Pace Arrow: F-53 alternator, How to disconnect from house batteries?

[MrMudstud]

Gents, my house batteries are about gone and I want to change out to lithium batteries, since I have 540 watts solar to accommodate us. Besides changing out the converter, it is best to disconnect the alternator from charging the house batteries while driving. My alternator is a 130 amp Ford F-53 2002 year unit; so don’t want to possibly burn it up, and still want to charge the chassis battery. On Fleetwood make, there is a Battery Control Center to monitor the battery charging system from RV Custom Products. The recommended setup with lithium is to connect a DC to DC charger so not to overload the alternator.

Question:
How to I get around this or how and where do I disconnect the house battery charging from the alternator in the Battery Control Center? The chassis and house wire harness are all encase in the wire looms, and is impossible to trace where the wires go. Just point me in the right direction, what am I looking for and what is the best easiest way to accomplish my task. Thank You in advance for your time and assistance from your talented skills and knowledge.

[vsheetz]

I'd check the actual current your lithium batteries are pulling at low SoC to assess the need.

If then a need, consider to install a DC2DC charger.

My 600ah lithium bank pulls 40-45 amps at low SoC. I've made no modification to my house battery alternator charging setup.

[twinboat]

If there are 3 solenoids in the BCC, its the one that don't look like the other two.

Push the boost start switch, on and off, and listen for it clunking, that's it. Simply remove a small wire and your done.

Save some money and buy a BIM for Lithium. It takes the place of your isolation solenoid and has alternator saving logic controls.

You can mount it nearby and run 2 short battery cables from your disabled isolation solenoid.
Doing it that way makes it easy to return to normal when you upgrade the RV and take the Lithium batteries back out.

[MrMudstud]

Originally Posted by vsheetz

I'd check the actual current your lithium batteries are pulling at low SoC to assess the need.

If then a need, consider to install a DC2DC charger.

My 600ah lithium bank pulls 40-45 amps at low SoC. I've made no modification to my house battery alternator charging setup.

Some good points to keep in mind, thanks for the tip.......

[MrMudstud]

Originally Posted by twinboat

Push the boost start switch, on and off, and listen for it clunking, that's it. Simply remove a small wire and your done.

Save some money and buy a BIM for Lithium. It takes the place of your isolation solenoid and has alternator saving logic controls.Attachment 287605

Thanks twinboat, that answered my question, which one and where. Good idea on the BIM for Lithium too.......

[computerguy]

I did a write up on this and included a schematic. It is in this forum somewhere probably 3 years ago or so.
Did it on a '16 Bounder but the BCC is basically the same.

[MrMudstud]

Originally Posted by computerguy

I did a write up on this and included a schematic. It is in this forum somewhere probably 3 years ago or so.
Did it on a '16 Bounder but the BCC is basically the same.

Good read and learn some good ideas and information. Thanks computerguy.......

[nairbg]

Originally Posted by MrMudstud

Question:
How to I get around this or how and where do I disconnect the house battery charging from the alternator in the Battery Control Center? The chassis and house wire harness are all encase in the wire looms, and is impossible to trace where the wires go. Just point me in the right direction, what am I looking for and what is the best easiest way to accomplish my task. Thank You in advance for your time and assistance from your talented skills and knowledge.

If your BCC is the F73-1020 as mine is:
I asked this same question of John at RV Custom Products. He provided that pulling fuse F22 would defeat the function of the charge sharing, in both directions, so the solar charge controller will also not ever feed the chassis battery.
He also offered that pulling this fuse may or may not defeat the Aux start function as it is the same relay that connects the batteries for this function, but some Aud Start dashboard switches are wired directly, and not through F22.

[MrMudstud]

Originally Posted by nairbg

If your BCC is the F73-1020 as mine is:
I asked this same question of John at RV Custom Products. He provided that pulling fuse F22 would defeat the function of the charge sharing, in both directions, so the solar charge controller will also not ever feed the chassis battery.
He also offered that pulling this fuse may or may not defeat the Aux start function as it is the same relay that connects the batteries for this function, but some Aud Start dashboard switches are wired directly, and not through F22.

Thanks nairbg, this is some good info, and I will keep this in mind.......