Newbie wants Direction!

[Mark44]

OK so newb here, with aspirations of....

Anyway, I have a fifth wheel trailer. It uses a 50 amp converter.
I have a Champion Generator to use when off grid. (30 amp but capable of paralleling for 50)
I want to add Solar, but maybe not until spring or summer of '21.
I want to add a LIFEPO4 battery bank now to replace LA (original house batt)
I also want to be sure that once I do, I can use an inverter to power the coach.

So what I am trying for is this:
Solar ready
280 AH battery (rising to 840 AH as time and $ permit)
Switching mechanism or manual method for ensuring:
1) generator can charge the battery(s)
2) can switch from shore power to generator (manual start)
3) can feed back battery bank through an inverter to power the coach

With all that said I obviously need help!
I have electronic experience, and have ordered a set of cells from China already. But I have never tried something this complicated.

I look to the intelligencia here for guidance please.

 

[snoobler]

Welcome to the forum.

Immediate steps needed:

1. Confirm that your converter is compatible with LFP
2. Order a BMS so that it's here before your cells, make sure the BMS current supports your needs. Ensure it also has low temperature charging protection if there's any chance it will be subjected to freezing temperatures.
3. Order a 30V/10A power supply
4. Determine viability of any existing alternator charging from the tow vehicle.

Concerning your items, 1), 2) and 3), those are all possible and relatively simple.

Is your coach umbilical 50A or 30A?

Have you conducted an energy audit to assess your actual power needs? (link #1 in my signature if you need one).

I recommend you click "DIY SOlar Blueprints" above and check out the various system blueprints for ideas and "Solar Components" for hardware, tools and testing products.

 

[Hedges]

Consider an inverter/charger or hybrid (with PV input as well)
That would take care of feeding your trailer from either inverter or external AC source (shore power or generator), but limited to it's pass-through current.

The ideal one would use all available PV, only draw as much power from generator as was needed in excess of PV. Many won't do that because it requires synchronizing inverter to AC input. Simpler and compatible with most (maybe all) would be generator just charges batteries (maybe runs a heavy load like A/C), and inverter feeds everything else - in this case you want a switch between inverter/shore power.

Is generator part of trailer already? Since you say capable of paralleling I'm guessing not.

Some inverters already have separate grid and generator inputs. Otherwise, you can put in an automatic or manual transfer switch. Or, plug shore power plug into the generators.

 

[Mark44]

Thanks for the quick responses. I will review these today and add further questions (I know, what a PITA right?)!

 

[Byrogie]

I have this in my 50amp RV:

IC Series 2000-watt Inverter Charger

Go Power!'s IC Series 2000-watt Inverter Charger is an inverter, battery charger and transfer switch in one compact unit.

gpelectric.com

A/C passthrough, hardwired 2 legs to RV panel. Charger is programmable via remote.
Solar, Portable generator for air conditioner and supplemental charging when needed.
Removed the converter.

 

[snoobler]

I have this in my 50amp RV:

IC Series 2000-watt Inverter Charger

Go Power!'s IC Series 2000-watt Inverter Charger is an inverter, battery charger and transfer switch in one compact unit.

gpelectric.com

A/C passthrough, hardwired 2 legs to RV panel. Charger is programmable via remote.
Solar, Portable generator for air conditioner and supplemental charging when needed.
Removed the converter.

A/C usually means Air Conditioning...

There are pretty inexpensive 3kW versions too. The kicker is the split phase. If one has 50A input to their 5th wheel, 240VAC split phase make it a little easier to manage when integrating with 240VAC generators and 50A shore power. If one has 30A service, there is no value in having a 240VAC split phase inverter. A 120VAC inverter creates challenges integrating with 240VAC input.

Once an inverter/charger is in place, it's completely appropriate to remove/un-plug the converter.

 

[Mark44]

Awesome, I am soaking all this up. My head is swelling with Knowledge!

Going to have to do sum figurin as they say here in East TN.

Keep the thoughts and suggestions coming, PLEASE!

 

[Hedges]

"

Transfer Relay Rating

2 legs at 50A each (120V each leg)

"

Appears to be a 120V inverter, but passes through 120/240V split phase if connected to 50A 120/240V shore power. Also works with 30A 120V shore power.

The one thing this probably doesn't do is deliver inverter power from the battery (given PV coming in through a separate charge controller) while loading generator only for what PV can't produce.

If you have a generator, you could either run in through this inverter/charger to power loads while charging battery,
Or you could use it to power a separate battery charger set for a lower voltage than the PV charger. Then its current should taper off to nothing allowing all PV power to be used, or help out when battery voltage droops. Not perfect, but reduces fuel consumption.

If battery can accept full current from inverter charger in addition to PV, in case of low battery you start generator and let both sources charge the battery, and AC loads will be from generator (pass-through relay) not inverter off battery.

 

[Byrogie]

A/C usually means Air Conditioning...

There are pretty inexpensive 3kW versions too. The kicker is the split phase. If one has 50A input to their 5th wheel, 240VAC split phase make it a little easier to manage when integrating with 240VAC generators and 50A shore power. If one has 30A service, there is no value in having a 240VAC split phase inverter. A 120VAC inverter creates challenges integrating with 240VAC input.

Once an inverter/charger is in place, it's completely appropriate to remove/un-plug the converter.

Yes I always get confused with A/C and AC, my bad.

 

[Byrogie]

"

Transfer Relay Rating

2 legs at 50A each (120V each leg)

"

Appears to be a 120V inverter, but passes through 120/240V split phase if connected to 50A 120/240V shore power. Also works with 30A 120V shore power.

The one thing this probably doesn't do is deliver inverter power from the battery (given PV coming in through a separate charge controller) while loading generator only for what PV can't produce.

If you have a generator, you could either run in through this inverter/charger to power loads while charging battery,
Or you could use it to power a separate battery charger set for a lower voltage than the PV charger. Then its current should taper off to nothing allowing all PV power to be used, or help out when battery voltage droops. Not perfect, but reduces fuel consumption.

If battery can accept full current from inverter charger in addition to PV, in case of low battery you start generator and let both sources charge the battery, and AC loads will be from generator (pass-through relay) not inverter off battery.

Yes, can plug in 50 amp cord to shore power, or with 50/30 adapter to generator. It does invert power from batteries when not plugged to AC input. Solar goes direct to batteries. Inverter Charger used to supplement when needed. Adjustable charging profile, inverter and solar controller. Use either or both depending on circumstances.

 

[snoobler]

"

Transfer Relay Rating

2 legs at 50A each (120V each leg)

"

Appears to be a 120V inverter, but passes through 120/240V split phase if connected to 50A 120/240V shore power. Also works with 30A 120V shore power.

The one thing this probably doesn't do is deliver inverter power from the battery (given PV coming in through a separate charge controller) while loading generator only for what PV can't produce.

If you have a generator, you could either run in through this inverter/charger to power loads while charging battery,
Or you could use it to power a separate battery charger set for a lower voltage than the PV charger. Then its current should taper off to nothing allowing all PV power to be used, or help out when battery voltage droops. Not perfect, but reduces fuel consumption.

If battery can accept full current from inverter charger in addition to PV, in case of low battery you start generator and let both sources charge the battery, and AC loads will be from generator (pass-through relay) not inverter off battery.

Agreed. Specs are misleading, but the manual clearly indicates split phase capable:

3.6.8:

https://s3-us-west-2.amazonaws.com/catsy.549/79497_MANUAL_GP-IC-Series_RevH-min.pdf

 

[Mark44]

A/C usually means Air Conditioning...

There are pretty inexpensive 3kW versions too. The kicker is the split phase. If one has 50A input to their 5th wheel, 240VAC split phase make it a little easier to manage when integrating with 240VAC generators and 50A shore power. If one has 30A service, there is no value in having a 240VAC split phase inverter. A 120VAC inverter creates challenges integrating with 240VAC input.

Once an inverter/charger is in place, it's completely appropriate to remove/un-plug the converter.

So,

I have several questions based on some of the comments that were provided.

It appears that a combination inverter/charger is much more expensive than doing the two items separately. Is that true? If so, why would you bother with this combination unit?

I get removing the Converter once an inverter is in place. However, not sure how the charger would feed the 12 volt side of the coach needs? Does it act as a converter for the 12 volt systems?

I get it that once I have a solar panel or six in place, that maybe a moot point, but I am trying to put my game plan together, so all responses gratefully accepted.

Mark44

 

[Hedges]

I'd say prices are all over the map, from $300 to $5000.
You pick the features and capabilities you want and the quality/reputation you want, within budget.
Of course, size is a benefit, combined means less battery cable wiring, can be simpler to use.

I see people here considering all-in-one inverter/charger/PV units that are 1/10th the MSRP of of the equipment I'm using.

 

[Byrogie]

So,

I have several questions based on some of the comments that were provided.

It appears that a combination inverter/charger is much more expensive than doing the two items separately. Is that true? If so, why would you bother with this combination unit?

I get removing the Converter once an inverter is in place. However, not sure how the charger would feed the 12 volt side of the coach needs? Does it act as a converter for the 12 volt systems?

I get it that once I have a solar panel or six in place, that maybe a moot point, but I am trying to put my game plan together, so all responses gratefully accepted.

Mark44

The 12 volt comes straight from the battery to the trailer. Same as now if you are not plugged into shore power.

So,

I have several questions based on some of the comments that were provided.

It appears that a combination inverter/charger is much more expensive than doing the two items separately. Is that true? If so, why would you bother with this combination unit?

I get removing the Converter once an inverter is in place. However, not sure how the charger would feed the 12 volt side of the coach needs? Does it act as a converter for the 12 volt systems?

I get it that once I have a solar panel or six in place, that maybe a moot point, but I am trying to put my game plan together, so all responses gratefully accepted.

Mark44

 

[Byrogie]

Well that was fun, posted from my phone, it got confused.
Anyway, when unplugged, 12 volt comes from the batteries to the trailer. When plugged in it comes from the converter, which also charges the batteries while in use.
From there you can add solar to charge batteries and inverter to invert 12 volt to 120AC while unplugged/boondocking. The advantage of inverter/charger is convenience, not having to pull out portable charger. Your solar charge controller and inverter/charger must be programmable as you need different parameters for LIFEPO4 batteries.
So, you need to envision what you need and size accordingly. How much boondocking? What will your power usage be? What is your trailer power now, 30 amp or 50 amp? What do you want to power when boondocking? Energy audit needed first.
Size batteries, solar, inverter/charger accordingly. Lots of options out there.....
My situation:
Trailer is 50 amp parked in a park year round, no power. I have 675 amp/hr of FLA batteries, 560 watts of solar, 2000 watt inverter/charger (programmable charge profiles and up to 100 amps charging) hardwired to trailer main panel, and 3000 watt generator. I use propane for fridge and furnace, 120 volt for TV, cell booster, hair dryer (wife, not me), coffee pot, ceiling fan, device and power tool charging, and a bar fridge in the bay for cold beverages.
Summer plenty of sun to cover usage through solar. run the generator the odd time for A/C when it gets really hot, which is not often. Supplement charging with generator through inverter/charger mostly in spring and fall when sun is limited.

Cheers