Upgrade to Lithium

[JEH-THOR]

I have,
2020 Axis 27.7 (30A) with
4 AGM 100 Ah batteries
Onan QG 4000 Generator (33.3A)
WF 8955 Converter (13.6Vdc lead acid only)
ProWatt SW 2000 Inverter (Xantrex)
GoPower battery monitor (negative side of battery)
PMON-5S battery monitor (positive side of battery)
2 190W solar panels (looks like about 5A at high noon)

Problem:

I use about 120 Ah to 150 Ah (no: microwave; coffee maker; space heater; etc. Use: 2 TVs, 2 dish wallys; starlink; minimual lights +??? leakage) at night boondocking in a California state park starting with about an 85% State of charge (SoC) and ending with about 62% SoC. After running the generator for about 10 hours, the batteries don't come back up to 85%. In other words, 10 hours on the generator doesn't replace the current lost during the night. By the 3rd night, I can't get through the night without shutting the batteries down.

Objective:

1. Reduce the generator time and still increase the SoC. It would be nice to run the generator only maybe three hours.
2. Reduce the noise of the generator (neighbor complaints).

It occurs to me to replace the AGM batteries with 1 LiTime 400 Ah LiFePO4 battery may be a good idea. I am electric illiterate and when calling some battery vendors, they don't seem to understand or be able to design an entire system.

So, what do you folks recommend? i.e. converter and configuration; wire size for the 6' from converter to battery; and any other ideas to solve my SoC problem. I would rather solve the problem rather than cut costs.

As for noise, I have no idea whether a muffler would work but suspect changing the exhaust back pressure may be a problem.

Thanks.

 

[Chateau_Nomad]

So you're consuming around 80 - 90 amps. Seat of pants says you should be able to recover that in maybe four hours.

I suspect you have a converter issue... AND you should be getting twice the solar amps in full sun.

Before jumping in on a lithium upgrade, I'd check the functionality of your existing system. Battery health, generator output, solar charge controller settings, loose/corroded cable connections etc. etc. Because if your DC charging is not optimal, you'll have the same issue with LiFePO4 batteries.

 

[JEH-THOR]

Chateau_Nomad- Thanks. The converter is brand new. I replaced the original stock converter because the old one was putting out 30Vdc. New one is at 36 Vdc which meets specs. Didn't seem to change charging time.

Just yesterday after I left boondock campground, I noticed while driving that the power monitor showed +50 A recharging from the chassis engine. After an hour of driving, it showed about +44 A. On generator startup the prior day, power monitor showed +20A on generator startup. By the end of the day, it read about +5A. I don't know enough to know what all that means or why the difference. Although, I read that an engine alternator puts out about +100 A.

 

[JEH-THOR]

Upgrade to lithium

And how do I check "Battery health, generator output, solar charge controller settings,"

 

[Bob Nodine]

I have,
2020 Axis 27.7 (30A) with
4 AGM 100 Ah batteries
Onan QG 4000 Generator (33.3A)
WF 8955 Converter (13.6Vdc lead acid only)
ProWatt SW 2000 Inverter (Xantrex)
GoPower battery monitor (negative side of battery)
PMON-5S battery monitor (positive side of battery)
2 190W solar panels (looks like about 5A at high noon)

Problem:

I use about 120 Ah to 150 Ah (no: microwave; coffee maker; space heater; etc. Use: 2 TVs, 2 dish wallys; starlink; minimual lights +??? leakage) at night boondocking in a California state park starting with about an 85% State of charge (SoC) and ending with about 62% SoC. After running the generator for about 10 hours, the batteries don't come back up to 85%. In other words, 10 hours on the generator doesn't replace the current lost during the night. By the 3rd night, I can't get through the night without shutting the batteries down.

Objective:

1. Reduce the generator time and still increase the SoC. It would be nice to run the generator only maybe three hours.
2. Reduce the noise of the generator (neighbor complaints).

It occurs to me to replace the AGM batteries with 1 LiTime 400 Ah LiFePO4 battery may be a good idea. I am electric illiterate and when calling some battery vendors, they don't seem to understand or be able to design an entire system.

So, what do you folks recommend? i.e. converter and configuration; wire size for the 6' from converter to battery; and any other ideas to solve my SoC problem. I would rather solve the problem rather than cut costs.

As for noise, I have no idea whether a muffler would work but suspect changing the exhaust back pressure may be a problem.

Thanks.

You need to add a high current charger from the generator. The converter is just not putting out enough current to fast charge the battery bank.

Something like this should do the job. You could install it permanently to run off either the generator or shore power.

https://www.amazon.com/STANLEY-BC25...35011&s=automotive&sr=1-6&ts_id=15707061&th=1

 

[16ACE27]

Chateau_Nomad- Thanks. The converter is brand new. I replaced the original stock converter because the old one was putting out 30Vdc. New one is at 36 Vdc which meets specs. Didn't seem to change charging time.

Just yesterday after I left boondock campground, I noticed while driving that the power monitor showed +50 A recharging from the chassis engine. After an hour of driving, it showed about +44 A. On generator startup the prior day, power monitor showed +20A on generator startup. By the end of the day, it read about +5A. I don't know enough to know what all that means or why the difference. Although, I read that an engine alternator puts out about +100 A.

You need to add a high current charger from the generator. The converter is just not putting out enough current to fast charge the battery bank.

Something like this should do the job. You could install it permanently to run off either the generator or shore power.

https://www.amazon.com/STANLEY-BC25...35011&s=automotive&sr=1-6&ts_id=15707061&th=1

I agree with Bob as far as the path of least resistance - smart converter/chargers aren't always that smart, especially in parallel with solar chargers, and they kick into float mode way too early.

But I gotta question this statement of yours:

"the old one was putting out 30Vdc. New one is at 36 Vdc which meets specs."

Did you mean 13.0 and 13.6 VDC?

 

[Mark54]

I have,
2020 Axis 27.7 (30A) with
4 AGM 100 Ah batteries
Onan QG 4000 Generator (33.3A)
WF 8955 Converter (13.6Vdc lead acid only)
ProWatt SW 2000 Inverter (Xantrex)
GoPower battery monitor (negative side of battery)
PMON-5S battery monitor (positive side of battery)
2 190W solar panels (looks like about 5A at high noon)

Problem:

I use about 120 Ah to 150 Ah (no: microwave; coffee maker; space heater; etc. Use: 2 TVs, 2 dish wallys; starlink; minimual lights +??? leakage) at night boondocking in a California state park starting with about an 85% State of charge (SoC) and ending with about 62% SoC. After running the generator for about 10 hours, the batteries don't come back up to 85%. In other words, 10 hours on the generator doesn't replace the current lost during the night. By the 3rd night, I can't get through the night without shutting the batteries down.

Objective:

1. Reduce the generator time and still increase the SoC. It would be nice to run the generator only maybe three hours.
2. Reduce the noise of the generator (neighbor complaints).

It occurs to me to replace the AGM batteries with 1 LiTime 400 Ah LiFePO4 battery may be a good idea. I am electric illiterate and when calling some battery vendors, they don't seem to understand or be able to design an entire system.

So, what do you folks recommend? i.e. converter and configuration; wire size for the 6' from converter to battery; and any other ideas to solve my SoC problem. I would rather solve the problem rather than cut costs.

As for noise, I have no idea whether a muffler would work but suspect changing the exhaust back pressure may be a problem.

Thanks.

I'd start from scratch in your case- add a Balmar Under hood generator, which is much quieter, and uses the chassis engine's emission controls, add as many PV panels as possible, change charging system and monitoring using all Victron components, and try to get as mnay Watt-hours as possible-

I moved my LFP batteries from the bottom, and went from 200Ah to 600Ah, changed PV controller from PWM to MPPT, already had the UHG, added smartlink to the UHG regulator, and more. My rig is 30A as well.

This post by another, "TheRealMcCoy" shows a great schematic for a basic system- pdf at the bot. of his post:
https://www.thorforums.com/forums/f27/electric-upgrade-36195.html
Can be a daunting task if you are not versed in DC electrics, but study the pdf, and follow the pathways. Wire size and fusing are very important. Also keep wire lengths as short as possible. You can modify to adopt to 30A.

My final move will be changing the roof AC to a 12V unit, which is lower amp draw and much quieter inside as well. I'm using the Mabru 12V one:
https://www.vanlifeoutfitters.com/store/mabru-rv-12000-12-volt-dc-air-conditioner/

Renogy and others have online calculators for learning what you need. Dealers will generally not have any idea, so you are on your own, like the rest of us.
DavidEM suggests an RV Tech, which is a great idea as well.

 

[DavidEM]

Your problem, perhaps among others, is the converter. The WFCO 8955 is a POS IMO. I replaced mine with a Progressive Dynamics 60 A converter and my charging current trippled. That was with 200 Ahs of AGMs.

With your 400 Ah AGM battery bank you could go as high as 100 amps and be safe. That would cut your generator running time to a few hours as well as load the generator better.

Not sure what is going on with your solar panels. How are they wired, series or parallel. What type of solar controller are you using, PWM or MPPT? If you have them wired in series to PWM controller then you are losing half your potential solar power as PWM controllers simply “pulse out” any input voltage above approximately 12 V.

If you have them wired in parallel and are using the OEM 10 gauge wire from the roof to the controller, then the resulting voltage drop is destroying their output.

You need to find an electrically savvy RV tech to help you sort through this.

David

 

[macdaddy1111]

Should be getting around 20 amps of solar on 380 watts at full sun

U really only have 200ah of juice

Best thing I ever did was dump the boat anchors and install lithium

If u a boondoggle, will surely improve your experience!

Also sounds like you have some ghost power to hunt down. I installed 1/2 dozen wifi power bars that i can turn off or on via phone!

 

[Mark54]

I have,
2020 Axis 27.7 (30A) with
4 AGM 100 Ah batteries
Onan QG 4000 Generator (33.3A)
WF 8955 Converter (13.6Vdc lead acid only)
ProWatt SW 2000 Inverter (Xantrex)
GoPower battery monitor (negative side of battery)
PMON-5S battery monitor (positive side of battery)
2 190W solar panels (looks like about 5A at high noon)

Problem:

I use about 120 Ah to 150 Ah (no: microwave; coffee maker; space heater; etc. Use: 2 TVs, 2 dish wallys; starlink; minimual lights +??? leakage) at night boondocking in a California state park starting with about an 85% State of charge (SoC) and ending with about 62% SoC. After running the generator for about 10 hours, the batteries don't come back up to 85%. In other words, 10 hours on the generator doesn't replace the current lost during the night. By the 3rd night, I can't get through the night without shutting the batteries down.

Objective:

1. Reduce the generator time and still increase the SoC. It would be nice to run the generator only maybe three hours.
2. Reduce the noise of the generator (neighbor complaints).

It occurs to me to replace the AGM batteries with 1 LiTime 400 Ah LiFePO4 battery may be a good idea. I am electric illiterate and when calling some battery vendors, they don't seem to understand or be able to design an entire system.

So, what do you folks recommend? i.e. converter and configuration; wire size for the 6' from converter to battery; and any other ideas to solve my SoC problem. I would rather solve the problem rather than cut costs.

As for noise, I have no idea whether a muffler would work but suspect changing the exhaust back pressure may be a problem.

Thanks.

The other thing I suggest is convert everything to watts- AC or DC doesn't matter- watts are universal. So if you have 20Ah batteries, then you have 12x200= 2400Wh of power- so just add up all your devices in watts (VxA=W) and see what you need, and go from there. If all you see is amps and volts on the label, easy to convert to watts.

I now have 600Ah x 12= 7200Wh of power, and 380W solar on MPPT at 97% efficiency now- so when I get my new 12V AC, I can run for days instead of hours, w/o solar.

 

[JEH-THOR]

Move to Lithium

Yes, I meant 13.0 and 13.6 Vdc.,

Mark54 - Am I correct that you meant 200 Ah battery instead of 20Ah battery? I ask so i can understand the watt calc.

Let me catch up on the other posts. Thanks.

 

[JEH-THOR]

David -
"You need to find an electrically savvy RV tech to help you sort through this."

Any idea how to find such a person?

 

[JEH-THOR]

Mark-
"I moved my LFP batteries from the bottom, and went from 200Ah to 600Ah, changed PV controller from PWM to MPPT, already had the UHG, added smartlink to the UHG regulator, and more. My rig is 30A as well."

Please take me to school. What is PWN, MPPT and UGH and smartlink?

Also, I see the outstanding diagram diagram and don't understand it. It is way over my head.

 

[DavidEM]

David -
"You need to find an electrically savvy RV tech to help you sort through this."

Any idea how to find such a person?

It will be difficult, but boats have similar electrical systems, so ask around at local marinas, particularly dockmasters.

Let me tackle a few of the acronyms mentioned:

PWM is pulse width modulation controller and should only be used with 12V nominal panels stand alone or wired in parallel. If 24V panels or two 12V panels are used with a PWM controller it will simply cut the pulse width (or maybe burn up) to keep the voltage within what the battery needs, a nominal 12V.

MPPT is maximum power point controller which converts 12-xx V input to the voltage that the battery needs on the output while keeping the input voltage at its optimum, usually 15 V for nominal 12V panels.

UHG- under hood generator. Usually a separate generator from the normal chassis generator that is driven by the chassis engine. It takes the place of an Onan built into the RV.

David

 

[JEH-THOR]

David - Thanks a bunch. I think I'm learning.
"
Your problem, perhaps among others, is the converter. The WFCO 8955 is a POS IMO. I replaced mine with a Progressive Dynamics 60 A converter and my charging current trippled. That was with 200 Ahs of AGMs.

With your 400 Ah AGM battery bank you could go as high as 100 amps and be safe. That would cut your generator running time to a few hours as well as load the generator better.

Not sure what is going on with your solar panels. How are they wired, series or parallel. What type of solar controller are you using, PWM or MPPT? If you have them wired in series to PWM controller then you are losing half your potential solar power as PWM controllers simply “pulse out” any input voltage above approximately 12 V.

If you have them wired in parallel and are using the OEM 10 gauge wire from the roof to the controller, then the resulting voltage drop is destroying their output."

1. Isn't the converter amp output limited by the output of the generator? The Onan 4000k generator has a max of 33.3 amps. Would any converter amp capacity in excess of the generator output be wasted?

2. No clue on the solar panels. I bought the RV used from a dealer and added a 190 Watt solar panel to one that already existed and an inverter both of which the dealer installed. The dealer may have installed the inverter switches wrong because when I am connected to shore power and turn the inverter on and unplug the shore power, the microwave clock and the television go off but the dish wally controller stays on. I'm guessing the issue may be a transfer switch that doesn't but the inverter fast enough perhaps because a delay setting isn't turned off.

3. What did your charging time go from and to?

4. What size is your generator?

 

[Mark54]

Mark-
"I moved my LFP batteries from the bottom, and went from 200Ah to 600Ah, changed PV controller from PWM to MPPT, already had the UHG, added smartlink to the UHG regulator, and more. My rig is 30A as well."

Please take me to school. What is PWN, MPPT and UGH and smartlink?

Also, I see the outstanding diagram diagram and don't understand it. It is way over my head.

What DavidEM said- plus the PWM controller can be 50-60% efficient, vs. MPPT at 90-97% efficient. Also PWM is cheap, and MPPT is more expensive.

Also many come with two, 100A coach batteries. Ah= Amp hour, or how many amps you can have in one hour.

So, with 2 x 100A batteries, you have 200A, or 200Ah. Then x 12V= 2400Wh, or how many watts are available for 1 hour. But you have more than an hour to use all 2400W if you don't try to run too much at once.

So when I say I have 600Ah, I have two 300A batteries, so 2 x 300= 600Ah, x 12V = 7200Wh. I can do a lot more now with that much power.

The smartlink is an bluetooth module that allows me to adjust settings on my UHG regulator. Otherwise it can overheat. To adjust w/o that, I would have to go inside direct to the regulator and do it with a magnetic screwdriver! No way.
Without ease of changing settings, the UHG can overheat- as said, it is a 2nd alternator and can get pretty hpt, so being able to change temp limits by phone is handy.


Hope that helps!!

Mark

 

[16ACE27]

1. Isn't the converter amp output limited by the output of the generator? The Onan 4000k generator has a max of 33.3 amps. Would any converter amp capacity in excess of the generator output be wasted?

No, the converter output is limited by the converter itself - in your case 55 amps at 14 VDC so basically 800 watts maximum. The converter runs off the 120 VAC either from SP or the generator, so you can see the load from the converter doesn't even reach 1/4 of the generator's 4000 watt capacity.

 

[DavidEM]

JEH:

Read the last sentence of my post #8 again, and again, and again…….

We aren’t even on the same page.

David

 

[JEH-THOR]

Lithium upgrade

David-
Do you mean about finding a knowledgeable tech?
Jim

 

[Mark54]

David-
Do you mean about finding a knowledgeable tech?
Jim

Assignment: Read this article, and then google some more about RV electrical systems.
https://www.rvingbeginner.com/rv-electrical-systems
Some things to keep in mind- Power refers to electrons flowing thru wires to the device that is 'demanding' the power. Power is not under pressure, nor is it 'pushed' thru the wires- rather it is latent and waiting to be 'called' for duty.
So when you turn on a toaster, a switch is turned on and allows the electricity to be pulled in by the device. A typical toaster can be 1000-1500 watts,which is pretty high as devices go. The 'garden hose' theory of electricity is not a valid one!

DC and AC are the two types of power used in an RV. DC is Direct Current, and AC is Alternating current.

DC electrons flow in a constant manner thru the wires, and generally require a larger conductor because of that. We have DC power for the lower voltage devices in our RV. A 12V motor is much smaller than a 120V AC motor for example. It also uses fewer watts than an AC motor, and hence can have a small wire to it.

AC is Alternating Current, and 'vibrates' or 'alternates' electrons back and forth, is more efficient (hence why it is used in homes) and does not need huge wires to carry it. If you look at the label on a toaster, you may see "60 cps", or 60 cycles, which is a standard for AC power- means that the alternating of electrons between the hot (black wire) and neutral (white wire) are occurring 60 times in a second (cps= cycles per second)

I've been 'zapped' by 120V a few times (DONT DO THIS) just working on my home systems- touching the neutral wire, and could fell the 'buzz' of the current, or alternating of the electrons- most unpleasant feeling. It can kill you if you are in the wrong place. It may only take a few amps to kill someone. Electricity is to be respected- it is an invisible force!!

The circuit breakers in your home are there in case you 'pull' too much power thru a wire- like having too many heaters on a single wire, like a power strip with 6 outlets- If you plug six 1500W heaters into all those and it will pop it's own fuse, or burst into flames, because too many electrons are being 'called to duty' and pile up inside the copper wire and power strip, and cause it to overheat.
If that doesn't happen first, then the breaker in your home panel will overheat, and 'trip' to open position to stop the flow of electrons. If the breaker is faulty, the house can burn down!!!

If your home was DC powered, the wires out on the poles would be so large, the poles would not be able to carry it.

Read this article to better understand (there are better articles- google: AC vs DC electricity)
https://learn.sparkfun.com/tutorials/alternating-current-ac-vs-direct-current-dc/all
Beyond that- google to find "Mobile RV tech" and have them help you understand the RV- it is important that you have a basic knowledge to keep you and family safe!!

If after reading all that, you don't understand, find a place to take a course, like a community college. I don't understand why this is not taught in high school. Maybe the electrical union has something to do with that...?
In 4 years, we'll build a radio together....