Generator + Battery Bank?

[Freelander]

Exactly, I'm looking to keep the 120v outlets live on a battery bank (quiet hours), and then top off batteries with the generator or shore power later.

So, it looks as if I'm going to need an automatic transfer switch unless I want to manually flip switches. It doesn't really matter to me, but I'd prefer not to think about it, and I know if it's not automatic and I backfeed the generator from the inverter, I'm not going to have a fun or safe time.

Which switches are you going to flipping all the time?

 

[ExploringOne]

Which switches are you going to flipping all the time?

I was referring to the transfer switch, if it's not automatic. I'm "comfortable enough" to be dangerous with electricity, but I know when to not mess with things. Maybe I should mention I also have 10 kW of solar on my house, and I've looked at what it would take to add a battery bank, and I'm not interested in the money/work it would require.

That being said, I'm no stranger to solar. I'm just a stranger when it comes with solar + batteries. This thread was meant to be about "generator + batteries" (I know it's a difference because AC vs DC output). The reason I wanted to tie Generator into the battery bank for replenishment, was because my generator was cheaper than the cost of 4 kW of solar panels in the short term (refueling long term though, will be expensive).

 

[Freelander]

I have Solar and a Generator, and they work just fine together without a transfer switch. I can use both at the same time.

 

[Freelander]

Does your Trailer have a Convertor in the Control Panel?

 

[Freelander]

I think I understand where you're coming from. I installed a standby generator at my house a few years ago, and installed an auto transfer switch to switch between Main line power and generator. It is totally different that what you are referring to. You have to have a Transfer switch so you done backfeed and try to power to whole neighborhood.

On my RV when on 110v the Convertor powers the 12v side and charges my battery, the Solar also charges the battery at the same time. There is no need for any Transfer switch.

 

[bullfrog]

It gets confusing because you have several options for getting AC power and your RV refrigerator can switch automatically in some cases between AC,DC and propane depending on the refrigerator.
OPTION 1 to get AC power is to plug into grid power.
OPTION 2 to get AC power is to plug into a running generator.
OPTION 3 to get AC power is to turn on an inverter that is powered by a battery bank.

To charge that battery bank you options as well.
OPTION 3A when plugged into grid power the converter converts AC power to DC power and charges the battery bank while AC power is supplied to the trailer outlets.
OPTION 3B when plugged into a running generator the converter converts AC power to DC power and charges the battery bank while AC power is supplied to the trailer outlets. Same as above.
OPTION 3C is charging the battery bank with solar panels via a controller which can be done any time the sun is available whether using either of the options above.
The AC power supplied by options 1,2 and 3 must never use the same circuits at the same time. The fact you have to manually plug in which of the 3 options you wish to use insures this somewhat. When you start hardwiring the systems to make it happen automatically it gets more complicated. Older RVs that had a built in generator hardwired into the trailer circuits had a manual switch 3 position switch that usually had a shore, off and generator position. If you added an inverter you only turned it on when no other AC source was available or you plugged AC accessories directly into the inverter if it was not hardwired. Really a pretty simple fail safe system. When modern RVs started using automatic transfer switches similar to what most RV refrigerators use to control hardwired generators and inverters it was very convenient but hard to understand how it worked. Basically it is hardwired into you trailer circuits and does all the above for you automatically when it works properly. Hope this helps!

 

[Freelander]

Now, this is where I hav questions:

1) I’m going to need a charge controller, so I don’t overcharge the batteries. Correct?
2) I’m going to need some kind of inverter, so I can run appliances off the batteries. Correct?
3) Will I need an automatic transfer switch?
4) Can I charge the batteries off the generator? I’ve read that it can be done, but you need to get the correct hardware/gear.
5) Am I over thinking this? I feel like since I already have $300 generator, I should just install a battery bank, inverter, charge controller sans the solar to save a few bucks.

After rereading the thread, I would recommend a solar kit, it will come with everything you need to hook it up. I have a 400 watt Renogy Kit with a MPPT controller, I added fuses to both the panel wires and charge wire.

You ONLY need an invertor to change 12v to 110v. I use 2 different invertors, a 300 watt unit that is mounted on the wall and is hard wired to my batteries, I use it to run my MacMini Computer and 43" TV, both of these together pull around 60watts. And a 500 watt unit I can plug into a port I added outside, so I can run my Traeger Ranger Grill.

You don't need any Auto Transfer Switch, you have no way to install it, and no way to use. Just use the generator and it will be fine.

Yes the generator will change to batteries without any special hardware. According to the PDF you included about your trailer it has a convertor built in. Also I would get rid of the Big Generator and buy a smaller unit. I have a QG4000 installed in my RV, and I am going to buy a Honda EU2200I just to use to charge batteries. It will also start and run my AC unit after I install an Easy Start unit.

I would add more batteries, and solar to keep everything charged. Also look into 12v appliances. I use a 3 cup Perk Pot for my coffee, I have added a couple of 12v sockets to my RV, I use one to run my CPAP at night, and another one to charge Phone, Tablet and Laptop, just use Car Charges for these and you be fine.

Everything that I buy I try to fine something that is either 12v or can charged from a USB port. I even found a small 4" Waffle Iron that only uses 550 watts.

I have 300 amps of Lithium batteries and 400 watts on the roof, and unless its cloudy or rainy I don't have to run the Generator to charge batteries. And can be back to 100% on the batteries by mid afternoon.

Its all about power management.

 

[bullfrog]

^^^ you have pretty much the ideal system as long as you don’t require air conditioning at night but it has a very expensive price tag to initially purchase and requires space to store and operate. I am able to get by in my 25’ trailer at an elevation of almost 4,000 ft in Arizona with approximately the same power usage as the op described with a 3500 watt generator being run approximately 4 hours a day, 100 watt solar suitcase and two 105 amp hour batteries if I set the thermostat on the heater to 50 degrees at 9 PM (the latest permitted time to run a generator). I do not use an inverter and do not use AC accessories when the generator is not running. In the morning on cold nights the batteries will be close to 50% discharged. I plan to double the battery bank and use 305 watts of solar and MPPT controller this next year to increase battery life although these batteries are already several years old. Having a 3500 watt generator ($300) and buying four $99 batteries ($396) and a solar panel and 30 amp MPPT controller and wiring for less than approximately $400 means the op would have a total of $1096 for a comparable or better system than I have now. I believe that would be less that the cost of you generator alone. He will probably want a system that is quieter and has a longer life but if he is only occasionally using the trailer this system may do. He will have to learn to do without AC power late at night. I would highly recommend running the generator first thing in the morning to get bulk charging done and in the evening to insure batteries are fully charged each day.

 

[ExploringOne]

So I think I figured it out.

What I learned, if everyone else has read this far.

INVERTER/CONVERTER = The magic bullet, a few that I've looked at include an automatic transfer switch. It's an all in one.

So my steps would be

Replace the Converter (battery charger) in my panel with an Inverter/Converter combo. This will allow me to pull battery from my 12v/24v battery system and power the inside circuitry and electronics. If it has a built in transfer switch (I don't know that they all do, so do your research), then I don't have to really worry about charging/draw from the battery bank.

Now, it's time to figure out battery storage... which is going to probably be my most expensive part.

 

[Freelander]

What 'circuitry and electronics' are you trying to power?

You don't need to change the convertor, it will charge your batteries just fine.

You don't need a transfer switch, you have NO WAY to hook it up.

If you want to convert 12v to 120v all you need is an invertor.

 

[Freelander]

A Transfer Switch is used to transfer power between a BUILT GENERATOR AND SHORE POWER, not between 12v and 120v.

Look at the pictures I uploaded my 3- amp cable is plugged into Generator output receptacle, if I what to to use Shore power I pull the plug and plug ii into the pedestal for power, if I want to use the generator, I plug it in here. I don't have an Transfer Switch.

If I want to use 12v to power any 110v item I use am inverter to do that. This is a 500 watt plugged into a 12v DC plug that I added.

You have NO WAY to install a Transfer Switch.

 

[ExploringOne]

.

 

[ExploringOne]

[font=Tahoma, Verdana, Arial, sans-serif]So, I’ve been trying to respond and edit my post, I keep getting 404 errors from the website. I’m going to try and answer your questions from memory.[/font]

[font=Tahoma, Verdana, Arial, sans-serif]What kind of electronics?[/font]

[font=Tahoma, Verdana, Arial, sans-serif]The main thing would be my work laptop that requires A/C.[/font]
[font=Tahoma, Verdana, Arial, sans-serif]The remaining things I could charge off 12v D/C load. Propane heater/fan, charging of my phone, my cell hotspot, my macbook, and my tablet. The water pump would also be able to run occasionally as I use the water tank.[/font]

[font=Tahoma, Verdana, Arial, sans-serif]About not needing to change out my converter.[/font]

[font=Tahoma, Verdana, Arial, sans-serif]I suppose I don’t need to, as it runs at 55 amps/hour and that’s a fairly fast battery charger.[/font]

 

[ExploringOne]

About not needing a transfer switch.

Yes, yes I would need one. If I’m going to possibly plug into the shore/generator while my battery bank is on, I would need it so I don’t back feed and or blow things up.

About needing only a 12v inverter.

I see how your setup is, and it looks like you’re plugging your inverter into the 30 amp connection on the outside of your camper, that is one way to do things I suppose. Also, when using it in this fashion, you’re correct, you would not need an automatic transfer switch.

 

[Freelander]

NO, NO, NO, you absolutely do not need a transfer switch, how many times do I have to tell you this???? You need to forget about the transfer switch!!!

The transfer switch is used to switch from the ON BOARD GENERATOR to SHORE POWER, it has absolutely NOTHING to do with your battery bank.

There is NO backfeed!!!!

The convertor supplies power to the 12v side and charges the battery bank.

My inverter is wired directly to my battery bank. 

No when I plug into Shore Power I unplug from the Generator and plugin Shore Power, when I am on Generator I plug into the 30 amp receptable.

I use can use my Generator at the same time as my battery bank. There is NO BACKFEED!!!

 

[ExploringOne]

So, let me get this straight, from looking at your pictures.

- Battery Bank -> - RV <- Generator _OR_ Shore

Your battery bank is on your RV and you have an inverter connected to it.

When you wish to use your inverter, you have a 30/50 amp plug on it? You walk outside, unplug shore/generator from your "POWER IN" jack, and you plug your male end from your inverter into the "POWER IN" on the RV?

 

[Freelander]

[font=Tahoma, Verdana, Arial, sans-serif]So, I’ve been trying to respond and edit my post, I keep getting 404 errors from the website. I’m going to try and answer your questions from memory.[/font]

[font=Tahoma, Verdana, Arial, sans-serif]What kind of electronics?[/font]

[font=Tahoma, Verdana, Arial, sans-serif]The main thing would be my work laptop that requires A/C.[/font]
[font=Tahoma, Verdana, Arial, sans-serif]The remaining things I could charge off 12v D/C load. Propane heater/fan, charging of my phone, my cell hotspot, my macbook, and my tablet. The water pump would also be able to run occasionally as I use the water tank.[/font]

[font=Tahoma, Verdana, Arial, sans-serif]About not needing to change out my converter.[/font]

[font=Tahoma, Verdana, Arial, sans-serif]I suppose I don’t need to, as it runs at 55 amps/hour and that’s a fairly fast battery charger.[/font]

This is what I use to charge my MacBook Pro, its an older model 2012, they do make chargers for there newer models. I installed a 12v socket to charge my MacBook Pro, my iPhone, my iPad, and my hotspot. I have installed 5 12v sockets in the RV, and I have numerous USB ports as well, and my MBP charger has USB ports as well.

I use a Mr Heater for heat, its not ideal, but it works requires no electricity to run. I plan to switch it out for a better model.

Your water pump won't use enough electric to notice.

Just add more batteries and some solar. 

Like I stated I have 3 Battleborns, but a good set of 6v, 12v Deep Cycles will work. And I have 400 watts on the roof, but 200 watts may be enough.

 

[Freelander]

So, let me get this straight, from looking at your pictures.

- Battery Bank -> - RV <- Generator _OR_ Shore

Your battery bank is on your RV and you have an inverter connected to it.

When you wish to use your inverter, you have a 30/50 amp plug on it? You walk outside, unplug shore/generator from your "POWER IN" jack, and you plug your male end from your inverter into the "POWER IN" on the RV?

I never unplug the Shore power cable, there is no reason to, it stays plugin all the time. There is NO backfeed.
No the invertor is wired with 10AWG wire straight from the battery bank, I have an inline 30amp DC breaker in the line as well.

 

[Freelander]

The 12v side and the 110v are completely separate systems. The convertor is there to charge the battery and provide 12v power when the on Shore/Generator.

All the lights, Fridge, water pump, and furnace, are all 12v. The only thing that require 110v are the Microwave and the AC.

 

[bullfrog]

If the only thing you are going to need 120 volt AC power is to maintain the charger for your computer then a small inverter with a 120 volt plug in made into it from the manufacturer is all you need. The inverter can be turned on when you need 120 volts and your computer can be plugged in to an extension cord if need be. When you are not charging the computer simply turn off the inverter. These inverters depending on how many watts of power you need can simply plug into a 12 volt DC circuit or attach by alligator clips or the best way with ring terminals to any 12 volt DC source, even your car or truck but in this case your trailer’s battery bank just make sure the 12 volt DC circuit wiring is heavy enough to meet the inverter’s power needs. DC current works best over short distances so you want the inverter to be close to your battery bank if possible. AC current works better over longer distances hence the extension cord may be necessary. Most inverters use battery power when turned on whether or not you have anything plugged into them so be sure to turn off the inverter when you are not using it.