Using an inverter generator to charge the inverter battery during prolonged grid outage and no sun

[purrr]

With the recent storms the grid was out for many days and there was basically no sun (I don’t have panels yet but in any case there was no sun so it would not have helped).

My battery only lasted a day so we were without power for a few days.

I decided to a get 2,000W inverter generator to top up the inverter battery and supply some power to the house during such conditions.

I have a Solis 5kW inverter (model S6-EH1P5K-L-PRO) and a Sunsynk 5kWh battery (model SUN-BATT-5.32 with serial number starting with SSLR so a rebranded Eenovance).

An electrician will install a change over switch so when the grid is down I can connect the generator safely to the AC supply.

I have a few questions:

1. If the battery is partially charged and we’re on generator, when I boil a kettle will the inverter blend battery and generator power to supply the load? Kettle can draw more than the inverter generator.

2. What settings should I change in the Solis app. The most obvious is the max battery charge rate. Currently it is set to the nominal 50A (max is 100A). If the battery is 50V and I want to charge at 500W then I need to set it to 10A, correct? That leaves 1,500W spare for the house, correct?

3. Will the inverter automatically know what the generator can output?

The inverter generator: https://www.takealot.com/steco-sg-2050i-steco-inverter-generator-2000w/PLID94464184

Am I on the right track or do I need something more complicated than a change over switch?

 

[Lupus]

Firstly you can't use all 2000w of your generator you'll kill it. Recommended is 80%

 

[1am7h30n3]

It looks like your inverter has a GEN port, so you could get the electrician to wire it up to the generator input port instead of using a changeover switch to feed the generator into the GRID port.

Whichever port you choose, GEN or GRID, there's a setting for peak shaving (on grid), or gen power (on gen). That's an overall limit of how much power the inverter can pull from those ports, you could set it to perhaps 1500W. So yes if you are charging the battery at 500W and start up your 2000W kettle (2500W load) then the inverter will limit the power taken from the generator to 1500W and the remaining 500W to power the kettle will come from battery discharge.

The inverter won't automatically know how much power the generator can supply, no, you have to set it up. I would set the battery charging current to give you whatever load you feel comfortable running the generator at (say 50-80% continuous) accounting for the battery charging and the base load in your house (and inefficiencies).

 

[Fcon_Vpro]

With the recent storms the grid was out for many days and there was basically no sun (I don’t have panels yet but in any case there was no sun so it would not have helped).

My battery only lasted a day so we were without power for a few days.

I decided to a get 2,000W inverter generator to top up the inverter battery and supply some power to the house during such conditions.

I have a Solis 5kW inverter (model S6-EH1P5K-L-PRO) and a Sunsynk 5kWh battery (model SUN-BATT-5.32 with serial number starting with SSLR so a rebranded Eenovance).

An electrician will install a change over switch so when the grid is down I can connect the generator safely to the AC supply.

I have a few questions:

1. If the battery is partially charged and we’re on generator, when I boil a kettle will the inverter blend battery and generator power to supply the load? Kettle can draw more than the inverter generator.

2. What settings should I change in the Solis app. The most obvious is the max battery charge rate. Currently it is set to the nominal 50A (max is 100A). If the battery is 50V and I want to charge at 500W then I need to set it to 10A, correct? That leaves 1,500W spare for the house, correct?

3. Will the inverter automatically know what the generator can output?

The inverter generator: https://www.takealot.com/steco-sg-2050i-steco-inverter-generator-2000w/PLID94464184

Am I on the right track or do I need something more complicated than a change over switch?

1. Yes, as long as you arent exceeding your inverting capacity and your battery can output that amount of power draw

2 and 3. You will need to update peak power shaving setting or a max grid power setting. Im not super familiar with solis specifically but inverters wont have a way of knowing what is safe to pull without you telling them what's available. They should have some form of grid profile.
What you said about battery charge rate doesnt matter because its just a max setting and not a continuous charge setting. So if you have no solar and you told the inverter your grid is only 1600w (80% of 2000w), it will only ever charge at 1600w less your base load.

To be honest, I think your grid changeover switch idea isn't the best option, especially for the type of inverter you have. Your inverter has a specific and separate generator input which is designed to handle backup situations when your grid goes offline. If your generator was super fancy then the inverter could even tell the generator to power on automatically because the grid is offline. Research the generator input on your inverter

 

[cpu.]

Buy a camp gas stove from Checkers (or wherever) to boil water etc.

 

[SauRoNZA]

Wouldn’t make sense to limit your battery to 500W and have your generator pumping away at 2000W that isn’t being used.

The Solus will take care of what goes to the house and what goes to the battery dynamically so set this as high as is allowed.

Besides your settings may not even matter if there is a BMS involved and it’s in lithium mode as they usually do their own thing.

 

[purrr]

Thanks for the replies, I did not know the Solis has a generator port, this seems like the best way to go. Will investigate that…