Is The Inverter Charger Necessary On A RV

[AfterShock]

I've done a build on my previous RV with 600W solar, PWN charger, 4 x 6V lead acid batteries and a standard 1000W pure sine inverter.

Now that I've purchased a longer term RV trailer, I'd like to set it up the best way possible. That being said, I can't seem to find out what the best set up is. I do have a few questions.

1. Is it worth it to install an Inverter / Charger directly to the panel that can switch from shore power to solar? They seem to be 3 to 5 times the price of a regular Puresine inverter. What I've done in the past is simply plug in the shore power cable into the inverter and had no issues. I am looking at running 2000 or 3000 W this time.

2. I've purchased 2 large LifePO4 12V 200Ah for a total of 400Ah. Should I run that in series or parallel? If I were to run it in series at 24V, what do I need to do for the trailer to run on 12V when not plugged into the inverter?

3. I do not usually camp where shore power is available, and the trailer sits in storage as it is too big for my driveway. I essentially have to rely on the solar system to recharge the batteries between uses. Are there any dangers to leaving the system unattended for long periods of time and what can I do to mitigate them? Is a good MPPT controller sufficient?

 

[Supervstech]

Inverter chargers are more expensive than pure sine inverters? I wasn’t aware of his.

All transformer based inverters would be more expensive than Hf inductor rail types... but the transformer gives huge surge capabilities the HF units do not have...

 

[John Frum]

I've done a build on my previous RV with 600W solar, PWN charger, 4 x 6V lead acid batteries and a standard 1000W pure sine inverter.

Now that I've purchased a longer term RV trailer, I'd like to set it up the best way possible. That being said, I can't seem to find out what the best set up is. I do have a few questions.

1. Is it worth it to install an Inverter / Charger directly to the panel that can switch from shore power to solar? They seem to be 3 to 5 times the price of a regular Puresine inverter. What I've done in the past is simply plug in the shore power cable into the inverter and had no issues. I am looking at running 2000 or 3000 W this time.

If you plan to connect to shore power an ul-458 inverter charger is the way to go.
It includes an automatic transfer switch which makes it a sweet setup.
If you prices an inverter and a charger and an automatic transfer switch you will see the value proposition.
The other huge advantage of an inverter charger is they are way more configurable for charge profiles and low voltage disconnect and much more.

2. I've purchased 2 large LifePO4 12V 200Ah for a total of 400Ah. Should I run that in series or parallel? If I were to run it in series at 24V, what do I need to do for the trailer to run on 12V when not plugged into the inverter?

Depends...
Do you have pure dc loads?
Will your batteries support being joined serially?
What is the continuos rating in amps of your bms?

3. I do not usually camp where shore power is available, and the trailer sits in storage as it is too big for my driveway. I essentially have to rely on the solar system to recharge the batteries between uses. Are there any dangers to leaving the system unattended for long periods of time and what can I do to mitigate them? Is a good MPPT controller sufficient?

Yes if your panels don't get enough sun you could run the battery down until the bms disconnects.
Your battery will still discharge after the bms disconnects albeit rather slowly.
You could damage your batteries.

 

[John Frum]

A 2000 watt high frequency inverter is doable at 12 volts
A 2000 watt low frequency inverter is pushing it at 12 volts
A 3000 watt high frequency inverter is really pushing it at 12 volts
A 3000 watt low frequency inverter is really really pushing it at 12 volts

 

[AfterShock]

If you plan to connect to shore power an ul-458 inverter charger is the way to go.
It includes an automatic transfer switch which makes it a sweet setup.
If you prices an inverter and a charger and an automatic transfer switch you will see the value proposition.
The other huge advantage of an inverter charger is they are way more configurable for charge profiles and low voltage disconnect and much more.



Depends...
Do you have pure dc loads?
Will your batteries support being joined serially?
What is the continuos rating in amps of your bms?


Yes if your panels don't get enough sun you could run the battery down until the bms disconnects.
Your battery will still discharge after the bms disconnects albeit rather slowly.
You could damage your batteries.

So I was somewhat on the right track, the Renogy 3000 Inverter / charger is the unit I was looking at:

3000W 12V Pure Sine Wave Inverter Charger w/ LCD Display

Renogy 3000W pure sine wave inverter charger not only acts as a DC to AC converter but also charge and maintain a battery bank. Compatible with various batteries.

ca.renogy.com

That being said, this is a 3000W unit, I couldn't tell if this unit is low or high frequency (how can you tell?). According to SmoothJoe I'd be pushing it at 12V.

What you're saying is my batteries may not support being joined serially. This is news to me as I am used to "dumb" led acid batteries. I purchased the batteries on Amazon: https://www.amazon.ca/gp/product/B08KZQBMSL/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
There is limited information on the capability...

As far as the batteries running down, I was more worried about the opposite effect. There is plenty of sun here, so can the batteries get damaged if they're constantly being charged and full or is a good mppt controller completely mitigating that aspect. Otherwise, I can put them on a maintainer over the winter for storage while not connected to the solar system.

 

[AfterShock]

Or do I simply go with the 2000W model, run everything on 12V and life is good.

 

[Supervstech]

Depends on your loads.
2000 W Hf like that one isn’t good for surge loads.

 

[Bud Martin]

So I was somewhat on the right track, the Renogy 3000 Inverter / charger is the unit I was looking at:

3000W 12V Pure Sine Wave Inverter Charger w/ LCD Display

Renogy 3000W pure sine wave inverter charger not only acts as a DC to AC converter but also charge and maintain a battery bank. Compatible with various batteries.

ca.renogy.com

That being said, this is a 3000W unit, I couldn't tell if this unit is low or high frequency (how can you tell?). According to SmoothJoe I'd be pushing it at 12V.

What you're saying is my batteries may not support being joined serially. This is news to me as I am used to "dumb" led acid batteries. I purchased the batteries on Amazon: https://www.amazon.ca/gp/product/B08KZQBMSL/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
There is limited information on the capability...

As far as the batteries running down, I was more worried about the opposite effect. There is plenty of sun here, so can the batteries get damaged if they're constantly being charged and full or is a good mppt controller completely mitigating that aspect. Otherwise, I can put them on a maintainer over the winter for storage while not connected to the solar system.

At 63 lbs weight, it is LF inverter type, the HF one weight in <20 lbs.
Surge is also 3 times the rated power: Surge Power (1 second): 9000W

 

[John Frum]

So I was somewhat on the right track, the Renogy 3000 Inverter / charger is the unit I was looking at:

3000W 12V Pure Sine Wave Inverter Charger w/ LCD Display

Renogy 3000W pure sine wave inverter charger not only acts as a DC to AC converter but also charge and maintain a battery bank. Compatible with various batteries.

ca.renogy.com

That being said, this is a 3000W unit, I couldn't tell if this unit is low or high frequency (how can you tell?). According to SmoothJoe I'd be pushing it at 12V.

A 3000 watt low frequency inverter is really really pushing it at 12 volts

As far as the batteries running down, I was more worried about the opposite effect. There is plenty of sun here, so can the batteries get damaged if they're constantly being charged and full or is a good mppt controller completely mitigating that aspect. Otherwise, I can put them on a maintainer over the winter for storage while not connected to the solar system.

Lifepo4 batteries like to be cycled.
Its unnecessary wear and tear to charge them full and store them
Its even worse to leave them exposed to charge voltage after they are full.
Probably best to charge them to storage voltage of 3.3 volts per cell or 13.2 for the battery and then check them every 2 or 3 months. Re-charge to storage voltage if necessary.

As now for the math.
3000 ac watts * 1.5 low frequency fudge factor / 12 volts low cutoff = 375 dc amps
375 dc amps / .8 fuse headroom = 468.75 fuse amps

2000 ac watts * 1.5 low frequency fudge factor / 12 volts low cutoff = 250 dc amps
250 dc amps / .8 fuse headroom = 312.5 fuse amps

 

[Supervstech]

At 63 lbs weight, it is LF inverter type, the HF one weight in <20 lbs.
Surge is also 3 times the rated power: Surge Power (1 second): 9000W

I’m not so sure... the specs do not show surge current duration, and they specify 3 legs of 40A input, that is usually HF...

 

[AfterShock]

Looking at the fly power website, there is zero information on the bms. This is not surprising since almost any Lifepo4 batteries currently sold in Canada come from China. We do not have the option of buying Battle Born batteries like in the U.S.

On that note, it's probably preferable that I stay at 12V unless someone here that is smarter than me can confirm that I can put these batteries in series.

It's probably also preferable that I use a 2000W inverter like this one if I am to stay at 12V:

2000W 12V Pure Sine Wave Inverter Charger w/ LCD Display

Renogy 2000W pure sine wave inverter charger not only acts as a DC to AC converter but also charge and maintain a battery bank. Compatible with various batteries.

ca.renogy.com

The output frequency says this: Output Frequency (Nominal): 50/60 Hz

Does that mean anything? I am still unsure if this is HF of LF.

Any suggestions on a reliable MPPT controller that would work for my set up and about 500W of panels in series?

 

[Bud Martin]

Looking at the fly power website, there is zero information on the bms. This is not surprising since almost any Lifepo4 batteries currently sold in Canada come from China. We do not have the option of buying Battle Born batteries like in the U.S.

On that note, it's probably preferable that I stay at 12V unless someone here that is smarter than me can confirm that I can put these batteries in series.

It's probably also preferable that I use a 2000W inverter like this one if I am to stay at 12V:

2000W 12V Pure Sine Wave Inverter Charger w/ LCD Display

Renogy 2000W pure sine wave inverter charger not only acts as a DC to AC converter but also charge and maintain a battery bank. Compatible with various batteries.

ca.renogy.com

The output frequency says this: Output Frequency (Nominal): 50/60 Hz

Does that mean anything? I am still unsure if this is HF of LF.

Any suggestions on a reliable MPPT controller that would work for my set up and about 500W of panels in series?

That is the AC line frequency, not the switching frequency for converting DC to AC. You can ask Renogy question about their products, just make sure to talk to some one at Renogy that actually knows what they are selling, not from some one that reads the script.

 

[Zwy]

I've done a build on my previous RV with 600W solar, PWN charger, 4 x 6V lead acid batteries and a standard 1000W pure sine inverter.

Now that I've purchased a longer term RV trailer, I'd like to set it up the best way possible. That being said, I can't seem to find out what the best set up is. I do have a few questions.

1. Is it worth it to install an Inverter / Charger directly to the panel that can switch from shore power to solar? They seem to be 3 to 5 times the price of a regular Puresine inverter. What I've done in the past is simply plug in the shore power cable into the inverter and had no issues. I am looking at running 2000 or 3000 W this time.

Did you look at Growatt or MPP Solar? Automatic transfer switch. And yes, the transfer switch will automatically switch grounding to shore power if you plug in and draw off shore power. It will automatically ground to inverter if running off battery power.

2. I've purchased 2 large LifePO4 12V 200Ah for a total of 400Ah. Should I run that in series or parallel? If I were to run it in series at 24V, what do I need to do for the trailer to run on 12V when not plugged into the inverter?

A buck converter gets you the step down from 24v to 12v. I have one that is 720 watts, that's 60 amps on 12v. 24v is really the way to go once you start getting over 2000 watt inverters.

3. I do not usually camp where shore power is available, and the trailer sits in storage as it is too big for my driveway. I essentially have to rely on the solar system to recharge the batteries between uses. Are there any dangers to leaving the system unattended for long periods of time and what can I do to mitigate them? Is a good MPPT controller sufficient?

I'd have the ability to quickly change charger settings to lower SOC to 50 to 70% if extended time frames. One thing you will need to consider is cold weather if you have a climate below 32F or 0C. If so, you would probably want a heater system for the LFP bank.

 

[time2roll]

1) solar is always working so there is never really a switch over from plugging in or not. I often don't even plug in unless I need A/C. I prefer separate components. You already have a converter that might work fine to keep the battery up. Just a stand alone inverter is fine. Add a separate transfer switch if you get bored dragging the cord out to plug in.

2) If you go 24 volts on the battery you are far better to build a 24v battery with single BMS to keep the series cells in balance. You will need a 24-12 converter to run your 12v accessories.

3). LFP batteries can probably just be disconnected. Verify your MPPT controller allows you to adjust the voltage for best results.

 

[John Frum]

You can ask Renogy question about their products, just make sure to talk to some one at Renogy that actually knows what they are selling, not from some one that reads the script.

Good luck with that

 

[Bud Martin]

Good luck with that

Yeah I know, their customer service has gone downhill.

 

[Boondock Saint]

Yeah I know, their customer service has gone downhill.

*Bang head here*

 

[AfterShock]

I did a bit more research tonight about the 12vs24 conundrum. I did find that the batteries I’ve purchased can be used in series so I could technically use them at 24V.

that being said, it seems like even in the 2000W and 3000W inverter / charger category, not many units can even take 24V. Renogy offers no 24V option at all. The Victron multi-plus, which seems to be the unit of choice for YouTubers, also comes in 12V models for 2000W and 3000W although they do offer the 24V as well.

Does that mean it’ll work fine on 12V? Why would these manufacturers offers products that wouldn’t work properly at that voltage?

I also just looked at the growatt 3000W 24V since it’s been mentioned. It does have the mppt unit built in which is nice.

Right now based on availability of the products here in Canada, I would be leaning towards building one of following 2 options:

Renogy 2000W 12V inverter / charger
Renogy 40 mppt solar charger
Renogy 500A battery monitor
batteries Set up in parallel for 400ah @ 12V
cost around $1100 CAD ~ $850 USD ish

or

Growatt 3000W 24V solar inverter charger
Built in 80A mppt
Renogy 500A battery monitor
Batteries in series for 200ah @ 24V
Buck converter for 12V system
Cost around $1500 CAD ~

other systems like Victron appear to be about double the cost.

which one is best?

 

[chrisski]

A buck converter gets you the step down from 24v to 12v. I have one that is 720 watts, that's 60 amps on 12v. 24v is really the way to go once you start getting over 2000 watt inverters.

The biggest load for me to plan for is leveling jacks. This is one of the reasons I have stayed at 12 volts.

I had not seen a buck converter before That could handle that power. I did just find one I had missed. The Orion 24 volt to 12 volt DC to DC converter handles 70 amps, and for me, that will probably be good. The device weighs about 2 LBS.

My 12 volt loads would be most of what I use. What uses the most energy is the Propane Blower motor, up to 100 ah a night on the coldest night of the year with the heater blowing nearly all night. That is only 6 amps though.

The largest amperage I see are the leveling jacks. I have seen 50 amps, and others have seen 100 amps. If 50 amps is really my upper limit, than I should be fine. The fuses on the leveling jacks are four 50 amp fuses.

 

[John Frum]

which one is best?

I asked earlier about your pure dc loads.
That is a factor in the 12volt vs 24 volt decision.
Before you spend money you should do an energy audit to make sure you have sized your system to your needs.
See my signature for a helpful link.