Hi everybody! New user here but long time lurker for good information. I used this and many other discussions on this site to educate myself on the electrical system in my 2021 Grandby as well as on lithium battery installs and component upgrades.
I recently installed two dakota lithium 135 AH batteries into the factory location of my camper, battery compartment on the left just inside the rear door. They are slightly smaller than the factory batteries and fit in there very well. Using information I got from here I purchased a victron bluetooth dongle and installed it into my overland solar 100/15 mppt in place of the cable running to the circular screen mounted in the cabinet face. I was able to hook up using the Victron app on my phone, update the firmware of the mppt, and update the settings for lithium batteries. Dakota Lithium tech support was very helpful with me in ensuring all the settings were correct for their batteries.
I also removed the factory circular mppt screen/controller in the side of my cabinet and replaced it with a victron bmv 712 battery monitoring system. The two screens are exactly the same size. I installed the shunt that came with the bmv 712 in my existing battery compartment. By taking the doors off of the cabinets and drilling one small hole from the battery compartment up through the bottom of the compartment above it I was able to snake the data cable up through it and under the stove top, on top/behind the heater, and down to the monitor screen by following the path of factory wires, lines, etc. I have large hands so it was tight but very do able for the diy'er.
With the Victron App this worked amazingly, and was the simplest set up I could come up with for my existing setup and was done in half a day. Just got back from a 10 day baja trip and this worked great for us the whole time. I have the largest 130L fridge that is two way and our older AGM batteries were toast before, dieing with just minimal light useage. I have the 160 panel on the roof. I also have the overland solar bugout flexible panel for more options with forest/camp charging when parking is not ideal for maximizing solar charge.
I was crunched for time before the trip so I did not tackle the wiring upgrade or a DC/DC converter to maximize alternator charging but will likely do that at some point in the future. I found that i did not need it with my battery capacity and drive time for this trip. I do not have a smart alternator but dakota lithiums tech support told me that even if i did their batteries with the bms were fine this way.
The dakota lithium batteries were not cheap but they have an 11 year warranty, have an internal battery management system with temperature regulation, and the 135Ah batteries have the capabilities of automotive use so no issues with direct alternator charging.
All said the battery upgrades and system components cost around $3000 and more than exceeded my expectations and our electrical use.
I am no expert on any of this, in fact, I am extremely thankful for the experts in here that helped me understand the systems and components involved with our campers! Thank you all for your time and information! I felt compelled to write this in hopes that it will help someone in the future who was struggling with the process as I was. I am sure there are better/more efficient ways, but this works, so I wanted to pass it on, because it was relatively simple and easy.
Thanks again! Hope this helps someone, somewhere in the future!
Happy Camping,
D
