EG4 battery to growatt 12k to power whole house

[willshakespeare]

Sorry to ask but have tried to find answer to this everywhere - building a system to power my house on battery (no solar)
Have free nights plan for 8pm - 6am
Use battery 6 am - 8 pm & charge batteries at night

Two systems:
No. 1
6 eg4 lifepo4 batteries (30k)
Growatt 12k inverter
This will directly power 1st main breaker panel - has 3 AC units - two 5 ton and one 3 ton ac
These are the main loads, others like pool pump/ev I’ll mainly use at night

No.2
Similar battery + inverter
Will power 2nd main breaker panel - 3 furnace blowers, 3 refrigerators, heavy media, surveillance camera

I’ve monitored yearly usage and am approximating 100kw per 24hours and likely 60kw in daytime

Don’t plan to go completely off grid as that would be a red flag - hoping to drain batteries to 20% before grid goes on

Questions and these will be super helpful as I’m an absolute amateur -
1. Will the setup start the AC units or should I look for a bigger inverter like sunsolar 18kw ?
2. Should I go for parallel inverters to power up the ac ?
3. Any other setup is recommended for an amateur ?

Obviously I’ll be hiring an electrician for the grid wiring , fuses etc. with this model I’ve got a break even abt 6 years with battery life of 15+

Thank you so much

 

[Darren67-72]

Here, I'll start....
Good idea, two 5 ton and a 3 ton a/c units is a lot of juice. I'd think a amp draw determination is in order. But, you may consider a "stackable" unit ( like a GS 12,000 *not UL*) and you may consider a UL unit due to the permitted installation (my assumption).
I like the split system, unfortunately the split is not better balanced.
Lastly, make sure the unit(s) you choose have 'time of use' settings. I don't think Growatt (non UL) have any.

 

[CrazyWabbit]

Technically since system could backfeed grid the utility needs to approve the system. Good luck.
Just go solar!

 

[Grimmster]

Would love to see your ROI calculations, could be useful for others that might want to do the same thing.

Before dropping a few grand on an inverter (let alone everything else) I would double check the specs on your A/C units, especially the startup surge. Maybe buy/borrow/rent a good clamp meter than can measure in rush current.

 

[Grimmster]

Yeah, as mentioned, how are you planning on controlling the schedule and switching back and forth? That is some high end functionality. You just going to manually throw the main breakers twice a day?

 

[629658]

The Sol Ark products will manage the TOU functions.

 

[willshakespeare]

Thank you all for the feedback - still researching and planning
Definitely installing microair soft starters to bring down lra on the ac units
Also likely going for solark 15k as it has 220 ac pass through and well equipped

ROI with batteries abt 7.5 years
If I add solar 11kw system about 6.5 years

Will keep everyone posted - won’t do complete diy as don’t have enough knowledge and experience

 

[kromc5]

If the 5ton and 3ton were on at the same time that would be all the load I would put on it. The batteries will deplete quickly and the voltage drop will be quick as well. I have really pushed the 12kw for testing but anything over 10kw for several hours and it does heat up. The 12kw easily started a 5ton but, if they could be running all of them then you would need a stackable inverters.

 

[629658]

My 15k starts our 4 ton geo without issue. No dimming at all. It came with a soft start factory installed. The soft start went out a month ago and they bypassed it until the replacement arrived. We never noticed a difference. Well pump is never an issue. 1.5 hp. at 350 ft. Pool works fine also.

 

[CarlCruzin]

Sorry to ask but have tried to find answer to this everywhere - building a system to power my house on battery (no solar)
Have free nights plan for 8pm - 6am
Use battery 6 am - 8 pm & charge batteries at night

Two systems:
No. 1
6 eg4 lifepo4 batteries (30k)
Growatt 12k inverter
This will directly power 1st main breaker panel - has 3 AC units - two 5 ton and one 3 ton ac
These are the main loads, others like pool pump/ev I’ll mainly use at night

No.2
Similar battery + inverter
Will power 2nd main breaker panel - 3 furnace blowers, 3 refrigerators, heavy media, surveillance camera

I’ve monitored yearly usage and am approximating 100kw per 24hours and likely 60kw in daytime

Don’t plan to go completely off grid as that would be a red flag - hoping to drain batteries to 20% before grid goes on

Questions and these will be super helpful as I’m an absolute amateur -
1. Will the setup start the AC units or should I look for a bigger inverter like sunsolar 18kw ?
2. Should I go for parallel inverters to power up the ac ?
3. Any other setup is recommended for an amateur ?

Obviously I’ll be hiring an electrician for the grid wiring , fuses etc. with this model I’ve got a break even abt 6 years with battery life of 15+

Thank you so much

What is a "free nights plan"? Are we talking cell phone minutes or electrical service?

 

[DIYrich]

What is a "free nights plan"? Are we talking cell phone minutes or electrical service?

Time of use where the GENERATION portion is free at night.

Understanding Free Nights Electricity Plans | Chariot Energy

Free electricity sounds amazing, but is it really? We answer your questions about free nights and weekends electricity plans and if they’re worth it.

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