LiFePo4 "upgrade" in progess.

[rickst29]

After most of the installation (yesterday in the driveway), everything works well. I used the two Amazon "power distribution blocks" which I had on hand to make 3-way connections into (and behind) the WFCO panel, as follows:

12V DC "Hot" side:

• 1 wire (small) from the PD "Wilkat" Converter;
• 1 short #8, into the DC Distribution Fuse Board "main power in" 12V terminal..
• 1 very long wire #6, going into LiquidTite Conduit (under the Trailer Floor, and within the Curbt-Side "box frame".

The #6 battery cable needs a bigger fuse than the 60A which I bought (The PD puts out more than that). I bought an 80A replacement. LiquidTite conduit comes out of the "box-frame" through a bottom corner of the inside holes for Torsion Bars on the two ends. Liquidtite is very resistant to compression, and protects the thin wire insulation for torsion bar abrasion.

Liquidtite is held in place using plastic clamps, with stainless screws into the TM flooring. After weather begins to cool down, I will seal entry points using 3M Boat Sealant #4200.

DC "Ground" side:
Rather than another long wire (with conduit) going to the new battery storage area, I connect the TM ground wires together in a tricky way. In my 2619, the TM "12-VDC Ground" Bus *AND* the 120V "Green Safety Ground" Bus EACH connect to the TM Frame using a length of #8 wire, both clamped in near the rear corner street-side lift. (Within a plastic box, screened to prevent water form collecting there.) Each #8 is good for 40A - not enough to handle the return load on the PD-to-battery connection, but the two (together) can handle it all.

So I used my other On-Hand "power distribution block" to connect 3 wires: The PD "12V ground" wire, a new #8 wire into the "120V Green Safety" Bus, and a new #8 wire into "12V Ground Bus". When PD puts out more than 40A of 12V power, some can use the '12V Ground Bus' and its link to the frame. But, about half of the total current returning from the battery "negative" terminal will reach the PD through the '120V Green Safety' Bus - connected with a return path of nearly identical lengths of #8 wire as the '12V Ground Bus' path from the frame.

Going from the Battery *to* the frame, I used another length of #6, and clamped it in where TM originally installed #8. (Length is short, not disturbed by Torsion Bars, and wire as at Ground Potential - so I did not use a conduit on this one. Conduit would tend to collect water, and I did clamp it against the TM floor to prevent catching on ground debris.
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I moved the big Breaker into the +12V side of the battery ,where it belongs. TM is now back in the garage, awaiting two more Power Distribution blocks for use at the "battery" ends. (In addition to the #6 wires, each will connect 2 wires @ #2, one into the battery (via "big breaker" on the plus side), and one into the Inverter.

[adventurefanatic]

Thank you for all of your posts Rick. Since I have almost zero electrical experience, would you be so kind to explain this to a dummy like myself? We are looking at a 2020 2720QB. We definitely want solar, but we also want to switch out the factory battery to a lithium when it is time. I have a good grasp of the solar part. It is the lithium that has me confused. Will I need to upgrade some components of the WFCO converter to install a lithium battery, such as a Battleborn 100Ah LiFePO4? Will I need to have the PD4655 MBA WildKat installed when we get the lithium battery? Even if it is not 100% necessary, is it still recommended to protect the investment? I would get a professional to do the work, since I am a dummy! ty

[rickst29]

But it's only the Power Converter 'section', inside the bottom compartment of the Unit. (The upper left "120V Section" with circuit breakers can remain intact, and the 12V power distribution section can also remain intact).

The WFCO Converters don't put out the required Voltage (14.6-14.7V) in "Bulk" mode. They also don't stay in Bulk mode for very long, falling down to "Float" mode far too early. BattleBorn guys love the WildKat - the live in my town, and I asked them.
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You MUST have high Voltage for these batteries, so that the BMS can create balance between the cells at the end of charging cycles. 14.5V is marginal. 14.6 to 14.7 is optimal for most types of BMS, although the Trojan "Trillium" batteries can handle 14.8V.
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But switching to one of these batteries will create a problem. (A 22-foot long problem in my 2019 model, probably much "smaller" in the 2720 which you're looking at.) The standard TM wire which connects Battery String to the +12V Power Distribution Board is only AWG-10, and good for only 30A.

LiFePO4 batteries have very low internal resistance, and they will like to be charged hard. My Battery will pull everything which the "WildKat" can put out. The WildKat protects itself from overloads really well, and limits output current to a about 64A. (Yes- 64A, not the 55A rated output.) So you really need AWG-6, THWN-2 wire to support load which the battery(s) are free to put on the the Charger.

In my 2619, I needed to pull a new cable of about 22 feet for "+12V" into he battery, and other new, big cables for the Ground connectors (into the frame). TM used #8 on the ground cables, and they also need #6 or better.

[adventurefanatic]

I really appreciate your explanation. Your reply presents a new question in my mind. When I contacted TM about pre-wiring for solar, they stated that "pre-wiring option" includes exterior wiring gauge of my choice, in addition to 10-gauge from the battery compartment to the sink cabinet (which I probably don't need if I place the solar charge controller near the battery).

If we want to upgrade to lithium once the factory-battery is at end of its useful life (and consequently have the WildKat also installed with the lithium), would it be advisable then to see if we can special order the TM with the larger 6-gauge that you stated would be required? Are we talking about three 6-gauge cables from the battery compartment to the WFCO, in lieu of their 10 and 8-gauge standard? My goal is to make the lithium upgrade easier later, since it seems technology is headed in that direction. Please forgive my elementary electrical knowledge. ty

[rickst29]

Originally Posted by adventurefanatic

I really appreciate your explanation. Your reply presents a new question in my mind. When I contacted TM about pre-wiring for solar, they stated that "pre-wiring option" includes exterior wiring gauge of my choice, in addition to 10-gauge from the battery compartment to the sink cabinet (which I probably don't need if I place the solar charge controller near the battery).

Their plan is for one or two solar panels (~100W each) on the rear shell, and it's a good option for that. Their exterior wire should be 10-AWG Solar Wire, with MC-4 connectors at the rooftop ends.

However, if you want to go bigger than 200 watts, you will need to use the front shell instead. The "sink cabinet" inner wire location is still good, but you will need to specify that the exterior wiring should be run up the rear of front-shell lift arms (rather than a rear shell lift arm).

Originally Posted by adventurefanatic

If we want to upgrade to lithium once the factory-battery is at end of its useful life (and consequently have the WildKat also installed with the lithium), would it be advisable then to see if we can special order the TM with the larger 6-gauge that you stated would be required? Are we talking about three 6-gauge cables from the battery compartment to the WFCO, in lieu of their 10 and 8-gauge standard? My goal is to make the lithium upgrade easier later, since it seems technology is headed in that direction. Please forgive my elementary electrical knowledge. ty

It costs them very little to upgrade to #6 (or at least #8) - and it can save you considerable time. I don't know the 12V ground wiring method for new TM models. Perhaps, like Airstream, they have switched from using the frame for "return ground" and now run grounding wires for the 12V "-" return wiring. In my model year, 12V "grounding" between the load center "ground" wires and the battery "-" terminals was done through the frame. 3 cables were installed: +12V between the load center and the battery "+" (size 10 AWG); a grounding neutral between the WFCO 12V neutral bus and the frame ((IRC, this was 8 AWG); plus another grounding neutral between the Battery "-" terminals and the frame (8 AWG, into another frame brass lug screwed into the frame). Pulling new wires was risky, so I kept theirs (but arranged to use both of them, together).

Per Post #10( https://www.trailmanorowners.com/for...2&postcount=10), I used 4 terminals blocks in my installation. Output wires from the WildKat Converter are connected into two blocks behind the WFCO Converter case (one for +12V, one for 12V "Ground"). The +12V terminal block has one wire back to the "Power Distribution" circuit board with fuses (IIRC, it's terminal lug could handle #6, and that's what I used). The other wire also #6, goes under the trailer in liquid-tite flex conduit, forward to the new "battery compartment" in storage under a couch.

The new "-" Grounding Block is done with complicated tricks: In my TM, there are two frame lugs for the WFCO: One connects an AWG-8 wire to the 12V grounding lug (full of white wires for 12V ground connections). The other connects an 8-AWG to the a frame lug for the 120V safety "grounding" bus (the green and bare wires). The two connections make the TM frame, 12V grounding bus, and 120V safety grounding bus a common ground.

My grounding block has: the original wires (both #8) from the frame lugs. It also has new and shorter #8 wires into the two WFCO lugs, with the 5th wire connecting 12V "-" from the WildKat. At the Load Center, I now have two "shared" wires into the frame, both serving both buses (the 12V grounding bus, and the 120V safety grounding bus). The dual #8 wires have about the same capacity as a single #6.

I cleaned the frame lug at the battery end (it's up front, on the A-frame in a 2619) and put in a new #6 to handle the battery "-". As I did at the WFCO end, the battery has new terminal blocks + and - . But they're larger ones, because each holds #2 wires for the battery terminals and the 120V Inverter connections.

[adventurefanatic]

I was thinking just a couple hundred watts is all we'll need - so I was thinking the rear shell would work fine. Currently, they are only offering one smallish monocrystalline panel factory-installed, which I why I wasn't certain about them doing all of the solar wiring. I'm not certain if it's an all-or-nothing "pre-wire option." It occurred to me to install the solar controller near the battery compartment and only run the cable for the LCD display to the interior. By their reply, it seems they pre-wire 10-gauge to install the controller below the galley sink.

Since I've never had technical experience with the TM and since I easily get lost in the detail with my shortcomings in regard to the electrical system, I am thinking I should propose my desire for lithium (at least later) to TM and see what they say. It's really hard for me to conceptualize in detail what I haven't seen or experienced, though I re-read what you wrote several times.

I am curious if TM has any plans or ability to install the correct system components at the factory to make the upgrade with a drop-in lithium replacement possible... Rewiring the components down the road seems like it would be costly rather than factory-installing, especially since we would need a professional to do the upgrades. I also would feel more comfortable knowing it is done by the manufacturer than at a dealer. Since technology seems headed toward lithium, I'm really hoping TM has been considering this, though maybe the demand isn't there. Thanks again, this is a lot of food for thought. I think I'll contact TM and see what they say.

[rickst29]

Because a "proper solar installation" of 200W (or more) should use panels wired in series: The Voltage multiplies by the number of panels, while the current remains constant (at the operating values of just one panel). #10, or even #12 wire is fine when you are only moving 6A of current. IIRC, my own Solar wire connections are #12, running less than 6A @ 65V(mp.)

I would not expect TM to have any interest in Lithium upgrades at this time, nor to spend lots of extra money upgrading the Power Converter in ways which hardly anyone will notice. Even Airstream has been selling their (very expensive) Trailers with WFCO converters.

[adventurefanatic]

I suspected I have been overthinking this and that there is little market for the manufacturer to consider. In the end, we will probably opt for the solar pre-wire option, install a couple hundred watts, use the factory-standard battery, and leave lithium considerations for a future time. I do sincerely appreciate your willingness to offer your knowledge and experience.

[rickst29]

Edit 6/19/2020: All +12V wires from the 12V 'power distribution connector' now have circuit breakers (even the tiny one going into the battery monitor). These older pictures include smaller 'power distribution lugs' than I now have, and don't include the second battery - but they're otherwise still valid.

Don't read this text first - look at the pictures, and then use the text for detailed explanations.

First picture: First, here is the big battery (in living space, under a table-side couch). Photo taken before lugs and connectors wrapped in electric tape. The "+12V" Power Distribution supports 6 connectors (one being used by the battery, 5 "downstream"). A large 2-AWG wire with a 200A Circuit Breaker goes into a 120V inverter (1500w continuous). On 6/19/20, I changed this breaker from the pictured '150A' breaker, because the new one can clamp in the #2 bare wire ends more firmly than the 150A could screw down ring terminals. Operating current for the microwave is about 100A, but the new and superior circuit breaker wasn't available in a 150A model.

A moderately large wire goes through an 80A Circuit Breaker, and connects to a smaller, 3-way Distribution Block behind the Converter Panel. This runs the entire TM. From the 3-way distribution block, one leg goes to the new PD Converter Unit (A Lithium-Compatible "MBA Wildcat"), and the other Leg goes to the WFCO 12V Power Circuit Board (with all the fuses). The 80A circuit breaker also serves as a battery shutoff, relative to TM "phantom loads". This wire (AWG-6) is routed under the trailer, in liquidtite conduit, with clamps attached using stainless steel screws. The wire never carries more than 65A to the battery (from the "Wildcat"), and should never need to carry more than about 30A from the battery to the circuit board.

Back on the "battery" 12V power distribution block, another moderately large wire (AWG-8) comes from the Solar Controller. 40A circuit breaker added on 6/19/20.

A smaller #10 wire goes to a new "12V power port" underneath the Street Side front corner of the Trailer. 30A circuit breaker added 6/19/20. And the last port is taken by a very small wire which runs the "coulomb counter" battery monitor, after the 6/19/20 rebuild it also has a 20A circuit breaker.

The negative side looks complicated, but it's simply a shunt for the coulomb counter monitor (monitor not shown), and 12V Grounding current connectors - including a new and bigger frame connector, for the negative ground bus back at the 12V distribution panel.
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The second photo is the street-side front, showing the new 12V power port underneath. TM gave us 120VAC outlets, but no 12V. When the spare tire needs inflation, this will come in handy.
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The third photo is my new and simplified "dual input switcher" for the Solar Controller (AKA the "Stockton Boost Device"). The Solar Controller is an EP-Solar BN-3215 with an MT50 "monitor and display/control" LCD Unit. First notice that *three* wires come in from underneath the floor. Two wires are "+" and "-" from the Solar Array, but the 3rd wire is "Trailer Battery Charge" from the 4Runner TV.

Two 3-way Connectors are used. One splits the "Trailer Battery Charge" into two leads, and the other splits a "12V Negative Ground" connector. This now the only termination point for 'Trailer Battery Charge', which is capable of providing 540 Watts (36V * 15A) from the 4Runner on-the-fly, using a dashboard switch. Only one relay is present: A 5-pin Relay with a 36VDC coil voltage. One of the "Trailer Battery Charge" wires goes into a switched POWER terminal (Normally Open), while the other one drives the coil. (One of the two 12V Negative Ground wires connects the "-" coil terminal, the second connects Controller "battery -".) The Solar Array "+" lead goes into the 'Normally Closed' Power terminal. The Common Power lead goes into the BN-3215 "Solar +" terminal. (Those three "Negative Ground" Connectors are also linked to the "Battery -" connector wire, within the BN-3215.)

When "Trailer Battery Charge" has only 12-13V (or nothing at all), the actual Solar Array is connected to the Solar Controller. But, when I flick the "magic" switch in my 4Runner, "Trailer Battery Charge" is boosted to 36V. The Relay coil is pulled in by the 36V Voltage, and the power input Relay terminals disconnect the "genuine" Solar Panels, and connects the "Trailer Battery Charge" connection instead. The common output goes into the Solar Controller "Solar Array +" terminal.

From the 4Runner, my regulating "Boost Converter" can put out 540 Watts (15A @ 36V). Under the best of conditions, my genuine Solar Panels can only put out 370 Watts - and that happens only at Solar Noon on a cloudless day in early summer. The 4Runner boost can run under clouds, or at night, and deliver more power all the time. I normally flick the "magic switch" to 36V at all times, as soon as reaching cruise speed, when towing the TM.

The maximum output of the 30A Solar Controller is only about 440 Watts @ 14.6V. With various inefficiencies along the path, it could pull (maybe) 500 Watts form the boost converter. But, at 36V, that's less than 14A, and easy for the Bargman and Relay to handle. The genuine Solar Panels have even higher Voltage (about 65V), and less than 6A of maximum current.
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The fourth and fifth photos are my mounting point for the new PD "Charged Wizard", and the 120-VAC breaker panel. I added a new Breaker, so that the PD Power Converter can be disabled in isolation from everything else. That helps to prevent "loops" in which the Inverter creates 120V power from the battery, but the Converter turns around and wastes trying to recharge the battery.
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The last photo shows my MT-50 Monitor, pretty happy in spite of a rainy and cloudy day with lousy Solar Power production.
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Not shown: remote 'power on' for the inverter, and the safety-enhanced "suicide connector" for plugging the TM outlets into the Inverter. The safety enhancement is simply a 120V-15A socket with no wire attach, covering the pins of the otherwise hot-when-plugged-in-at-a-campground "suicide connector" 3-pin 120V plug.

In my scheme, turning on the Inverter, by hand, consists of a 3-step process (after you're positive that you are NOT plugged into 30A campground power, and have lifted the couch seat and storage "cover" board):

1. Pull the "Suicide Plug" out from it's safety socket adapter, and plug it into a (still not turned on) Inverter output socket;
2. Turn on the 200A circuit breaker;
3. Turn on the Inverter.

When done using 120V, I reverse the steps. For intermittent multiple uses in a boondock, I can simply use the remote Inverter power switch (step 3) to turn it on and off, leaving the "suicide connector" plugged into the Inverter until I break camp.

[rickst29]

Cutting #2 wire segments is kinda hard, and crimping on "ring-type" terminal lugs requires a special tool: https://www.amazon.com/TEMCo-Hammer-...dp/B00E1UUVT0/. (Insert the connector, push the wire into the connector, and then hit the raised 'head' with a sledge hammer a couple of times. (Very gently, if a 4-lb or bigger sledge.) Then solder them up.