2021 Thor Magnitude SV34 Electrical Overview

[mitchk-SKO]

Hello! My buddy just bought a 2021 Thor Magnitude SV34. I am trying to help him get an understanding of the electrical but it turns out I need a hand with that as well.

This system has been upgraded to lithium. There are 2 x 280Ah SOK lithium batteries installed in parallel. They are fused out properly and complete 12v battery disconnect switch was installed as well.

His shore power wasn't working to charge the batteries yesterday but I am realizing from this forum that although the main battery disconnect switch was lit up that could be due to the fact that shore power was connected but not necessarily because the battery disconnect switch was turned on. He has a WFCO WF-9855, which I see does not have a lithium option so we might need to upgrade it. The converter unit also converts the generator power to 12v correct? It looks like the WF-9855 is just plugged into the back of the WFCO breaker unit so as long as the shore power and generator are connected to their own breakers (and they are on) then the WF-9855 would be getting power and charging the batteries correct?

The solar is slowly charging the batteries but he wasn't able to find the location of the alternator charger. Where is that located? I'm assuming that would also need to be upgraded for the lithium batteries?

 

[16ACE27]

although the main battery disconnect switch was lit up that could be due to the fact that shore power was connected but not necessarily because the battery disconnect switch was turned on.

Correct - a common misunderstanding.

 

[PS89]

but he wasn't able to find the location of the alternator charger.

Well, the alternator is on the engine... Factory schematic shows a BIM arrangement to handle the charging of the house battery from the alternator, it's probably mounted in the battery compartment area. Since a PO upgraded to Li, it's quite possible they changed the original setup, perhaps by adding a DC2DC charger or
by installing a Li-BIM225.

so as long as the shore power and generator are connected to their own breakers (and they are on) then the WF-9855 would be getting power and charging the batteries correct?

Charging from either shore power or the generator (via the converter) requires both that the 50A circuit breaker (probably in battery compartment) not be tripped and also that the BATTERY DISCONNECT relay be in the closed position. If either are open, no charging from the converter will take place.

Have him register his VIN at Thor's Owner's site and download the schematic package. See page 17.

A note for units with both solar and a LiBIM225. Do not expect the LiBIM to cycle very much if the sun is shining and the solar system is producing power. The SCC will hold the Li battery bank voltage above the threshold of the LiBIM's trigger voltage so it won't activate when it might otherwise have.

 

[mitchk-SKO]

Well, the alternator is on the engine... Factory schematic shows a BIM arrangement to handle the charging of the house battery from the alternator, it's probably mounted in the battery compartment area. Since a PO upgraded to Li, it's quite possible they changed the original setup, perhaps by adding a DC2DC charger or
by installing a Li-BIM225.


Charging from either shore power or the generator (via the converter) requires both that the 50A circuit breaker (probably in battery compartment) not be tripped and also that the BATTERY DISCONNECT relay be in the closed position. If either are open, no charging from the converter will take place.

Have him register his VIN at Thor's Owner's site and download the schematic package. See page 17.

A note for units with both solar and a liBIM225. Do not expect the LiBim to cycle very much if the sun is shining and the solar system is producing power. The SCC will hold the Li battery bank voltage above the threshold of the LiBIM's trigger voltage so it won't activate when it might otherwise have.

Yes, excuse my poor language choices this rushed morning! I meant to say BIM instead of alternator charger. But I couldn’t think of the name in the moment!

His lithium batteries are under the dinette couch at the entrance of the side door. But it looks like stock they are under the entrance steps. I will check that location and try and find whatever BIM is currently installed. I’m assuming I’ll need to upgrade that to either a lithium BIM like you talked about or dc-dc charger. I’ve used a bunch of the victron Orion units before so maybe I’ll just upgrade to that.

Thanks for the vin advice! I’ll tell him to check that out!