LiFePO4 coach battery conversion for an Itasca Meridian 34Y

[mpl239]

Anybody having done a Li conversion for coach batteries for a Meridian 34Y, I would appreciate some guidance. I have a 40 ft sail boat with 600 ah CALB prismatic cells, charged by solar, shore, and alternator charging. I changed the alternator to a 125 amp Hamelton Farris marine alternator with a Balmar 614 external regulator and a Xantrex 2000 watt Freedom SW inverter/charger. Using a Blue Seas ACR to separate the AGM start from the Li house batteries. All systems are connected to buss bars. Each system has a different voltage set for charging, with the solar being lowest and shore the highest. This allows all, except the alternator to turn off when they reach target voltage. I have a group 24 lead acid in parallel to the Li, as a surge protector, to protect the alternator, if not shut down by turning off the field off first to minimize the alternator shut down spike as the field collapses slowly with a normal engine shut down.

On the 34Y I do not want to change the alternator, I intend to use a 30 amp DC-DC charger or a Battle Born Li 225 BIM to limit the charging current. The 34Y has shore on board charger stock Cummins alternator and solar. Looking at the wiring diagrams and speaking with Winnebago folks, I am somewhat confused on how to wire this. It is my intent to charge to 13.5 V (I am ok with a 70% - 80% charge on Li. to simplify my install). With the stock installation, it looks like charging sources feeds the coach solenoid which feeds the existing BIM which feeds the coach batteries with a pass through for chassis batteries. I am thinking that if I put the DC-DC after the coach solenoid and before the BIM I should be ok. Since this is the girlfriends RV and not my boat, causing things to melt and smoke would not be good for my life or relationship.

Has anybody gone down this path or something similar willing to share information and pointers.


Michael

 

[bpcannan]

I have a 2010 Winnebago Journey Express 34y (near equivalent to the Itasca Meridian 34Y) and converted to LiFePO4 in 2022.

Parts used were
o 3 X 100AH 12V Battleborn LiFePO4 Batteries
o 3000W 12V, 50AMP 2 X 120V Victron Multiplus Inverter/Converter
o 225AMP Lithium Battery Isolation Manager, Battery Guard Autoselect
o Victron Digital Mulicontrol Panel, Victron BMV-712 Battery Monitor
o 14-2 NMG and 6/3 NMG Wire used in installation
plus a shunt and fuse setup.

The shop putting it in for made a cover in the battery bay to close that opening and minimize dust dirt.

Our objective was to convert the whole coach to 50 AMP 120V service. To Avoid extensive cost and re-wiring the installer devised a workaround whereby a switch was installed in the shorepower bin (next to the battery bin) that meant when we plugged our 50AMP shorepower cable into that switch and flipped the NORMAL button to BYPASS on the Progressive Industries interior wall monitor we drew from he batteries and all outlets were HOT.

We did not have an objective to run the AC off the batteries nor any thing more than a minutes use of the Microwave - so this worked for us. Would need at least 300AH more for that.

We like it and added 3X200W Bouge RV CIGS solar panels this winter to help keep them charged in state parks without hookups.

Good luck.