Growatt SPF 3000TL LVM - 24v - 8 * 280Ah LiFePo4 - Ventilation (?) - RV Specific Question

[monoxyde]

Preamble:

I've been slowly collecting the materials for my RV off grid System.

I ordered a GroWatt SPF 3000TL LVM back in June and received it promptly.

I ordered an Overkill Solar 8s 24v BMS, and received it within a few weeks.

I ordered 8 LiFePo4 cells from China, and waited 95+ days for delivery, but they arrived, and I've been able to top balance 4 of them, and now I'm waiting for the last 4 to top balance.

Getting to the point:

I've only seen 1 or 2 threads posted where people do this.... but, because of my travel trailer, I think it's going to be the easiest for me. I'm thinking about mounting my Growatt either in the pass through space (on it's side), or underneath the bed storage inside the cabin, which is where I'll put my batteries. I'm not going to wire it into my trailer, but instead I'm going to have a TT-30 A/C input/output coming from the Growatt, and I'll just open up the pass-through space and "plug my camper into itself" when I need off grid power.

The point:

With the LiFePo4 batteries, I know I don't need any/much ventilation. They should be protected from the majority of the elements secured inside the camper.

As for the Growatt, what kind of ventilation does it need? Will it survive inside the passthrough?

Will the Growatt survive under the bed, in the limited space that is there? It'll be a shorter cable run (but not by much) to the batteries, but how hot will it get? How much ventilation does it need?

Does anyone have any answers to these questions?

 

[monoxyde]

Side note, I read the operating temperature of the Growatt was 55c, which is about 130F.

Even if it's under the bed, I don't think there is any way whatsoever it can get that hot. I did speak with the boss, and maybe I can put an input/output DC fan on the bed, to at least "regulate" the temperature in that compartment, and get some airflow in there.

 

[Blazedoobies]

Side note, I read the operating temperature of the Growatt was 55c, which is about 130F.

Even if it's under the bed, I don't think there is any way whatsoever it can get that hot. I did speak with the boss, and maybe I can put an input/output DC fan on the bed, to at least "regulate" the temperature in that compartment, and get some airflow in there.

Use a fan because imagine how hot itll get in the compartment. Cells wont like that much heat. I was thinking about putting mine under the bed also but there wasnt enough height. Ive been thinking lately to put them in the front compartment but our bed is over the compartment and I am a little cautious to sleep over so much stored energy. Currently my set up is in the back of the camper in the spare bedroom. We have a 30 ft 5th wheel.

 

[Zwy]

Preamble:

I've been slowly collecting the materials for my RV off grid System.

I ordered a GroWatt SPF 3000TL LVM back in June and received it promptly.

I ordered an Overkill Solar 8s 24v BMS, and received it within a few weeks.

I ordered 8 LiFePo4 cells from China, and waited 95+ days for delivery, but they arrived, and I've been able to top balance 4 of them, and now I'm waiting for the last 4 to top balance.

Getting to the point:

I've only seen 1 or 2 threads posted where people do this.... but, because of my travel trailer, I think it's going to be the easiest for me. I'm thinking about mounting my Growatt either in the pass through space (on it's side), or underneath the bed storage inside the cabin, which is where I'll put my batteries. I'm not going to wire it into my trailer, but instead I'm going to have a TT-30 A/C input/output coming from the Growatt, and I'll just open up the pass-through space and "plug my camper into itself" when I need off grid power.

The point:

With the LiFePo4 batteries, I know I don't need any/much ventilation. They should be protected from the majority of the elements secured inside the camper.

As for the Growatt, what kind of ventilation does it need? Will it survive inside the passthrough?

Will the Growatt survive under the bed, in the limited space that is there? It'll be a shorter cable run (but not by much) to the batteries, but how hot will it get? How much ventilation does it need?

Does anyone have any answers to these questions?

I would not worry about the batteries concerning heat inside a compartment, you aren't charging or discharging anywhere near 1C in a TT. You do want an area where it helps to keep battery above freezing.

As for the GW, it will generate heat while charging and/or inverter on. I mounted mine in an exterior box shown in the photo below. I also added a fan and thermostat that will kick on the fan at 129F. I have the option to leave the door open. Thermometer probe is at the top of the GW as the fans internal to the GW blow upwards. Commonly see 115F when I open the door. Have never heard the box fan kick in yet. But I also haven't used it in 90F plus weather either.

 

[monoxyde]

So, I'm more of a visual person, and I'm trying to get all this put together.

Trying to build an Amazon shopping list, and check it twice.

At this time, I will not have an PV input on the Growatt, but as soon as I can get down to Santan Solar's warehouse, I will be adding that.

I did not include A/C Input on my drawing, just to keep it a bit cleaner, but I'm going to put a TT-30 input/output on the Growatt, and plug the trailer into it (and turn off the converter from the breakerbox inside the trailer, so there is no power loop).

Does this drawing look safe/practical?

 

[Zwy]

So, I'm more of a visual person, and I'm trying to get all this put together.

Trying to build an Amazon shopping list, and check it twice.

At this time, I will not have an PV input on the Growatt, but as soon as I can get down to Santan Solar's warehouse, I will be adding that.

I did not include A/C Input on my drawing, just to keep it a bit cleaner, but I'm going to put a TT-30 input/output on the Growatt, and plug the trailer into it (and turn off the converter from the breakerbox inside the trailer, so there is no power loop).

Does this drawing look safe/practical?

It will work as far as routing. You're planning on using 4 ga wire? The 250a fuse is too high for 4 ga wire. 4/0 for 250a. I used 1/0 wire and 150a fuse for cable from battery to inverter.

There is an transfer switch built into the GW, hardwire it and forget the TT-30.

 

[monoxyde]

It will work as far as routing. You're planning on using 4 ga wire? The 250a fuse is too high for 4 ga wire. 4/0 for 250a. I used 1/0 wire and 150a fuse for cable from battery to inverter.

There is an transfer switch built into the GW, hardwire it and forget the TT-30.

Not sure how/where I could cleanly hardwire it.

I've looked all over the trailer for storage ideas, and the best place I can come up with is under the bed.

If I mount to my existing TT-30 input, and output there, then I've got to figure out how to route a new thick cable to the batteries, that will likely be on the opposite end of the trailer.

 

[monoxyde]

So, maybe this is a dumb question, I'm still learning, and ready to start building though.

Trailer Input = 30Amp @ 120v

My batteries = 24v

I'm going into a 3000Watt inverter, and according to GroWatt manual, it says 24v @ 164amp MAX D/C input.
that is 3936 watts of power.

On the fuse size, 164*1.5=246 amps... so 250 Amp fuse.

Now, this is where I get confused.

Watts = Amp * Voltage.

Why his the amperage so much higher on the D/C input side of the Growatt than the A/C input side of the trailer? I would imagine a 40amp fuse would be needed on the A/C output side of the Growatt?

 

[Zwy]

Not sure how/where I could cleanly hardwire it.

When I did mine, I purchased a new detachable power cord and port to provide the AC input to the GW. Port is shown in this photo on left side.

In this photo, you can see the wires that run from the cord port to the GW.




You have the choice of buying a new cord/port or if your current one is detachable to simply install a new port close to the GW to shorten the distance. Not hard to install.


Why his the amperage so much higher on the D/C input side of the Growatt than the A/C input side of the trailer? I would imagine a 40amp fuse would be needed on the A/C output side of the Growatt?

The watts are higher because you are using a device designed to be used in stationary building such as a house. As for fusing requirements on the AC side, the GW has a breaker on the output built in and you run the output to your current AC panel which should have a breaker on it's input.

 

[acdoctor]

3000 watts / 20 volt low voltage limit = 150 amps x 1.1 (90% ) inverter performance = 165 amps. So that would be worse case scenario. I would not go 1.5 my self. With lfp I hope you set low voltage cut off higher so max amps will be lower.

 

[monoxyde]

3000 watts / 20 volt low voltage limit = 150 amps x 1.1 (90% ) inverter performance = 165 amps. So that would be worse case scenario. I would not go 1.5 my self. With lfp I hope you set low voltage cut off higher so max amps will be lower.

Okay, that makes sense to me.

I will be using Will's recommended settings which off the top of my head is 23.1 volts.

So 3000/23.1 = ~130 × 1.1 = ~143.

So I only need a 150 Amp fuse off my batteries?