942 AH of Lithium Batteries and Victron 12-12/50A DC to DC Charger
Just finished upgrading to lithium batteries in my 2007 Winnebago Journey 34H. After a lot of measuring and finger crossing, I found 3 of the new 314AH mini batteries from Dumfume will fit in my tray that was designed for 3x group 31 deep cycle batteries. There is no extra room and I had to create a new battery hold down. Needed new 3/0 battery cables too. The lithium batteries have both terminals on the small side. Everything fits and works with zero rubbing on the negative cables. Added a new Progressive Dynamics 9360 configured for lithium. Drop in replacement for my PD9260, simple swap in even the screw holes aligned and were reused. The existing electrical cables were all 4ga and the correct size for a 60A charger so no change was needed. Same with the 110 AC fuse and plug. Simple to keep things the same.
To protect the alternator on the RV I added a DC-DC charger. The Victron was just what the batteries needed. In the front electrical compartment of the RV was the aux start solenoid. The solenoid is designed to provide power to the house batteries when the engine is running. The 20 year old alternator is not designed to work with lithium batteries and would have killed itself trying to charge them. The solenoid has 2 control signals, one from the MOM switch and another to close the solenoid when the engine is running. I disconnected both of them. The white and yellow wires with electrical tape on them for now. There should be no way that solenoid connects the circuit between alternator and house now. From the alternator side I routed some 4ga to a 60A fuse and to the IN side of the Victron. Then connected the house battery side via a 60A fuse to the OUT and ran a 32' 4ga ground all the way back to the batteries. The direct line to the batteries seem to be a good idea due to issues with chassis ground reported. The positive connection to the solenoid is 3/0 gauge back to the battery.
Installed the Victron app on my phone and configured the Orion to be a battery charger for lithium batteries. Set the charge rate to 40A as I doubt I will need more than that while traveling. I added a second inverter and auto transfer switch to allow the AC/Propane fridge to run off the DC when we travel.
Now I knew that the Orion would get hot and did not want to put it into the front electrical box. I looked at my options and decided that mounting it outside the box was the answer. I purchased a 9x18 sheet of 1/8" rolled steel and did not want it to rust. All I had was pink Rust-Oleum paint. Actually, it is my wife's for some project and it just kind of ended up in my garage. Free paint for me.
Initial tests look good. I had charged all the lithium batteries before installing into the coach. Leave on a 2 month trip across North America in 2 weeks and am glad to have the extra DC power for various stops without hookups.