BIM wiring and replacement for Lithium upgrade

[zambonidriver]

I have a 2023 Thor Resonate 32B, and i'm looking to upgrade my batteries to Lithium. I have an autodetect WFCO so i'm good there. I'm trying to figure out the wiring for the BIM that is in my rig and it's not what i was expecting to see. I know i need a lithium compatible BIM and was hoping this would be a direct wiring replacement and move to the LI-BIM 225 that is very common.


I've attached a photo of my BIM. The wires going to the batteries are obvious. I'm just trying to confirm the yellow and white wires in the pic. In looking at the precision circuits wiring diagram, i think the yellow wire is the ignition wire, the white wire is the ground, and the small red wire is the signal wire. Can anyone confirm? Thanks!

[16ACE27]

That's not a BIM, that's an isolation solenoid controlled by a IRD (Isolation Relay with Delay) or BIRD, (Bi-directional Isolation Relay with Delay)

BIM below:

[zambonidriver]

That explains it! Now i just have to find it. I expected it to be near the batteries but didn't see it behind the batteries in that compartment. I have a 50 and a 100 amp breaker in there and the BIRD, but don't see the BIM. Is it in a different spot in some RV's?

[16ACE27]

Originally Posted by zambonidriver

That explains it! Now i just have to find it. I expected it to be near the batteries but didn't see it behind the batteries in that compartment. I have a 50 and a 100 amp breaker in there and the BIRD, but don't see the BIM. Is it in a different spot in some RV's?

If you have a BIRD and isolation relay you don't have a BIM. Two different ways to accomplish the same thing.

[zambonidriver]

Do I need to add a BIM to install lithium or can I just wire to the BIRD?

[16ACE27]

Originally Posted by zambonidriver

Do I need to add a BIM to install lithium or can I just wire to the BIRD?

BIRDs are not configured for lithium batteries. They will work but will not protect the alternator from overheating due to excess charging current. The purpose of the Li-BIM is to protect the alternator and needs to be installed in place of the BIRD/Relay combo.

[zambonidriver]

Got the schematics from Thor today and now i see what i have. I have a sealed Trombetta and an Intellitec BIRD. In the attached i can clearly see the ground and the ignition wire, along with what i think is the emergency start wire labeled "ISOL RLY COIL" on the upper left corner of the BIRD. I just need to confirm that is the wire that gets sent to the "Signal" terminal of the BIM i'm installing. Can anyone confirm? Thanks for all of your help!

[Chateau_Nomad]

Apologies for bluntness, but there's tons of info and detailed instructions in extensive YouTube videos among other sources. If you're going to take on this challenge yourself, you should do the research.

Miswiring can damage expensive lithium batteries, so at least Google how to wire a Li-BIM 225. There are many wiring diagrams on the Internet showing different applications. Make certain you are comparing apples to apples and using the wiring diagram applicable to your coach.

[macdaddy1111]

Originally Posted by zambonidriver

Got the schematics from Thor today and now i see what i have. I have a sealed Trombetta and an Intellitec BIRD. In the attached i can clearly see the ground and the ignition wire, along with what i think is the emergency start wire labeled "ISOL RLY COIL" on the upper left corner of the BIRD. I just need to confirm that is the wire that gets sent to the "Signal" terminal of the BIM i'm installing. Can anyone confirm? Thanks for all of your help!

Bird has all the wires you need for bim 225. Label tjem there wires! Ha

I got a box of 160s! One day going crack open 160 and 225 and see what they changed.

[Korey & Tana Jackson]

Precision Circuits Tech Support staff are familiar with the process for converting from an Intellitec B.I.R.D. with Trombetta solenoid to a Precision Circuits LiBIM225.

We’ve been using a LiBIM225 for two years and over 20,000 miles on our 2018 Vegas 24.1. However, we replaced a regular PC BIM160. So far, the LiBIM works well and as advertised,