Will the alternator charge house batteries while driving?

[Fun Camp]

2004 Monaco knight. I recently had to purchase new house batteries for my 2004 Monaco night. I purchased a lithium 460ah battery and I am looking to make sure that the alternator won’t charge the house battery while driving and only charge the chassis batteries. I do know from my research that I’ve done that the alternator has an isolator relay delay switch, which supposedly is bi directional and will charge house and chassis batteries while driving. This is a problem as the alternator can’t support the draw from the lithium batteries. My question is, is there a way to disable/unplug this isolator relay delay switch to keep this from happening and only charge the chassis batteries? Also, is there a way to test the relay? Does anyone know the parameters in which it kicks on and kicks off? The manual doesn’t have any information about what the relay delay switch does or the parameters. I appreciate any all information anyone is able to provide. Thank you.

 

[Joe Hogan]

There are Battery Interrupters for this, Typically a BIRD ( Bi-Directional Isolator Relay Delay) or BIM (Battery Isolator Module) system.
With Lithium House batteries you want to either manually set the charging parameters or get one that is made for a Lithium house battery. Either style BIRD or BIM are readily available.

 

[BGMAC]

I changed over to lithium last year before I went on my Alaska trip. I read the same thing about the draw damaging the alternator. However that’s only if the lithium battery is drained quite a bit.
So my routine is if I’m on the battery a good bit “boondocking” I’ll crank up the generator for a while before taking off. Many use the generator going down the road for AC and other things and that should take care of the load you mentioned.

Anyway, that is my thinking and after being on the road 2 month straight and not sitting anyone place for more than 3 days I’ve had no problems.

The only odd thing I did was add a trickle charge to my chassis battery. Now when my 110 is alive it charges the battery.

 

[Neal]

The Li-BIM is designed to regulate the charging on a timer basis.

https://www.amazon.com/Battle-Born-Batteries-Lithium-Isolation/dp/B07DY8S815/?tag=rvf01-20

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[RollingManCave]

2004 Monaco knight. I recently had to purchase new house batteries for my 2004 Monaco night. I purchased a lithium 460ah battery and I am looking to make sure that the alternator won’t charge the house battery while driving and only charge the chassis batteries. I do know from my research that I’ve done that the alternator has an isolator relay delay switch, which supposedly is bi directional and will charge house and chassis batteries while driving. This is a problem as the alternator can’t support the draw from the lithium batteries. My question is, is there a way to disable/unplug this isolator relay delay switch to keep this from happening and only charge the chassis batteries? Also, is there a way to test the relay? Does anyone know the parameters in which it kicks on and kicks off? The manual doesn’t have any information about what the relay delay switch does or the parameters. I appreciate any all information anyone is able to provide. Thank you.

I am at a similar stage as you. I found a an Isolator next to the house battery and it looks like one side is hooked to House and the other Chassis. It also has another thin wire going somewhere in the matrix. I took a amp reading of the wire without the engine on: 0 amp. Engine on .75 amp. I am guessing this is what you described. I am thinking about cutting the wire and putting an on/off switch in the middle of it. Currently I can charge the lead acid with solar during the day and use a battery charger running off one of my Lithiums at night. I would like to just get my Refrigerator hooked to my lithium and keep the lead acid. I have a non-isolated system so I don't think that will work without pulling the refrigerator out to get to the negative/ground wire. I checked out the LI-225 Bim and they work great for most people but when they fail it cause folks a lot of problems. I watched a vid of a guy taking one apart and I was not impressed with the technology. It had a plastic plunger that pushed a cog on a gear that rotated the switch off and on. The guy seemed to think it was fine and he is probably right. I like my idea of a manual switch better so I can flip it on if i need it. Specs on my alternator show 225 amps, so if correct, I should be able to run it for at least a 1/2 hour at a time. A timer switch would be ideal. I purchased the the LI converter replacement on sale so eventually I will probably take the leap of faith. The pilot in me says Install the Li-225 BIM and the manual swithch. Hope some of my ramblings was of some help.

 

[Texas Clodhopper]

I just changed to LiFePo4 batteries, and I'm using the Li-Bim that @Neal mentioned. It cycles the alternator to charge for 15 minutes and off for 30. For less than $150 I'm possibly saving the expense of replacing the alternator.

 

[Neal]

I just changed to LiFePo4 batteries

Did I miss a post and pictures, story??? He says he's at a NKK rally and now he says he has LiFePO4's. I just don't know what to believe!

 

[Texas Clodhopper]

I still have so much paralysis by analysis that I'm brain-dead. All I remember is that I got rid of 8 wet cell batteries and the heavy tray they were in, and now with 4-230Amp LiFePo4 batteries, I have gained lots of storage space and lost a few hundred pounds of dead weight. I'm now thinking 1200 watts of solar would be nice. Damn money pit.