Advice on Lithium and solar

[bcrvman]

Originally Posted by Old_Salty

We have a 2021 3791RD Legacy with the factory solar (not super solar) and FLA batteries. As our needs have changed, we plan on being off grid more and are looking to install 3 - 100 Ah lithium batteries to begin the upgrade process.

Our coach has an onboard generator we plan on using occasionally so we need the capacity to start the genny. 3791RD has the residential fridge.

The system has a Victron 100/30 MPPT. Stock converter and 2000 watt inverter. Stock shunt - how to connect genny leads?

Our concern is the ability to power the furnace and fridge through the night and the recharge time for the batteries. I am a newb in this and have found a lot of posts get quickly confusing as they tend to go deeper than I can comprehend at this point.

Thanks in advance.

I don't know how much the furnace uses and it is variable. The frideg I do know, I used a KillAWatt meter on it for many days and calculated the average. It is 1,500Wh per day or 125Ah from your batteries w/o taking losses into account. If you have Lithium, 2 of the 100AH will do, but if the furnace uses as much or more then I would get 4. I have 6 with 1,080 Watts of solar and a 150/70 MPPT. Good for a few days and much longer in the summer.

[cgeis48]

We purchased a 2022 Montana 3231CK in October. The factory had already installed the solar panel but the RV has been at the dealership since November for warranty repairs 90 miles away. So I’m wondering, does anybody know if a one panel solar system that’s factory installed, on a new Montana, come with an lead acid or other battery? How many? Thanks.

[AZ Traveler]

Carl,

Batteries are installed at the dealer. If you have a residential reefer you likely have 2 lead acid batteries but there is not a standard configuration.

[PNW Fireguy]

I am arguably the biggest proponent of DIY LiFePO4 battery packs on the MOC. That being said if someone comes to this site for help as a newbie I would not recommend for them to build their own battery pack. While the cell matching and assembly are simple task (maybe), the daily management and interpretation of the data the components are providing may be greek to many. There is a market for BB, LION Energy, Renogy, SOK, Chins, blah, blah, blah. I built a pack that is the equavalent kwhr capacity of 14 BB units, but to someone without the knowledge to care for it it worthless.