Ready to install Lithium and Solar - What Am I Missing?

crosstrnr

I have a T@B 320s Boondock Edge with the original Interstate 100ah lead acid battery. This is the model with the 3-way Norcold refrigerator. I've made some purchases (all returnable) in preparation for lithium and solar.

Here is what I have ready to install:

• Ecoflow 100ah LiPo4 Battery
• Renogy Rover Li 40 Amp MPPT Solar Charge Controller
• 40A Circuit Breaker
  
• Ecoflow Delta 2 (as a secondary, portable battery -- includes built-in solar controller)
• EcoFlow 220W Bifacial Portable Solar Panel
• Battery Switch (Off-Battery 1-Battery 2-Batteries 1 and 2)

I'd like to eventually add a flexible solar panel to the T@B so that it can charge while driving (or when I'm too lazy to set up the portable panels!). If it could charge from both the alternator and the flexible panel at the same time that would be a bonus.

My T@B is not wired for solar, so I'll need to add the ports and connectors.

My plan is to:

1. Install the new battery in the front tub
2. Install the solar controller with a 40A circuit breaker in between the controller and the battery
3. Add a solar input port to the tub and wire that to the controller

I'm confused if I need a DC-DC charger and how to handle two inputs (alternator and panels) for the future.

Also, what else am I missing?
 

Grumpy_G

A DC-DC charger is not strictly needed. It is typically used to address the higher charging voltage requirements of LiFePo (14.4V for the Ecoflow battery). 14.4V is at the upper end of what a vehicle may run at, with many modern vehicles using "smart" charging strategies being much lower. However a DC-DC charger increases current draw from the tow vehicle which causes other challenges, either the voltage drop in the feed line is large enough to make the charger never reach the target voltage or the fuse for the trailer supply blows. 

You can have multiple power sources towards the battery even at the same time. That is a common scenario when a trailer with solar on the roof is being towed, power from the tow vehicle and the solar panel(s) at the same time. 

pthomas745

You need to sort out the cabling for the Ecoflow panels into whatever solar port you intend to use.  Some of the "batteries in a box" have "barrel connector" cables coming off the solar panel, and you would have to sort out the proper cable that will allow you to both: charge your trailer, and charge your Ecoflow. Your panels may have standard "MC4" cables coming from the solar panel, which will make your cable choices easier. 

There are many cables that will do this sort of thing for you.