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Growatt SPF 3000 TL LVM ES without batteries

Dave (Boog)

New Member
Joined
May 18, 2020
Messages
132
Location
Colorado Springs
Hi,
Does anyone on the forum have this inverter? Has anyone tried it without batteries? This is one of the units that when used alone, not in parallel can supposedly work without external batteries.
My question is, without batteries does the unit draw power from the home AC? Can I test it without any batteries and without any Solar input?
Thanks
 
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Dave I am very interested in this very inverter. I just discovered it yesterday but I think it will fill my bill. I am interested as well in how it interacts with the grid power. I think it can be made to prioritize PV but supplement with grid without back feeding. Is this you understanding? Please let me know when you get yours. Thank you so much ahead of time.
 
Hi. Not sure. Mine just arrived yesterday. I haven’t unboxed it yet. But I’m pretty sure that you can charge batteries either from PV or from the grid. I’ll write more about my experience as time goes by.
I bought the 48v version. I was originally going with 24v but changed my mind, and am waiting for 8 more 272ah Lishen cells to arrive from China. I just placed the order this week, so it’ll be sometime in May before they get here.
I also have 24 250 watt solar panels to install. I’m going to start building my ground mount for the panels soon.
 
My questions concern its batteryless operation. Will you be doing any testing without batteries? Thanks again Dave.
 
I just ordered mine today. I will be using a full Chevy Volt battery pack at a lower 48v 12s config vs 14s
 
I set up my 24V Growatt today. All the videos and the manual says to hook up battery first so I did. I set Growatt to power saving mode (#4) and the inverter would not work. The fan that I tried to power would turn a couple times then nothing. I decided to disable the power saving mode and it worked. I have it hooked up to Evo 24v 120Ah. They have free shipping by freight on a pallet (75 pounds). Only took a week. I could track it too. I thought I should mention the power saving issue. I have not read about it. I may disable it in the future to see what happens. I do not plan on running it all the time.
 
Maybe try a heavier load. Fans tend to not take much.
Yea, I think you are right (fan draws 15 watts). I finally had the courage to plug it to AC and found I got AC power output. Then I disabled power saving mode (which is a default setting). Then inverter kicked in. So when the power saving mode is used, you need a decent load to trigger inverter. I was afraid to put a heavier load with it acting up.
 
How does this differ than many other all-in-one units that are available? Can any other all-in-one units NOT do this same thing?! e.g. Victron Easy Solar? Granted, I'd add a battery anyway to take up any surge, much like Will did with the GroWatt.


REPLY
 
I found that I cannot use the power saving mode with my Growatt. I do not have experience with any other.
 
Hi. Not sure. Mine just arrived yesterday. I haven’t unboxed it yet. But I’m pretty sure that you can charge batteries either from PV or from the grid. I’ll write more about my experience as time goes by.
I bought the 48v version. I was originally going with 24v but changed my mind, and am waiting for 8 more 272ah Lishen cells to arrive from China. I just placed the order this week, so it’ll be sometime in May before they get here.
I also have 24 250 watt solar panels to install. I’m going to start building my ground mount for the panels soon.
Hi, Did you order directly from watts247? Thank-you.
 
I bought this inverter. Here is what happened.

The first one I've received would turn on, then after a few seconds it would short out. It would either pop the panel breaker or the internal breaker and beep with an error code indicating there is something wrong with it. I've arranged a replacement with watts247. Ian was great, he sent me a replacement right away and sent me a shipping label to use for the return. The second one I've received seems to be functional, although, I have only tested it without hooking up batteries. I connected solar input, utility input and inverter output only.

There seems to be a bit of a problem with it. The watts247 store page (https://watts247.com/product/spf-3000tl-lvm-es/) nor the datasheet say anything about the minimum solar voltage the inverter will work at. When I hooked up ~140V solar array, the inverter would not use solar (no arrow from solar to inverter on the screen). When I hook up ONLY solar and no utility/no battery, the inverter does output ~110V AC (instead of 120V). The systems does start working, however, at about 160V solar input, according to my tests, however, it seems to work best at higher voltages. I have it at ~220V solar right now. Ian at watts247 has told me that my solar input voltage must be too low. I don't know if I buy that. The MPPT range is supposedly 120V-250V. May this problem be related to a defective unit or is this because I have no battery connected?
 
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I have been experimenting more and going without a battery is not great. I can make it work if the load required is resistive and small, but going without a battery puts unneeded stress on the circuits. If it is not able to support the load, you will have a good deal of current flowing before it trips. Then you will have to disconnect solar, which can also cause problems if done repeatedly. These circuits do better with a buffer. There are just too many constant potential fluctuations and trying to control it is very difficult.

Honestly just use a small battery. It will help a lot. You could use a very small lead acid battery and it would work great.
 
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