Owner of "new" 310RL and getting schooled on the electrical system. Looking at upgrading the existing LA battery to 1 or 2 LFP ones. No inverter. I know to change the solar controller and converter setting. Question is about charging from tow vehicle. Read that TV won't keep LFP charged due to insufficient voltage. Concerned about keeping fridge (12 VDC) cold when travelling. On sunny days, no issue as 320W panel will keep the battery topped off. Question is on rainy/cloudy days. With an LA battery, the TV would keep in topped off but what to do with LFP? Do I need a DC-DC charger in line with the 7-pin 12 VDC wire from the TV to keep the LFP topped off? Am I worried for nothing?
Well, I would offer that it might not be 100% necessary, but would certainly contribute to “tummy comfort” while traveling.
Remember that the refrigerator, will only experience “Higher Draws” when the compressor kicks in. So, you will have peaks and valley’s in your amp draw on an intermittent basis while you travel. As you already know your converter and solar controller have settings that are used to change the charging profile when hooked to a LFP Battery. So adding a DC/DC would provide the opportunity to optimize your LFP charge rate from the truck on travel days(regardless of weather)
Your solar will contribute some amount of charging even on a cloudy day, so taking that into consideration, coupled with the truck voltage, you could in fact be worried about nothing.
Having said that, we have a DC/DC charger that came installed on our 2024 310 RL from the factory, I have never got confirmation as to why, but my take is it was included in the Bill of Materials as a result of the disk brake option we ordered.
The disc brakes use a 12v hydraulic actuator powered from the coach battery, so we experience more draw on our Flooded Lead Acid battery then the standard offering.
I think this could come down to a personal preference.
Personally, I am glad we have ours as it also acts as a battery isolator, when it isn’t activated by the trigger wire, so there is no risk of depleting the truck battery if the coach remains hooked up for an extended period of time for some reason .
If you choose to go this route, be conscious of your strategy for the trigger wire. Ours was hooked to one of the light circuits, so the lights needed to be on for it to activate. This was not mentioned in the owners manual and really wasn’t an issue for us as we tow with the lights on anyway, but for those that rely on the auto light setting of their vehicle, they could find themselves with a low coach battery.
At the end of the day, I would recommend it.
I would also offer we have towed 11 hours straight twice and have never had any issue with our 12 volt refrigerator or freezer not being able to maintain temperature.( we monitor with a wireless thermometer while traveling)
Decisions, Decisions, Decisions!
) The way I understand it, the battery gets its charge voltage from three sources: Solar controller, Converter, and the truck's 12VDC line. Does anyone know how these are actually wired to the battery? Are they and the 12VDC circuits all wired together on one 12VDC bus? If so, it really just comes down to what source is providing the highest voltage I think. In this case, the truck will almost never provide enough voltage to top off the LFP battery. It would be great to see a wiring diagram of the entire 12 VDC system.
