Do you have to use an AC input on Growatt system?

[Pete in Puerto Rico]

Hello, I am preparing to install my 3k Growatt system. But I will only be able to connect the PV input to my batteries. The AC input with 40 AMP breaker will not be ready at the time of install. Questions:
1. Is an AC input required initially?
2. Will the Growatt system and batteries be ok with no load on the system yet?
3. Can I charge my 2 x 200 Amp lithium batteries with the Growatt system initially?

Any help would be appreciated. I live in Puerto Rico and want to be ready for hurricane season.

Thanks,

Pete

 

[Xhumeka]

Which specific model are you referring to? At any rate, you can almost certainly use the Growatt with no AC input - that's what these things are mostly designed for

 

[shot428]

3. Can I charge my 2 x 200 Amp lithium batteries with the Growatt system initially?

will require ac

 

[DThames]

Speaking of a Growatt 3000 (that I have).

Connect it to the battery and it will come on and you can make settings. Don't turn the Inverter switch on unless you want it to run down your battery. Even with no load, the inverter uses about 50-60watts. With just the battery connected, the display should turn off after 5-10 minutes. It will be okay in that state for a good long while. If you connect solar, it will charge off the solar. As soon as the solar voltage is there, the display will come back on and you can see what batter voltage is, charging current, etc. No AC needed if you can charge from solar.

 

[timselectric]

will require ac

Or solar charging.

 

[Pete in Puerto Rico]

Thank you for all the input I will be confident getting this system up and running.

 

[Pete in Puerto Rico]

Hey guys I have another issue/question: on my Growatt SPF 3000TL LVM, I was in the setup LCD Setting and on item number 19 charging voltage and number 20 float charge. When I set the specs, the float charges changes my charging voltage to the same number as the float. ? The charge voltage is 29.2 and the float is 27.6. The batteries are Ampere time, 12v 200Ah (200A BMS)

Any thoughts

 

[timselectric]

Hey guys I have another issue/question: on my Growatt SPF 3000TL LVM, I was in the setup LCD Setting and on item number 19 charging voltage and number 20 float charge. When I set the specs, the float charges changes my charging voltage to the same number as the float. ? The charge voltage is 29.2 and the float is 27.6. The batteries are Ampere time, 12v 200Ah (200A BMS)

Any thoughts

If you are using battery communications (or set to LI or user2), you can't change those settings. They are controlled by the BMS.

 

[Pete in Puerto Rico]

If you are using battery communications (or set to LI or user2), you can't change those settings. They are controlled by the BMS.

The BMS does not connect to the Growatt, the BMS is inside the battery box only. I selected US2. That generally means I need to input those specs on 19,20,21

 

[Rho]

will require ac

I can charge my 48 v 200amh with just pv. I put on sbu then I don't use any ac power. All the pv power goes to batteries. This can take several days depending on soc of battery. The inverter 12,23,19 and 20 settings. I use us2 battery settings. Seems 13 is important. I am 56.8.
My bms is Daly so does not work with Growatt. I sat it up and it monitors the battery,preventing inverter from overcharging and it balances my lifepo4 16s battery. Glad I have it my growatt has tried on 2 occasions to overcharge to 60. Bms shut it down. All I can say is alot of patience is required to tweek and finally reach full soc on batteries. I suggest top balance it is very important before hooking up. Then monitor battery closely for runners. Really very important to get full charge. If possible charge 1 battery at a time,then tie together. Will speed up process,balancing 2 large batteries can be time consuming. Good luck.

 

[shot428]

I can charge my 48 v 200amh with just pv. I put on sbu then I don't use any ac power. All the pv power goes to batteries. This can take several days depending on soc of battery. The inverter 12,23,19 and 20 settings. I use us2 battery settings. Seems 13 is important. I am 56.8.
My bms is Daly so does not work with Growatt. I sat it up and it monitors the battery,preventing inverter from overcharging and it balances my lifepo4 16s battery. Glad I have it my growatt has tried on 2 occasions to overcharge to 60. Bms shut it down. All I can say is alot of patience is required to tweek and finally reach full soc on batteries. I suggest top balance it is very important before hooking up. Then monitor battery closely for runners. Really very important to get full charge. If possible charge 1 battery at a time,then tie together. Will speed up process,balancing 2 large batteries can be time consuming. Good luck.

My original post was based on the notion that I was told that the batt must be fully charged before turning the growatt on and that to this end I purchased a separate (AC) charger and I am not in a place where I can say whether that is proper or wrong ? But have seen several vids where they also charge the batt w/ a charger before hooking it up to use/test so what do I know LOL

 

[Rednecktek]

Best practice is to fully charge the batteries before you connect up any AIO and it's good practice IMO because there are about a dozen settings you're going to need to futz with to get it all set up and if your batteries are dead when you start "bad things" can happen. It buys you time to make sure you're getting everything working right before you put the system into service.

Fortunately it's easy to do if you're stringing a bunch of 12v batteries in series because any bog standard car battery charger can get a LFP battery to full-enough (95%+) to get everything up and going.

 

[Rho]

My original post was based on the notion that I was told that the batt must be fully charged before turning the growatt on and that to this end I purchased a separate (AC) charger and I am not in a place where I can say whether that is proper or wrong ? But have seen several vids where they also charge the batt w/ a charger before hooking it up to use/test so what do I know LOL

I have a adjustable charger on the way. Hoping to get soon. I learned hard way that you can charge being off grid. Lol took 3 days to do it. I do know now being fully charged and top balanced is a big plus. Lessons learned. I too am confronting hurricanes soon. I found keeping my inverter totally off grid is best. I do not have grid going to my inverter. I get much better safer results. If no pv power and battery at 49 v. I turn on grid. I use transfer switch to go to grid for my load. Leaving pv on to charge my battery. Seems to charge better in sbu or sub mode than solar. Just my observations. Seems each Growatt has it own quirks, reading post. Hope this helps.

 

[JWLV]

I have the exact same model Growatt that you are asking about.

You do not have to connect it to AC. You can if you want. For months I did not connect it to AC power until one day the entire thing shut down. It happened after a few days of cloudy and rainy weather. My batteries ran down and the Growatt shut down. Now I have it connected to AC so that it can recharge my batteries if solar power isn't sufficient. The priority setting is set to SBU -- Solar > Battery > Utility.

As for settings 19 & 20, they both change at the same time. If you change one, the other changes with it. For LiFePo4 batteries, you really don't need a separate float voltage. If the batteries need to charge, it'll charge. If the batteries don't need to charge, it won't charge. A different float voltage doesn't really do anything for it. I believe if you set the battery type of LI (or was it US1?), you can input different values for 19 & 20. My battery type is set to US2.

 

[Off Gridin' It]

Hello, I am preparing to install my 3k Growatt system. But I will only be able to connect the PV input to my batteries. The AC input with 40 AMP breaker will not be ready at the time of install. Questions:
1. Is an AC input required initially?
2. Will the Growatt system and batteries be ok with no load on the system yet?
3. Can I charge my 2 x 200 Amp lithium batteries with the Growatt system initially?

Any help would be appreciated. I live in Puerto Rico and want to be ready for hurricane season.

Thanks,

Pete

Im not sure if you got the answer you were looking for but here is the answers you the questions.

1. Is an AC input required initially?
No, it doesn't need to have any AC input to work. AC input can be shore/grid power or a generator.

2. Will the Growatt system and batteries be ok with no load on the system yet?
Yes if you connect the batteries to the growatt with no PV input or AC input it will be fine. The batteries will just not have any incoming voltage to charge without some kind of power coming in.

3. Can I charge my 2 x 200 Amp lithium batteries with the Growatt system initially?
Yes you can charge the LiFePO4 batteries. However as you said you have no AC or PV input so without some source they won't charge.

 

[schmism]

2. Will the Growatt system and batteries be ok with no load on the system yet?
Yes if you connect the batteries to the growatt with no PV input or AC input it will be fine. The batteries will just not have any incoming voltage to charge without some kind of power coming in.

To clarify as previously indicated, you must keep the inverter switch on the bottom in the off position in order not to drain the batteries from the inverter/SCC circuitry being powered on. There is more than one post of people who have done this - hooked up the unit, turned it on, left it and came back days/weeks/months later to find completely discharged batteries.

 

[Off Gridin' It]

To clarify as previously indicated, you must keep the inverter switch on the bottom in the off position in order not to drain the batteries from the inverter/SCC circuitry being powered on. There is more than one post of people who have done this - hooked up the unit, turned it on, left it and came back days/weeks/months later to find completely discharged batteries.

Yes that is right. If left on it will eventually drain the battery. So until there is some sort of PV or AC power connected just leave it off.

 

[Herb]

Hello, I am preparing to install my 3k Growatt system. But I will only be able to connect the PV input to my batteries. The AC input with 40 AMP breaker will not be ready at the time of install. Questions:
1. Is an AC input required initially?
2. Will the Growatt system and batteries be ok with no load on the system yet?
3. Can I charge my 2 x 200 Amp lithium batteries with the Growatt system initially?

Any help would be appreciated. I live in Puerto Rico and want to be ready for hurricane season.

Thanks,

Pete

Hola, No AC is required at all unless you need to charge batteries using the AC to DC charger. No load required either, the Growatt will wait patiently for a load to show up. But be aware the standby consumption on any of these all in one units is pretty high. It will deplete your battery if left on standby for a long time. There is a setting to put it in sleep mode that consumes less but I personally just turn it off when not in use. You can charge as many batteries as you like as long as you have solar power coming in or charge them with the AC to DC charger. The more capacity the batteries have the longer it will take. It takes me 3 days to charge my bank of 8 X 100ah batteries from solar but I do have a smaller solar array dedicated to the Growatt since I use only when needed. Buena suerte!

 

[Pete in Puerto Rico]

Thanks for your reply.