DC to DC charger from TV

[Bookemdanno]

I was looking for another project and was wondering if anyone has any input (negative or positive) on some of these chargers from the TV to the RV? I have dual alternators on my TV and was wondering if it would improve the power going to the batteries from the TV. I know that the 7-pin puts power to the batteries, but in a limited capacity compared to what it looks like these DC to DC chargers are putting out if you run thicker cables.

Something like this: https://www.etrailer.com/Battery-Cha...BCDC1225D.html

BUT...it's kinda $$$. Does the pros out weigh the cons?

For my set up specifically, I have residential fridge and one 100 AH 12 volt lithium battery. We have only stayed in parks with power, even if it's a 1 night stay over enroute to our final destination. I guess I'm just trying to gleam more insight with these systems.

TIA!

[ttavasc]

Originally Posted by Bookemdanno

I was looking for another project and was wondering if anyone has any input (negative or positive) on some of these chargers from the TV to the RV? I have dual alternators on my TV and was wondering if it would improve the power going to the batteries from the TV. I know that the 7-pin puts power to the batteries, but in a limited capacity compared to what it looks like these DC to DC chargers are putting out if you run thicker cables.

Something like this: https://www.etrailer.com/Battery-Cha...BCDC1225D.html

BUT...it's kinda $$$. Does the pros out weigh the cons?

For my set up specifically, I have residential fridge and one 100 AH 12 volt lithium battery. We have only stayed in parks with power, even if it's a 1 night stay over enroute to our final destination. I guess I'm just trying to gleam more insight with these systems.

TIA!

I'm actually in the process of adding this capability using a Victron Energy
Orion-Tr Smart 12/12-30 Isolated DC-DC charger. This one runs a bit less than the REDARC coming in around $260. I don't have dual alternators on my F-250 but I do have the heavy duty 200amp so this should work well with that. I'm also using a 85 amp continuous duty solenoid under the hood and tapping that into a fuse that is ignition-switched. I currently have a pair of Trojan T-125 GC2's with 240ah. I decided to add this now instead of roof-top solar as it will give me more flexibility on inclimate weather travel days. I do have 200 watt solar suitcase as well plus the 2kw generator. For my needs this rounds things out nicely.

[Jay2504]

Am I missing something? (Happens a lot more than I want it too). If the goal is to charge the camper batteries at a higher rate why not run a heavier cable from the TV battery to the camper, using a separate plug at the back of the TV, and a heavy duty fuse. Wouldn’t that be cheaper and easier? Jay

[ttavasc]

Originally Posted by Jay2504

Am I missing something? (Happens a lot more than I want it too). If the goal is to charge the camper batteries at a higher rate why not run a heavier cable from the TV battery to the camper, using a separate plug at the back of the TV, and a heavy duty fuse. Wouldn’t that be cheaper and easier? Jay

In my opinion there are a few reasons why the added expense of the DC-DC charger would make sense. Most modern vehicles use some form of a "Smart" alternator where the profile is primarily keep the starter battery charged in the most fuel efficient manner. That is a very different profile from what I want to use for a larger, and often a different battery type installed on the camper.

A quality DC-DC charger is multi-stage and includes multiple charging profiles such as FLA, AGM and Lithium. They can be set up to ensure that voltage remains constant to the camper battery bank as needed for the current charge stage regardless of what the "Smart" alternator is doing. This also helps with voltage loss due to the long wire run as well. I've also read of alternator overload issues due to low impedance of the Lithiums which is another scenario where a controlled charging profile is useful.

While my current battery bank is FLA at some point I am wanting to move to Lithium so from my perspective this is just part of laying that foundation to ensure any charging capability I use is designed specifically for the type of battery bank installed in the camper.

[Bookemdanno]

Thanks for the input...I just don't know about cost at this point. I'm wondering if I should wait until the cost comes down after a year or so? I know this is relatively new technology, so maybe the costs will come down with time. I'm all about "bang or buck"!

Edit: Maybe I'd be better off installing another Battle Born battery?

[ttavasc]

I haven't finished collecting all the parts to complete my installation but I'm estimating the cost will likely be around $500-600. Another Battleborn will run about $950 I think. In my opinion though cost isn't necessarily the deciding factor. If all you are looking for is a little bit of extra capacity for one or two travel days between full hookups it may make more sense to just add the second Battleborn.

If you have a good quality shunt-based battery monitor you should be able to get some accurate figures related to the power needs for the residential fridge, lights, water pump, etc. during an average travel day. You should also be able to see what the actual charge rate is from the basic 7-pin connection as well. If the current set up is a little tight on AH for comfort you would then need to decide if the extra battery adds sufficient AH to get you comfortably between hookups or if more robust charging capability while traveling would be better.

We're planning to spend more time off-grid as well as further into the "shoulder-season". In the PNW that means less effectiveness from solar so that is partly a driver for the higher capacity charge from the TV. Plus I'm just not ready to start drilling holes in my new trailer roof for fixed panels.

[01tundra]

I'm currently looking into adding a Victron 12/12-18 DC-DC charger.

Since we always drive with the lights on to power the camera I was thinking about using the trailer's running light circuit as a trigger instead on adding wiring from the truck's ignition switch.

Our truck has a 30A trailer power circuit with 10 AWG back to the 7-way plug. I was struggling with the voltage drop through the factory 8AWG trailer charging wire all the way back to our battery in the back of the trailer, but remembered that I have a dedicated 1/0 cable pulled from the solar controller in the front pass thru directly back to the battery with a 25A breaker. Since I wouldn't be using our portable solar panel while being connected to the truck, the 1/0 could be used for both.

I've decided since we typically camp in the woods, increasing from our current 100W solar suitcase wouldn't be the best choice. So I'm toggling between adding a DC-DC charge vs a second BattleBorn battery.

Since our average power use in a 24 hr period of dry camping is around 10AH, it's hard to justify another $950 battery.....

What I haven't been able to nail down is if an "isolated" charger can still utilize chassis ground like the "non-isolate" or does it have to have dedicated ground wires ran?