Tapping 12V from the truck to charge Battle Borns

[howson]

Are you changing your mind on disconnecting the 7 pin charge line?

Your question leads me to think I didn't convey my point very well. I am absolutely not going to connect the 7-pin charge line. For me it does next to nothing, so why connect it? I know for sure there's no chance of backfeed through that positive wire with it physically disconnected. Since you'll also have a 40A DC-DC Charger, it's difficult to understand why it's even a consideration to modify the truck's wiring by adding a diode. All that does (IMHO) is open up the possibility of a warranty being denied due to "customer modification".

My .02: either leave it as is (truck will not backfeed as configured--at least my '17 does not) or disconnect the wire since the DC-DC Charger setup does the same job but far exceeds the 7-pin's OEM capability.

Appreciate you allowing me to chime in...look forward to your future reports no matter which configuration is installed.

[Yoda]

howson

Thanks Howard.

If I put the diode in it will be on the trailer wiring - not the truck. I have other trailers that use the charge line to keep the break away battery charged. Only truck modification planed is adding a stud to the drivers side positive terminal. That way the DC-DC wiring run is a straight shot. There also appears to be a good place for the inline solenoid that will control it. I just haven't looked at that project yet.

I just installed my EasyStart - not two bad . Will do the learning curve tomorrow. Right now reviewing the several install videos to make sure the wiring I did is correct and waiting for the rain/lightning threat to pass.

Edit
BTW Howard. It was my mistake. I misread your answer in post 143. My mind had it reversed - sorry I'll go to my corner of shame now

Keith

[Popga]

howson Howard, it almost looks like the AM solar statement is a giant CYA. This is to keep people from not installing the proper negative wire to the charger. Also states that by pulling the negative wire from the 7-pin may cause the trailer lights and other systems to not work correctly.

Wonder if someone could 3d print an anderson housing with a set of contacts that open when the plug is inserted to break the negative in the 7 way.

howson

Howard, you did not disconnect the negative wire on the 7-way, only the 12V, Ya?

Erik

[howson]

howson

Howard, you did not disconnect the negative wire on the 7-way, only the 12V, Ya?

Erik

Yes, only the +12v charge line on the trailer side. See the final schematic in post 147 and the notes in the diagram.

I'm going to leave my setup alone (it works without any known issues) but as has been documented in other installs since mine, there doesn't appear to be any downside to leaving the trailer's OEM +12v charge wire connected.

While I don't disagree with what Garret stated (it's theoretically possible for the DC-DC Charger to use the truck's 7-pin negative as a return path) I agree with Jlawles2's subsequent analysis that it's little more than CYA. Since AM Solar is a business I guess it's what he must write.

[Budwin]

I'm just adding a 30A fuse on the 7-pin negative wire in the trailer connection box. (to protect that wire)
This is overkill since the charger 4ga negative wire and the trailer ball to truck connection would have to both fail in order for a high return current to appear on the 7-pin negative wire.
The chances of the #4 red wire being connected without the black being connected is what I would call VERY unlikely. (even then the ball/chain to trailer connection would shunt the high current)
An oddball and unlikely event where that 4 ga black wire becomes high resistance and the 7-pins ground gets more and more current, would be hard to detect in some circumstances. (7-pin wire heats up)

I see no down side to adding the inexpensive fuse to the 7-pin negative for extreme CYA. (there could be a reason not to do add it I'm not thinking about though)
Disconnecting the charge wire, no need for it.

[howson]

I'm just adding a 30A fuse on the 7-pin negative wire in the trailer connection box. (to protect that wire)
This is overkill since the charger 4ga negative wire and the trailer ball to truck connection would have to both fail in order for a high return current to appear on the 7-pin negative wire.
The chances of the #4 red wire being connected without the black being connected is what I would call VERY unlikely. (even then the ball/chain to trailer connection would shunt the high current)
An oddball and unlikely event where that 4 ga black wire becomes high resistance and the 7-pins ground gets more and more current, would be hard to detect in some circumstances. (7-pin wire heats up)

I see no down side to adding the inexpensive fuse to the 7-pin negative for extreme CYA. (there could be a reason not to do add it I'm not thinking about though)
Disconnecting the charge wire, no need for it.

You're a trailblazer as I can't recall anyone else adding a fuse on that line. Please post back with the results (good or bad).

Howard

[Jlawles2]

Budwin One thing to note is that fuse should be readily visible for inspection. As you mention there are numerous paths for the negative to follow, however from personal experience of failed negative wires in connectors, the non planned paths can create havoc on the lights (such as both flashing when only one selected).

[Jomani]

Wow - what a great thread. Just read through all 12 pages and love the evolution.

I am currently down following shoulder surgery surgery and have been doing a lot of planning, reading and shopping. I have already acquired the following:

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Joe's full post is now here: https://gdrvowners.com/forum/operati...pgrade-project

[TucsonJim]

Resurrecting this thread.

Once we get our new Solitude delivered, I want to install a DC-DC charger. I know this thread focuses on Renogy. But the Victron Orion 30 amp 12V DC-DC chargers are now available. The Orion can be programmed via the Victron app to sense when the truck has started (if equipped with an alternator that is compatible). So no voltage sense wire is needed.

I already have 2 AWG wired to the bed of the truck that I used to power my motorized boat loader in the past. So it should be a simple task to tap off the 2 AWG supply to provide power to the Orion and charge the new LiFePO4 battery bank.

Another nice feature of the Orion DC-DC charger is that you can use the Victron App to select pre-programmed charging profiles or build your own. Where-as the Renogy has DIP switches that are used to select the charging profile.

If you have a 12V tow vehicle and a 12V RV, you'll want the Victron Orion-TR 12/12 30 amp Isolated version. P/N ORI121236120. The non-isolated is for RVs that share a common ground such as a motor home.




Jim

[ncitro]

TucsonJim I was always unclear on the isolated vs not as the ground between the truck and trailer are tied together when you're hooked up. Through the pin/coupler, and the negative wire into the Bargman right? I preferred the Renogy for more power. With 2 gauge you could definitely run the 40A and maybe even the 60A Renogy. More power was more important to me than the app for short drive days.

[TucsonJim]

TucsonJim I was always unclear on the isolated vs not as the ground between the truck and trailer are tied together when you're hooked up. Through the pin/coupler, and the negative wire into the Bargman right? I preferred the Renogy for more power. With 2 gauge you could definitely run the 40A and maybe even the 60A Renogy. More power was more important to me than the app for short drive days.

I did a little more research, and found that the Renogy only comes in an "isolated" version. The only real difference is that you need to run a ground wire from the tow vehicle and the RV vs. just a single ground wire on a non-isolated version.

You can parallel two (or more) Victron units together which would give me the 60 amp charging capacity. That would also allow me to use the Victron app for programming. Of course that would drive cost up quite a bit more. But I can always try to convince Yoda to spring for it...

Jim

[Yoda]

I did a little more research, and found that the Renogy only comes in an "isolated" version. The only real difference is that you need to run a ground wire from the tow vehicle and the RV vs. just a single ground wire on a non-isolated version.

You can parallel two (or more) Victron units together which would give me the 60 amp charging capacity. That would also allow me to use the Victron app for programming. Of course that would drive cost up quite a bit more. But I can always try to convince Yoda to spring for it...

Jim

LOL - nice try I just ordered my OBA fittings, compressor, etc so I am broke for a while....but I did sell off some of my Hay equipment to cover for it.

The real questions is Ginnie in the loop - or dare I ask

BTW have you gotten the new unit yet? I assume something big and blue is being installed too

Keith

Also as a side note my 60 amp Renogy is tied both positive and negative directly with the truck battery - Anderson connection.. And the case is grounded to the trailer frame. I think that in my write up somewhere here.

[ncitro]

I did a little more research, and found that the Renogy only comes in an "isolated" version. The only real difference is that you need to run a ground wire from the tow vehicle and the RV vs. just a single ground wire on a non-isolated version.

You can parallel two (or more) Victron units together which would give me the 60 amp charging capacity. That would also allow me to use the Victron app for programming. Of course that would drive cost up quite a bit more. But I can always try to convince Yoda to spring for it...

Jim

I didn't find the programming to be an issue. Unlike the other gear it's a set it and forget it, I haven't touched my dip switches since I installed it. The shunt tells me enough to know it's on and working (I see my current increase by 40A).

[howson]

I did a little more research, and found that the Renogy only comes in an "isolated" version.

New topic for me, Jim, so I also did some reading here: https://www.alliedcomponents.com/blo...wer-converters After all the reading I'm left with this question:

Is there any electrical reason to NOT run an isolated version of a DC-DC Charger in a travel trailer or 5vr?

Since the Renogy is specifically designed to be used in RVs (as stated in their manual) this shadetree RV electrical technician thinks the answer is "no". (Someone set me straight if I'm off track.)

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MORE INFORMATION
There appear to be many advantages (as listed in the linked article) to an isolated version. Wiring schematic from the Victron manual for the isolated version:



The non-isolated version's wiring diagram (from the Victron manual) is more like how mine's wired since the trailer and truck are connected together.

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RENOGY VS VICTRON
Anecdotal, but I've had very good service from the Renogy 40A DC-DC Charger ($129). As I've often stated here on this forum, I'm an unabashed Victron "fanboy" , but the Orion 30A isolated version is almost double the cost of the Renogy ($254). Non-isolated Victron is $226. Prices compared using just Amazon as the source.

As Neil stated, monitoring the BMV-712 Battery Monitor provides the assurance the Renogy charger is working. As stated in this thread, I went with the Renogy based off of Will Prowse's review on YouTube.

Not trying to convince you either way, just summarizing my experience with the unit. Definitely can't go wrong with the Victron.

Howard

[Yoda]

New topic for me, Jim, so I also did some reading here: https://www.alliedcomponents.com/blo...wer-converters After all the reading I'm left with this question:

Is there any electrical reason to NOT run an isolated version of a DC-DC Charger in a travel trailer or 5vr?

Since the Renogy is specifically designed to be used in RVs (as stated in their manual) this shadetree RV electrical technician thinks the answer is "no". (Someone set me straight if I'm off track.)

---

MORE INFORMATION
There appear to be many advantages (as listed in the linked article) to an isolated version. Wiring schematic from the Victron manual for the isolated version:



The non-isolated version's wiring diagram (from the Victron manual) is more like how mine's wired since the trailer and truck are connected together.

---

RENOGY VS VICTRON
Anecdotal, but I've had very good service from the Renogy 40A DC-DC Charger ($129). As I've often stated here on this forum, I'm an unabashed Victron "fanboy" , but the Orion 30A isolated version is almost double the cost of the Renogy ($254). Non-isolated Victron is $226. Prices compared using just Amazon as the source.

As Neil stated, monitoring the BMV-712 Battery Monitor provides the assurance the Renogy charger is working. As stated in this thread, I went with the Renogy based off of Will Prowse's review on YouTube.

Not trying to convince you either way, just summarizing my experience with the unit. Definitely can't go wrong with the Victron.

Howard

Howard interesting reading.. I am not sure I understand the difference between isolated and non isolated even after reading the link, except the Isolated has 4 wires with s dedicated negative return to the battery. However in the Non-isolated circuit the charge wire and negative return wire in the 7 pin are being utilized as well as the trucks ground system how ever wired The possibility of overloading the trucks circuit seems a concern to me. Or I am reading things wrong - I am not an expert here, just a lot of experience letting the magic smoke out of the wiring.

From the link

Understanding Isolated and Non-Isolated Power Supplies


Isolation in a power converter: In this system, a transformer is used to physically and electrically separate the circuit into two sections. The current won’t flow between input and output due to this separation.

Non-isolated power converter: Flow of current between input and output is possible because there’s only one circuit.

Now I have a concern on how either circuit is wired per your diagrams . When I started my DC-DC project I took the wiring diagrams to my Ford service manager (both Renogy and Victron). He indicated that under no circumstances should I wire anything directly to the alternator, and only connect through the battery, otherwise the power management system is bypassed and the amperage draw could damage the alternator, especially if a short occurs. He indicated to always tie to the battery, or an up fitter switch as those are protected. Now maybe this only applies to my 2022 Ford as it has two alternators and both operate in parallel as providing power to the truck

BTW - I too can see its working by checking the BVM 712

So if I understand you question correctly you answer is correct - always run isolated chargers or other devices to protect the truck and trailer power systems.

Keith