night charging problem

[murphyjax]

I have a pretty specific case for a system I am planing. The electricity price is roughly 0.45USD by kwh here during the day, and goes down in the night to 0.01USD.
So the usual solar system wouldnt work with AC charge timers. Also the charge timer has to be adjusted manually every day at 12:00 when the electricity prices of the following day at every hour is published. So i would set it up to charge batteries always between 0:00 - 6:00 at night, with the option to change those times in case.

Is there any inverter/charger combo that could do that? going the growatt route it wouldnt be possible. unless i install a programmable AC switch - giving the growatt only at specific hours the AC current to be able to grid recharge batteries. which can be risky if the weather is really shabby for a while or during winter. thinking a 400ah battery charging with 50amps, needs 8 hours, not 6. so it wouldnt be able to fix an almost 0 sun production day during night charging.

 

[timselectric]

Many AIO's have TOS (time of use) settings. For charging from the grid during lower rate times.
My Growatt SPF-5000-ES has it, I'm not sure about other models. Look for "utility charging time" , the settings.

 

[murphyjax]

but the question is how hard is it to program that daily? the interface, can you tell me more on that for the growat you have?

 

[murphyjax]

i mean can you do it via wifi via software or is growatt owny programmable on the unit through buttons navigating menus?

 

[timselectric]

You set what time to start and stop charging.
Not sure if it can be done from the growatt app.
I'm not using their app. I'm using Solar Assistant for remote monitoring and control. You can setup time of day with SOC parameters on Solar Assistant, but I haven't played with it. If I find some time to play with it, I'll report back. But, it might not be anytime soon.

 

[murphyjax]

thanks for the answers, i really apreciate it. ive got one last thing. the growatt 5000 can charge to up to 80A. and they state in the manual "80Amp(@VI/P=230Vac)". which is confusing. cause who has a 80amp home connection. shouldnt it be 80A with the 48V which is eqal 17.x amp with 220v? trying to figure out how long it takes to charge with a single phase 15A for a 400AH battery with growatts system...

 

[timselectric]

Yes, it's 80a at the battery.
About 22a at 230V.
It would take about 5 hrs.

 

[fromport]

thanks for the answers, i really apreciate it. ive got one last thing. the growatt 5000 can charge to up to 80A. and they state in the manual "80Amp(@VI/P=230Vac)". which is confusing. cause who has a 80amp home connection. shouldnt it be 80A with the 48V which is eqal 17.x amp with 220v? trying to figure out how long it takes to charge with a single phase 15A for a 400AH battery with growatts system...

Since a lot of versions of the same kind of inverter is out there, download the midnite solar DIY manual at https://www.midnitesolar.com/pdfs/10-539-1_MN5048DIY_Manual_9-1-21.pdf

After quickly going over it, i think it has corrected a lot of the errors of the other manuals ;-)

 

[timselectric]

Also, with only a 15a circuit. You will have to set the charging rate lower, to avoid tripping the breaker/fuse. And, it could take 6 or more hours to charge batteries.

 

[murphyjax]

cool that helped a lot in the planing to fill these voids with some knowledge! thanks guys!