If you have done this, I'd like to hear just what & how you proceeded to switch out.

Here's what I think so far:

* The charge portion of the 'converter' has to be shut-off (dis-connected).

Here I wonder if that line could be used to run into a LiPo controller? Sounds way too easy..

* A 12v source of power to the LiPo charger. Solar while off-grid and though the converter (shore or TV sourced). 

* Dedicated LiPo charger

Questions are a few, yet the big one right now is the TV power coming back into the trailer. I assume it's run through the converter's battery controller and sent forward to the battery. Not any sort of direct connection, TV to TT battery.

1) You need a charger set up for Li batteries. The  ac circuit for the WFCO charger can be used to feed that charger.

I have my LiPo battery, covered.

I have a solar charge controller, covered.

I'd like to use the solar controller to to charge from the Pod's 12v system. I figure I should be able to do that..

Is it feasible to use the existing battery cables?  Converter out (battery cables) > LiPo controller > LiPo battery? I would believe the LiPo controller now takes control and power is sent back as normal when dry-camping. By doing this, the TV would also charge through the existing cables.

I'm looking at using the Heater/hot water compartment. I'm also thinking I could utilize the Solar-on-the-side lines for an easy solar hookup. 

I have one out at the pond moving water as sunlight hits those panels. That moves water to a container (uphill) with a small dc pump and that water I've used to irrigate with. With that I could a Proof-of-theory and buy another for the trailer.

I think you mis-understood.. I'm not going battery to battery. Converter output (the battery cables) to LiPo controller to Lipo battery. My dual 6v's are gone. Only the LiPo will exist. 

What worries me is the effect (if any) of grabbing the power source off the converter and sending it to another controller (the LiPo controller). I not seeing a conflict, does mean there isn't one, just not seeing it.

Maybe I'm mis-understanding something here.. Not like that hasn't happened before...

"Since current needs to flow both ways in the battery cables that would not be a good place for the solar charge controller. "

That's the part I thought would be a problem. The return side. Talking with a EE friend there is a way, yet becoming a PITA to make it work. For $180 it's probably better to just get a Progressive Dynamic's unit. 

"You will also need to disable your tow vehicle charging circuit"

I'm hoping to be emailed a wiring diagram for the PD unit I'm looking at. I have always assumed the TV charging/power goes through the exist WFCO controller. If I go PD, would not that still be happening? 

Going to bring my LiPo over to my EE friend and let him have a closer look. It has a built in charger/balancer. We'll open it up and he'll have a closer look at it. He has some thoughts of how to implement this LiPo, yet he needs a real good look-see first. 

I'll get back to you after we meet up next week.

"The converter you have is not an actual lithium converter but will charge to approx.. 90 to 95%.  We do not have a direct replacement converter that is lithium at this time."

Do have to ask though... carefully mind ya... You on lithium now?

If you plan to remove the lead acid batteries, and the wfco converter, and the charge line from the tow vehicle (and will be aware that the monitor panel battery indicators will be useless now) and then add a lithium compatible solar controller and lithium compatible converter charger, all done to go full lithium, you really need a STRONG case for doing so.

If you have that in mind, then go for it. But be prepared to open up your wallet VERY wide.

I thought it was you I read about in another thread that has a portable lithium similar to mine. I use mine as I believe you use yours, auxiliary power, augmenting the house system. 

 I don't even look at those panel lights anymore, I think they are useless now, especially for battery SOC.

I'm researching a couple different ways of doing this with help of a EE friend of mine to see what's feasible without breaking the bank. I'm catching up to him in a couple days. My existing lithium may get used as a proof-of-concept and decide from there how to go. My hopes was to find someone that has switched over and how they did it. So far that person has not popped up.

It does look like PD makes a drop-in replacement for the WFCO converter that will properly charge LiFePO4 batteries.

https://www.progressivedyn.com/lithium-converter-replacement-units/ - https://www.progressivedyn.com/lithium-converter-replacement-units/

The model number to replace the WFCO converter is PD4655LIV (55-AMPS). It is available here:

https://www.ltdrvparts.com/searchquick-submit.sc?keywords=PD4655LIV - https://www.ltdrvparts.com/searchquick-submit.sc?keywords=PD4655LIV

Mine is not portable, I physically mounted the Battle Born lifepo4 battery and associated components inside the camper...there are still 2 lead acid batteries and all of their associated components present. 

The lead acid system makes sense for powering factory installed house loads, and with nothing else to do, they run those minimal loads just fine.

The lifepo4 battery powers any additional loads that I add, such as 12v fridge, 12v fans, inverter, ham radio, laptop, etc.

I supplement the system with generators AND a solar panel system, inverter, and even more batteries in the bed of the pickup. 

I have not run out of power no matter what I choose to operate or the reduced solar input from cloudy or rainy weather conditions. And the cost was reasonable, unlike a typical full-blown 100% lithium system.

We went through so much it's hard to explain.. Some of which, I shouldn't.. I have an extended warranty to think about.

Can he devise a circuit to do what I wish? Yes. Can he detail it so I can build and learn from it? Yes, he's done this before and have learned so much from him. The question became if it was worth it...

Past projects we have done together have been well worth the effort and result. This one seems to be, if the responses to the questions work, just buy the unit.

On the top of the list so far is the:  http://www.bestconverter.com/Boondocker-BD-1235L-35-Amp-Adjustable-Lithium-ConverterCharger_p_525.html#.Xa9i6y3MzOS - http://www.bestconverter.com/Boondocker-BD-1235L-35-Amp-Adjustable-Lithium-ConverterCharger_p_525.html#.Xa9i6y3MzOS

This is the Promax Boondocker relabeled as the Boondocker. Reason for this one over the other is the adjustments already built in. No other component required.

Next was my first found and do believe a good unit is the:  http://www.progressivedyn.com/specialty/inteli-power-pd9100l-series/ - http://www.progressivedyn.com/specialty/inteli-power-pd9100l-series/

I'm awaiting an answer to learn if adjustable or if you have to buy the 'wizard' to do so. 

Reviews so far are good on both. So I see it as a choice of benefit of which.

More to come as answers come in and I review with my EE buddy first. 

P.S. Don't bother going to WFCO with questions of any technical nature. You'll get better results here! Trust me and save the frustration. 

I know you said do not push... But dude, really.. How much power do you use in a typical day? 

Sorry, I missed this.

Your first link is what I was looking at from them. My post (I guess above now) links the unit I think is best suited for us. 

The second link is a 55a unit which I would wonder what that could possibly do since we only have a 30a system. You tell me, I'll listen.. Information aids to decision!

How shall I ask this?

Not much. That is the key to my using the word 'choose'...I CHOOSE to not use much power. So again, restating my previous position:

I have not run out of power no matter what I choose to operate...

In other words: I have enough power for everything I choose to use. 

With lithium iron batteries you need a compatible converter charger, a compatible solar controller, (if using solar) and a compatible B2B charger if you plan to charge lithium from your tow vehicle. (do not believe the marketing about lifepo4 being drop-in replacements...they kinda are but they kinda aren't. Like 'unlimited' cellular data)

You might have missed the part where I said, open up that wallet. 

Originally posted by GlueGuy Originally posted by StephenH Since the unit that comes with the RPod is a 55A unit, I gave the number for the equivalent PD drop-in replacement. The 'Pod's AC circuitry is 30A, but the DC side is not the same. The 55A output is DC which is over 300A DC. The converter does not draw nearly that in AC amperage to output the 55A DC. Your EE friend should be able to explain this better than I can.  Other way around Stephen. 55 amps DC pulls about 5.5 amps on the AC side. (that is an approximation)

Thanks. I messed up my calculations when I wrote that. You said what I meant to say. I was thinking that if the 55A were the 120V AC, it would be over 300A DC. It is better to put it in terms of what the actual AC draw is to generate the 55A (maximum) DC output.

Guess have two different WFCO's. Mine's a 35a max. WF8735

http://wfcoelectronics.com/product/wf-8735-35-amp/ - http://wfcoelectronics.com/product/wf-8735-35-amp/

My max DC out (by fused circuit) is only 97.5a (dc) or 1219 watts or <11a (ac). These numbers exclude the reverse polarity fuse. Of course there is the potential of 336a DC, yet don't see that ever happening. 

I always thought it was the reverse polarity fuse, yet now wondering..

Edit: Since yours is a different model, I would look it up on the WFCO site to get a diagram that shows the location of the reverse polarity protection fuses.

Another edit: I looked and (now that I looked at the correct model), the bottom two fuses should be your reverse polarity protection fuses.

https://www.manualslib.com/manual/1235230/Wfco-Wf-8735p.html?page=3#manual - https://www.manualslib.com/manual/1235230/Wfco-Wf-8735p.html?page=3#manual

Thank you for the effort. 

Neither of those choices have anything to do with tow vehicle charging, they are ac source chargers only. If you want to do tow vehicle charging of a Li battery you will need another device. Here is one for example that provides a regulated dc output for Li battery charging and has dual inputs, one for solar and one for the TV 12V supply.

https://redarcelectronics.com/products/dual-input-25a-in-vehicle-dc-battery-charger - https://redarcelectronics.com/products/dual-input-25a-in-vehicle-dc-battery-charger

Yep, its expensive. The question is, do you really need to convert all three charging sources (TV, grid, and solar) or can you do with one or two? 

One point here is that Li battery charging is actually much less complex than PbA battery charging. There is no need for a complex multistage charging sequence. You just need to stay below the max charging voltage for your specific battery, which a dc to dc converter providing a regulated output voltage can do. But it is critical that you do that, there can be serious consequences (eg, fires) if you don't. 

There are any number of folks that have converted to Li house batteries in their RV's, just not so much in rPods. But that doesn't matter, the electrons don't care what kind of RV it is. A Google search will bring up lots of hits for this conversion.

Done a bit of research on these B to B units. I have a decent grasp on how they work now. What I'm reading is how well they recharge depends heavily on the SOC at beginning and duration. Certainly not a lone source for recharge.. 

We travel for months. Typically only staying put a few days. Currently (with my PbA's) I can go 3 days of real tough solar gain and catch the batt's up while driving to our next destination. I really don't wish to lose this benefit of TV charging. 

Sounds like you are mostly boon docking, like me. Then maybe skip the ac (WFCO replacement) charger and just use tow vehicle and solar charging?  That's my plan when I convert to Li. One nice thing about Li batts is that it doesn't hurt to leave them at partial SOC for long periods, which can be devastating for PbA's. 

Okay.. Biggest part of research right now is: How will you stop the WFCO charger? Or will you? 

I've read good points on both sides of the fence on this one...

Okay, I wasn't going to, but I guess I will... jump in the deep end of the pool..

It seems to me that the only reason to swap out the converter/charger is so the LiPo could get to full charge. That is for those that use shore power regularly. Now, for $180, I can switch out and have that opportunity and the unit is adjustable in it's ranges. Meaning, I can use my portable for now and upgrade later. 

As far as the B to B goes, we're looking at a circuit built up from modules that are easily purchased. I'll stop there for now until more is learned and worked through. 

I am also chasing 2 batteries right now. Nov 11th is the sale day for anything purchased out of China. If you know what you want (which I hope I do at that point), watch for a deal! Actually watch that whole week.. splash deals come and go quickly. 

I'm researching the Companies now. 

  

I plan to just remove the wfco. It will not be needed. 

I want to go with a 24Vdc Li battery, a 24V MPPT solar charge controller, and a 12 to 24V dc/dc converter from the TV. I'll have a small 24 to 12 Vdc converter to run the existing 12Vdc loads in the trailer, and a 2 to 3 kw 24Vdc to 120Vac inverter to run the heavy a/c and microwave loads. Everything is more efficient and you need much less copper conductor at 24V, and there are great deals available on 24V battery packs from wrecked Teslas. 

If I have 120Vac grid power available I can run the heavy loads directly on that. The 12Vdc loads are so small compared to the system I want to install that I don't ever expect to need to charge from the grid for that anyway. The solar will take care of it. 

Seems I could run with a 12V 20a unit. If I place the efficiency at 80% (wiring, unit, etc..), I'm looking at 16amps now. Is that a good assumption? 

Then I'm curious if indeed I will get the 16amps continuously. What can you really expect over a 4 hour period? 64amps (using my 16a assumption)??

If any of this is even close, then I may also just dis-connect the WFCO, actually mount a switch so it could be switched back over. 

Wiring losses don't effect current, they result in voltage drops so that shouldn't reduce the output current. The wiring losses show up as a lower voltage at the Li battery terminals than the output voltage limit you set for the converter. I would just use as large a wire gauge as will fit on the converter terminals and try to keep the wire runs short. So, at 20A 4 hours runtime ought to give you 80 amphours. But 4 hours idling your TV to recharge your battery while camping is a long time. 

My daily usage (at max) could be returned in a hour! The worst I hit (2 runs back) was down 700+ watts and it was still rain in our future, for a couple more days. Believe that was over 4 days. We packed up (time to head out anyway) and charged up on the drive (mostly). That's how I usually get recharged, solar or TV. 

From what I have reading/learning and what you stated of our B to B is direct, it seems beneficial to mount one of these charger units, anyway. I see several can be set for PbA, Gel, Agm or Lithium's.  

For me since I want to run about 80A I'm going to have to install a dedicated high capacity circuit and connectors between the TV and the trailer.  

I'm looking at the Renogy 12/12 20amp charger. For right now I may use my small lithium battery (38ah) or just buy something over the winter in the 60-100ah range. Size will depend mainly on pricing (deal). 

I am assuming right now that the 7 pin wiring goes all the way to the panel. I do now there is this auto breaker (and buss bar?) located under the Rpod up front. Could this be a location to tap in the 12/12 charger? 

I've never traced out the routing of the TV 12V circuit from the connector to the panel, but it doesn't really matter where between the trailer connector and the panel you place the b2b charger. as long as the charger is regulating the TV battery voltage before it gets to the Li battery. The shorter the conductors in that circuit are the less resistance losses you're going to have.   You could even locate the charger in the TV between the battery and the trailer connector if you wanted to.

Correct, the thought is I find the junction and splice in before the panel. I have to say I like the idea of putting it in the TV before the pin connector! Yet another reason I ask such things! Thank you

If this helps when I installed solar on my 179 last fall and the 179 is a 2019, the TV charging wiring going through the 7 pin connector was wired directly to the + side of the 12v trailer's battery.  Hope this helps.  Depending on where the WFCO convert is located, mine was in the back of the 179 by the entry door, and the + lead from the convert to the battery was one direct wire but the - lead was wired to the frame by the passenger side trailer wheel and then taken from the frame near the battery box to the - side of the battery.  Just some more incidental information.

Have fun,

Jay

Interesting.. Mine has only the main battery cable & the Solar-on-the-side line. You have a third? I know there is a buss bar (of sorts) near the auto-fuse underneath the camper up front. My thought is this may be where the 7 pin wire goes. That auto fuse does go to the battery.. That's the first place I hope to trace.

Another wet day today, so won't get out there to trace lines today, even with the power dis-connected.. 

This is where I tapped in the for the inverter I had in there before. I already have the hole/grommet to run the wires. I was hoping for this! This will place the Dc/Dc charger up by my water heater and right where I hoped to place the lithium battery. 

Rain has let up, so I'm taking advantage while I can. I'm updating as I print out the pin positions to ohm out the 12v line.

This is the mess underneath with the splices and auto fuses.

Top and right top is the 7 pin line from the TV to the splices above.

This is the 12vdc line from the 7pin 

Here the same line heads back towards the panel. Those two Red lines above are returns.

The two return reds now connect to the auto fuse.

Out the other side of the auto fuse and onward to the battery.

.  

Now for the decision of where to tap in.. 

To keep in mind here.. I'm going to dis-connect the Converter/Charger, it will not longer be part of the system. With that said, I still believe I can tap into the 7 pin splice. If so, this could be very easy as I would only need to re-route the battery cables and connect up the lithium battery. 

Thoughts???

Flow Chart

Just a couple of suggestions. 

If you place your solar charge controller in the same area then you'll have all your power electronics in one place. 

If you add a battery monitor that actually clocks amphours in and out you will have a way to monitor true battery state of charge on that expensive Li battery to replace the crappy lights that won't work for Li anyway. if you do, get one that uses an actual inline current shunt not a hall effect donut, those drift a lot. 

Thank you for responding, I was awaiting you! 

As I sit right now, I've been able to recharge the PbA's (dual 6v's) and run the Frig (on battery) while driving. That tells me I have enough amps coming through to maintain. I no longer battery run the frig while driving. I find propane to be so efficient, inexpensive and easy. Now the system just has to re-charge the batt's. System is good and TV power is good (not all can state that).

Question becomes:What have I missed here? I'm not asking to draw anything greater than what I have already and use. 

Question is: Am I tapping in at the right spot?

I 'think' I am... 

Current transformer donuts ( CT's) work fine for ac circuits because their magnetic fields are continuously varying in a known way. But they can't measure the static magnetic fields in dc circuits. Hall effect sensors work on a different principle, are much more fussy, and are sensitive to external stray magnetic fields.  That's why a simple current shunt is much more reliable for dc measurements.

I don't think you've missed anything other than I suggest you get a good understanding of what the BMS in your Li battery does and doesn't do. It needs as a minimum to do cell balancing. Some also provide a backup max voltage cutoff, and some also have a thermal cutoff. If yours doesn't have those features, depending on your risk tolerance you might want to add them externally, Victron for one has a product that does that.  Consider that you will be sleeping on top of this battery which could catch fire if it ever gets seriously overcharged...unlikely but not impossible...

Is that not what the Auto-breaker is? The real dusty module you see.

I'll be getting to the panel hopefully later this week, with this off & on rain it's been tough getting anything accomplished outside.. I want to see just where and how the hot wire from the pin ties in and how the WFCO is tied in. That will help with decisions of what & how I proceed.

I have say OG, shutting off the breaker sounds far too easy! Nothing is ever that simple.. LOL

Now, I have read some pretty good arguments that there can be logic to chaos.. One of those believers wired my trailer! What a rat's nest of wires! 

Worst are these two wires.. If anyone can identify, please do..

This one comes out of the DC side of the panel box. End is flatten like it was connected to something..

This one looks like it comes out of that red whatever (some sort of fused splice I think) but it actually passes under that and runs back into the abyss of wires.. Again, flatten end like it was connected somewhere.

Next is what I believe to be the Converter charger return. And yet another of those auto breakers hidden away never to be found by the average consumer.. 

In that last picture you see two wires on a side and the single that is running the the panel box. I need to ring both these out, but I think this is the 7 pin and the battery cable meeting up. If this is so, it explains another fuse here before the panel. And if indeed so, that makes the DC side 30amp max, at least from TV or battery. 

Lastly, I was hoping to find the Converter/charger was a separate unit from the panel. Not going to be that easy.. It's integrated. I'll read some more on the repair to the WFCO that another member (here?) posted and possibly reach out to see if a switch can be installed. A bit more time required on this part.

Most important right now is if anyone can identify those loose wires?

Yes, there is a fuse between the 7pin 12v (#4 pin) and the rPod battery. And yes there is a fuse on the Solar-on-the-side line. Both enter the 30a auto-breaker (underneath, Portside, fore) just before the battery. Well, at least on my 2017 182g they are.

There is also a 30a auto-breaker prior to the panel where the #4 12v line and the battery cable meet. 

Here's my chart.