Designing Victron System for Keystone RV Travel Trailer

[EBKRV]

99% of trailers with electric brakes only have a mini sla battery that just charges off the 7 pin including those with a power tongue jack. Not travel trailers but just everyday flat or enclosed trailers. If your chassis battery isn't lasting more than a couple weeks you have something else connected to it draining the load. It's not an issue with FLA it's an issue with whatever is pulling a load when off

No loads with a battery disconnect right off the battery on all of the past 7 rigs I've owned over the years. The typical 12v FLA are junk IMO. Well not my opinion really when they have proven to be so with multiple rigs and multiple brands of them.

 

[justinm001]

No loads with a battery disconnect right off the battery on all of the past 7 rigs I've owned over the years. The typical 12v FLA are junk IMO. Well not my opinion really when they have proven to be so with multiple rigs and multiple brands of them.

You do realize that basically every car runs off a FLA battery and can easily go months even years without being used and still pull hundreds of amps instantly to start the car.

There's gotta be something wrong with your disconnect. You shouldn't be getting more than a 3% drain per month for FLA... it's basic science. Otherwise they couldn't sell FLA on a shelf and many of which sit for months.

 

[EBKRV]

You do realize that basically every car runs off a FLA battery and can easily go months even years without being used and still pull hundreds of amps instantly to start the car.

There's gotta be something wrong with your disconnect. You shouldn't be getting more than a 3% drain per month for FLA... it's basic science. Otherwise they couldn't sell FLA on a shelf and many of which sit for months.

Hmm any vehicle I've had sit for months have had issues starting...I know so as I have 3 vehicles that sit for 2-3 months at a time while we travel the US some need jumped after that time away...rigs FLA wired like this....battery pos post direclty to blue sea disconnect to 12V system in the rig...very simple shut off...this way it shuts the entire system down unlike most that are installed in rigs today that still have those parasitic draws. But I'm way past that have been using lifepo4 for a few years now without issue. Not trying to be a jerk but this is my real world experience with FLA's....this was the junk the interstate store by my sticks n bricks would sell me...they were the worst ever https://www.interstatebatteries.com/products/24m-efb?productline=marine

 

[SendIt]

What about power tongue jack? Running off the old FLA 12v? The 7 pin charging that battery only does it last sitting for 2 weeks...most don't none ever have had. I would have went straight from the dc-dc 24 to 12 converter to the factory wiring on the tongue and dumped the FLA myself.

If I were going to add a power Jack I’d tie into the house battery off of the main fuse panel. old speaker wire is pretty cheap to run up to the front and then I’d never have to worry about the Jack being dead.

 

[justinm001]

If I were going to add a power Jack I’d tie into the house battery off of the main fuse panel. old speaker wire is pretty cheap to run up to the front and then I’d never have to worry about the Jack being dead.

It would be easier to just swap the 12v on the 7 pin so it's always on instead of only with ignition.

Or just get a 50w solar panel aio and put it on the trailer roof then never worry.

Although I just hooked my trailer up after 6 weeks sitting and no issues using the Jack. Battery seemed fully charged

 

[SendIt]

Update for anyone reading this in the future:

We ended up adding three 550 watt panels and living in the trailer full time with no issues. Haven't had to run the generator after adding the panels. Here's the other thread about the solar design: https://diysolarforum.com/threads/sizing-solar-cells-for-couple-full-time-boondocking.54957/

And the final schematic: