DC to DC success - but a few lingering questions

[richard5933]

Originally Posted by dznf0g

So, that's 194*F. Just lay your hand on it, or hit it with a temp gun, when it is working hard (delivering a lot of current for an hour or so). If you can't keep your hand on the heat sink, use your discretion as to changing location or mounting material, I have mouse fur on my walls, so is that better than wood? My charging components are under the front couch in/on the electrical center with no top on the box. So pretty good ventilation.

My son's camper has all its components in enclosed compartment with two 3" X3" vents on a side wall. If I feel his compartment is getting too hot, I'll install a thermostatically controlled muffin fan for exhaust.

194F sounds like a pretty high temp, but I suspect that it's not much different than the temps inside a closed vehicle parked in the sun for a few hours. Put a thermometer on the dash of your car next time you park in the sun. My first car was a 1956 Dodge with a black Bakelite steering wheel. In Texas. In the summer. I remember getting close to doing damage to my hands holding that wheel getting off work in the afternoon.

On my Victron products there is an air gap between the bottom plate and the wall, where airflow can go. This is why they recommend that the devices be mounted in a way that puts the cooling fins in a vertical orientation and not horizontal if at all possible since it greatly helps with air flow and cooling.

[ITSNO60]

What sort of short circuit protection are some of you using on the DC-DC chargers? MIDI fuses? Marine circuit breakers? I'm going with the 30 amp Orion and trying to plan it out.

[JandB]

Originally Posted by richard5933

Mine is mounted to the interior skin using #12 stainless sheet metal screws. They hold plenty tight.

That aluminum turns out to be thicker/stronger than I anticipated. Even with the DC/DC and solar charge controller being ~3 lbs. each, the #12 screws tightened up nicely. I have no worry that they won't be there for years.

Thanks for the push.

[JandB]

Originally Posted by ITSNO60

What sort of short circuit protection are some of you using on the DC-DC chargers? MIDI fuses? Marine circuit breakers? I'm going with the 30 amp Orion and trying to plan it out.

In my case, I didn't add any fuse as I didn't add separate wiring from the TV. I used the existing 7 way wiring which is fused.

On the output side of the charger, the wires are -not long, only ~1 ft- (hate to say short when talking about wiring ) and there is a fuse in the distribution box that came from AS to protect the trailer.

[dznf0g]

Originally Posted by JandB

In my case, I didn't add any fuse as I didn't add separate wiring from the TV. I used the existing 7 way wiring which is fused.

On the output side of the charger, the wires are -not long, only ~1 ft- (hate to say short when talking about wiring ) and there is a fuse in the distribution box that came from AS to protect the trailer.

Likewise

[thewarden]

Originally Posted by dznf0g

I believe you will find that after a few hours driving, when the TV battery becomes saturated, that your alternator will drop to as low as 12.6v. Or turn completely off for awhile.

I believe, that if the OPs truck has tow haul mode, the charge profile of the smart alternator changes in tow haul to accommodate for trailer battery charging and that it will never completely turn off.

[dznf0g]

I have read that and that is supposed to be true.....on my 2015. But monitoring says it's not true, for prior generation anyway.
I can turn on and off tow haul, and there is no effect.

It could be a longer period of time, but it still cycles

[JeffKim]

Originally Posted by JandB

In my case, I didn't add any fuse as I didn't add separate wiring from the TV. I used the existing 7 way wiring which is fused.

On the output side of the charger, the wires are -not long, only ~1 ft- (hate to say short when talking about wiring ) and there is a fuse in the distribution box that came from AS to protect the trailer.

This came up in another thread to which I authoritatively responded that the charging wire isn't fused at least in our 2023 GT 25FBT. I haven't found one and in the wiring diagram there isn't one indicated. The charging wire is wired to the positive bus bar which is fused at the battery, but that's it as far as I can tell. Or am I confusing something?

[JandB]

Originally Posted by thewarden

I believe, that if the OPs truck has tow haul mode, the charge profile of the smart alternator changes in tow haul to accommodate for trailer battery charging and that it will never completely turn off.

Now that would be pretty cool, and "smart".

Still haven't gone anywhere so time will tell. Not sure if alternators have gotten any smarter since 2015, but this being a 2024, I can only hope.

[ITSNO60]

Another question for you all who have the Orion 12/12 DC-DC Charger. It is not 100% clear from reading the manual if the Orion can be switched off through Bluetooth. I see it can be switched off/disabled through the little green RS 485 looking thing a number of different ways but I haven't found if it can be switched off remotely with BT. I don't have the unit yet, just studying the online manuals.

[JandB]

Originally Posted by JeffKim

This came up in another thread to which I authoritatively responded that the charging wire isn't fused at least in our 2023 GT 25FBT. I haven't found one and in the wiring diagram there isn't one indicated. The charging wire is wired to the positive bus bar which is fused at the battery, but that's it as far as I can tell. Or am I confusing something?

This is what is in my DC distribution box.
Looks like a 30 amp circuit breaker. ?

[JandB]

Originally Posted by ITSNO60

Another question for you all who have the Orion 12/12 DC-DC Charger. It is not 100% clear from reading the manual if the Orion can be switched off through Bluetooth. I see it can be switched off/disabled through the little green RS 485 looking thing a number of different ways but I haven't found if it can be switched off remotely with BT. I don't have the unit yet, just studying the online manuals.

I just went out and played around with it and I don't see any "Off" setting on the app. So, no off via Bluetooth. Looks like that would have to be done with a switch through the remote L-H pins.
Maybe a future update will allow an off via Bluetooth.

[ITSNO60]

Originally Posted by JandB

I just went out and played around with it and I don't see any "Off" setting on the app. So, no off via Bluetooth. Looks like that would have to be done with a switch through the remote L-H pins.
Maybe a future update will allow an off via Bluetooth.

Thanks for checking. Running a wire is not hard, just need to find a good place for a switch.

[JandB]

Originally Posted by ITSNO60

Thanks for checking. Running a wire is not hard, just need to find a good place for a switch.

You're welcome. Curiosity was getting the best of me anyway.

Instead of a separate switch, you could find an ignition switched circuit, use that (putting + to pin L), and then on/off would be automatic.

[ITSNO60]

Originally Posted by JandB

You're welcome. Curiosity was getting the best of me anyway.

Instead of a separate switch, you could find an ignition switched circuit, use that (putting + to pin L), and then on/off would be automatic.
Attachment 438910

I plan to use the automatic "engine on" sensing ability for that. In addition, I will keep my Battery Isolation Solenoid in place and run the supply to the Orion directly from the output of the BIS, so I will actually have double assurance that the unit will be disconnected when the engine is off.

My reason for wanting to shut the unit off when the engine is running is for when we are approaching home and will not be using the rig for a while, I want to be able to store the lithium at 50-60% per the mfgrs instructions and this way I can run it to that level with the fridge in the last hours of the trip instead of arriving home with 100% and needing to waste/use up that excess before storing. I also don't want the Li to charge every time I start the engine, this is a Sprinter RV, not a trailer and there is the occasion where it will get driven around town a little.

So I can wire a switch to the terminals on the Orion or to my BIS, either way would do it.

[Keys Dave]

Maybe it's just me but has anyone else had a problem with the trailer running lights not working after installing the DC TO Dc charger. I found that the isolated ground caused the the lights to stop working. I had to jump from negative to negative on the charger.

[dznf0g]

Originally Posted by Keys Dave

Maybe it's just me but has anyone else had a problem with the trailer running lights not working after installing the DC TO Dc charger. I found that the isolated ground caused the the lights to stop working. I had to jump from negative to negative on the charger.

Where are you connecting the ground wire? (without that jumper)

[JeffKim]

Originally Posted by JandB

This is what is in my DC distribution box.
Looks like a 30 amp circuit breaker. ?

Thanks. Here's where the charging wire connects in mine (a picture I took a while ago). Is there a fuse under there? I can't tell. I'll have to pull things apart to look at it next time I need to get in there.

[ITSNO60]

Originally Posted by JeffKim

Thanks. Here's where the charging wire connects in mine (a picture I took a while ago). Is there a fuse under there? I can't tell. I'll have to pull things apart to look at it next time I need to get in there.

Looks like fuses.

BTW I have been researching this thing so much that when I was looking at your picture in post #14 I actually Googled "Marshmallow Skewers" thinking it was a slang for something related to the installation that I hadn't heard about

[JandB]

Originally Posted by JeffKim

Thanks. Here's where the charging wire connects in mine (a picture I took a while ago). Is there a fuse under there? I can't tell. I'll have to pull things apart to look at it next time I need to get in there.

That's it. Either fuse or a resetting breaker.

Fun getting that lid off with all the wires in the way isn't it.
Mine still isn't pretty but I had to move a lot to even get to the screws.