Originally Posted by JohnnyFry
I have ordered a 150 AH battery ( 4 individual cells ) and a BMS from Ali Express but have not yet received them. Cost of the Battery was about $450 and the BMS was about $55. I also ordered a 20 amp DC/DC charger from Renogy. I have received the charger. I had originally considered BattleBorn, which is a great product BTW, after speaking with the CEO at the Escapade Rally last year but waited to do more research. I came on to Ali Express theough a YouTube series by Will Prowse who seems t have made himself into a one man testing laboratory for all things Lithium. I will post more on my project when the batteries and BMS arrive. I feel that 150AH is sufficient for the way I do business in my RoadTrek. One caution: you are pretty much on your own for support so an Engineering or Technical background is pretty important for success.
Johnny, when you install your Renogy DC-DC charger, you'll find their instructions say to install the positive and negative to your chassis battery. When installing my 40A version, I found I had no negative wire running back to the chassis battery since it is chassis grounded somewhere in the engine compartment. I called Renogy to ask if I could make a ground to the chassis in the rear compartment that houses my coach electrical system. They said I could, I did, and all works well.
One other tip. When you connect your ignition wire to the DC-DC charger (needed to activate the charger) consider installing a small lighted on/off switch on the ignition circuit. Allows you to control the engine charging.