please. SolarEdge Inverter - Off Grid Solution

HI all I am Dave and I live in Spain. I have just had a brand new three phase solar edge system put in. However to my surprise they failed to mention to me that this inverter SE10K-RWS48BEN4 is not capable of going off grid. I have 16Kw of battery and I recently purchased an ID BUZZ so I was...

diysolarforum.com

 

[davidwellan]

Hi SeaGal, thank you so much for responding so quickly to my post and apoligies for my late reply, but we are flat out with our passive / off-grid house build at the moment and I've been struggling to find time.

It is very disappointing that there is no way to charge the batteries from my generator!

I was looking through the menus and found the following, there seems to be an option to select the current direction, either: Discharge or Charge. It is set for Discharge whilst we're running in Off-Grid mode.

Do you think it is too simplistic that if I set it in Charge mode, it would charge??!!

 

[SeaGal]

Do you think it is too simplistic that if I set it in Charge mode, it would charge??!!

Not 100% sure, but I think that is just showing the direction of supply from battery, real time.

Battery will both charge and discharge depending on PV input and house load.

Unfortunately, there is no charge port on the Solis RHI or EH1P, just the grid-tie AC grid connection.

 

[davidwellan]

Not 100% sure, but I think that is just showing the direction of supply from battery, real time.

Battery will both charge and discharge depending on PV input and house load.

Unfortunately, there is no charge port on the Solis RHI or EH1P, just the grid-tie AC grid connection.

Thanks.

How do you rate your SunSynk Inverter? Is it a worthy replacement for a Solis?

 

[profesor79]

What kind of generator you have? it is inverter generator or with voltage stabiizer? i am asking as I was told to not connect a normal generator to inverter as that can do havoc do to frequency synchronisation (but I was told that after I blow up my inverter...).
What I am doing now is connecting my generator over a full-bridge recitfier and 20k microfarads condensators to PV input, and the inverter is happy to charge my battery using this backdoor entry.

 

[davidwellan]

What kind of generator you have? it is inverter generator or with voltage stabiizer? i am asking as I was told to not connect a normal generator to inverter as that can do havoc do to frequency synchronisation (but I was told that after I blow up my inverter...).
What I am doing now is connecting my generator over a full-bridge recitfier and 20k microfarads condensators to PV input, and the inverter is happy to charge my battery using this backdoor entry.

That is a fantastic idea! I am not an electrician and don't fully understand how to do this, but I understand the principle. How much 'power' does that send to the PV input in terms of amps, volts and watts? My generator is 3.5 KW max output - https://www.championpowerequipment....tt-lpg-dual-fuel-inverter-generator-73001i-df
I'd love to understand how you do this.

 

[profesor79]

When running my generator over PV, I am adjusting max battery charge current to 30 amps (my cable is about 40meters long) and I converted my 2.5kW generator to use propane instead of petrol.

 

[profesor79]

so as you have 3k generator, let say that you could run it at 2k constant, which gives 2000W / 230V around 10 amps, and after the grtz bridge we will get 340VoC DC - so please check with your inverter if it can eat those values.

 

[SeaGal]

Thanks.

How do you rate your SunSynk Inverter? Is it a worthy replacement for a Solis?

Well I don't remember buying a SunSynk I have two Solis inverters.

 

[SeaGal]

That is a fantastic idea!

Really? Not sure the Solis's MPPT trackers would think the same...

This thread may be of interest...

Feed constant voltage DC into the input of a MPPT controller?

Is it safe to do this? Stay below the max voltage of course. Basically I would run mains through a variac, drop voltage to something sensible, rectify and filter it then feed the controller. This is a temp setup, I just want to use one to charge a battery, and to also test it out indoors...

diysolarforum.com

 

[profesor79]

btw @davidwellan did you try to connect you generator to home network bypassing the inverter?
in your case I will suggest buyng a charger or change inverter as you are off-grid.

 

[davidwellan]

Well I don't remember buying a SunSynk I have two Solis inverters.

Ah, I see... I just got the impression you did have one as you mentioned it in your original reply.

 

[davidwellan]

btw @davidwellan did you try to connect you generator to home network bypassing the inverter?
in your case I will suggest buyng a charger or change inverter as you are off-grid.

Yes, I think you're probably right and it is the safest bet. Thank you.

Any suggestions for decent chargers?