Installing a Lithium Battery Isolation Manager on an Older Coach

[TDServices]

Anybody ever install one of these (pictures )on an older coach like my 2003 Winnie 34hd does it just replace this solenoid ?

 

[deffinba]

The only problem is wiring it so the boost will me work. It needs a wiring change to apply 12V with the operation of the boost.switch.

 

[MikeyC-WO]

Get a ionic starter lifepo4 battery and a dc to dc charger and put the dc to dc between current bim and lithium keep all current functionality

 

[EverettO]

Anybody ever install one of these (pictures )on an older coach like my 2003 Winnie 34hd does it just replace this solenoid ?

Depending on how much juice your batteries can pull, you may not need this. I have two 100AH batteries, and this is not required for them. But if you have 4 (maybe even 3) it may be useful. I bought that BIM and then realized a)it was going to be a pain to install and b) I really didn't need it.

 

[Morich]

I have not done this , so lack personal experience to feel qualified to answer the questions!
But with no others throwing in, perhaps something less than best will at least start the discussion?
I'm sure there are others with more experience as we do see it discussed here. But when in doubt and not getting what I feel is good info, I am now going to AI more and more to check if the info there seems correct or at least a start in forming better questions.
Like many questiosn, I don't often take the first answer as totally correct but it can lead me to other places to confirm/reject the answers!
When I ask Copilot to explain the item pictured, this is just the first few paragraphs of the info it returned:

With no better info, perhaps run a few questions through and see what it may tell you. I got way tooo much return to snip and post in any practical way.
For my part, I do know several post involve using this item but that is not a deep base of knowledge to share!
Looks like a reasonable item to do the job and appears to be simple enough to install.
But that is not based on having done it!!
Some info further down the page seems hopefull?

 

[TDServices]

I did figure out where it goes wiring it up with the boost switch also can be done but you can’t use it to start the motorhome you can hold the switch and it will take a charge from the lifepo4 batteries to your chassis batteries but you can’t try to start the engine cause it will damage the lithium batteries I’m just trying to figure out which wire is ignition and which is signal lol those diagrams are crazy loaded

 

[wahoonc]

I did figure out where it goes wiring it up with the boost switch also can be done but you can’t use it to start the motorhome you can hold the switch and it will take a charge from the lifepo4 batteries to your chassis batteries but you can’t try to start the engine cause it will damage the lithium batteries I’m just trying to figure out which wire is ignition and which is signal lol those diagrams are crazy loaded

My understanding is it won't necessarily damage the lithium batteries the BMS will kick them out of the circuit if you try to pull to much current. My Lithiums are rated to 200 amps per BMS. I have heard you can use them to charge up the chassis batteries then let the button go and start the engine. I am in the middle of my conversion, but don't have it completed yet.

Aaron

 

[Morich]

It's super easy to get bad info, so check most anything we read?
I think th ehazard from holding the switch to use the lithium added to the lead start battery is not totally correct. I feel time is a major factor being overlooked.
When we speak of using the boost switch to charge the start battery, we may be overlooking how long it actually takes to put a real charge in a lead battery. If one is down too far, we know it takes 6-8 hours to get it back up to full charge. Not likely you will want to wait and hold the switch for that long if you are prepared to leave!
What folks may be confusing is the "surface charge" we see right after we take a charger off a lead acid battery. If we put a charger on for 30 minutes and take it off to test the voltage, we often see a really high voltage, even up into the 13 volt range from a very short charge!
But that is not a battery that is charged all down through all the cells and all the chemical! It will go back to dead when it all becomes stable again.
My thoughts on damge to lithium is not likely when we look deeper.
If we think of the lead acid battery being able to put out enough power to crank the engine and look at what the lead acid gives us, we can compare it to the lithium. Lead acid is slow, both charging as well as letting us use that stored power. Lithium is fast on both points.
Since lead is what we have used to start the RV most of the time, I see no way the starter that works with slow lead is going to overwork a much faster operating lithium in the short time we crank to get the RV started!
Is there any mention of a hazard to lithium in the install instructions with the new BIM item? I would think that would be a part of their directions if there is an actual question about ruining a set of new batteries!
It's not one I have read about here and I feel lithium and LI-BIM have a fair amount of safety built in by design! Maybe a call to the folks who build the new item would clear the question?

 

[TDServices]

It's super easy to get bad info, so check most anything we read?
I think th ehazard from holding the switch to use the lithium added to the lead start battery is not totally correct. I feel time is a major factor being overlooked.
When we speak of using the boost switch to charge the start battery, we may be overlooking how long it actually takes to put a real charge in a lead battery. If one is down too far, we know it takes 6-8 hours to get it back up to full charge. Not likely you will want to wait and hold the switch for that long if you are prepared to leave!
What folks may be confusing is the "surface charge" we see right after we take a charger off a lead acid battery. If we put a charger on for 30 minutes and take it off to test the voltage, we often see a really high voltage, even up into the 13 volt range from a very short charge!
But that is not a battery that is charged all down through all the cells and all the chemical! It will go back to dead when it all becomes stable again.
My thoughts on damge to lithium is not likely when we look deeper.
If we think of the lead acid battery being able to put out enough power to crank the engine and look at what the lead acid gives us, we can compare it to the lithium. Lead acid is slow, both charging as well as letting us use that stored power. Lithium is fast on both points.
Since lead is what we have used to start the RV most of the time, I see no way the starter that works with slow lead is going to overwork a much faster operating lithium in the short time we crank to get the RV started!
Is there any mention of a hazard to lithium in the install instructions with the new BIM item? I would think that would be a part of their directions if there is an actual question about ruining a set of new batteries!
It's not one I have read about here and I feel lithium and LI-BIM have a fair amount of safety built in by design! Maybe a call to the folks who build the new item would clear the question?

From my understanding of the battery chemistry it takes a whole lot of amperage to start a diesel motor I think that the lithium batteries will shut off during the switch time because they aren’t built to pump out that much amperage in 3 to 4 seconds , I think most are rated at 200 amps for 2 seconds that would be 400 but lead acid most diesel take 1200 ccs to start here’s a good post to read I just took it from a post

 

[TDServices]

My understanding is it won't necessarily damage the lithium batteries the BMS will kick them out of the circuit if you try to pull to much current. My Lithiums are rated to 200 amps per BMS. I have heard you can use them to charge up the chassis batteries then let the button go and start the engine. I am in the middle of my conversion, but don't have it completed yet.

Aaron

I did actually install my 2 lithium batteries in the coach and took a jumper cable from the positive side ( all negatives are grounded same
Spot. ) and turned on Renogy shunt app to watch what happened when I connect them straight across the chassis batteries started to draw almost 300 amps mind you they went from 12.07 to 13.05 in a few seconds and that’s when I decided I didn’t want to play anymore lol

 

[Morich]

Sorry, too much confusion on terms used!
I would suggest checking with the folks who build it as what we are getting here is missing way too many points to trust!

 

[Morich]

The reason for me to back away from part of that info is the way CCA (cold cranking amps) is used. It is a spec found in design and testing that gives us a "standard" to compare various batteries. It is not meant to say much about what any battery will do in real life but give a way to compare one battery size against another under very closely monitored conditions that we hope to never me in most fo our camping. I've forgotten much of the specs on CCA testing but it involves what we expect for how long at specific temperatures, not what amount of power we can get when we try to start the engine. Higher CCA is often good, if we are willing to pay for it, but I don't find it really much help on saying how much is actually used at any time over the life of my car.
Getting an engine to start has so many variables involved that the CCA is not a big help to me beyond buying bigger!

I think there is confusion about battery recommendations for different engines or vehicles as we will rarely see the test conditons in real life and all they are really trying to do is give a practical spec to use for shopping. If we wanted to crank one specific engine for 30 seconds at zero and still have 7+ volts left, the CCA would be good to know but that is a lab spec and not one I find too much value most of the time. It does nothing to tell me how much power I really need to start MY engine at any given time.
On the lead acid going from 12.07 to 13.05 is just the surface charge, not the true state of things way down in the battery where we can't test. What you were seeing was the "pile" of electrons that were stacked up at the post. To get the true charge we have to give that pile time to spread out and get stable after we have charged it some.
Sometimes called surface charge, it is talked about as being like pouring something thick like syrup into a hole in a barrel. If we look too soon after we have been charging, we may see a pile of syrup at that hole and since we can't see the rest of the battery/barrel, we may assume it full. But if we wait several hours for that charge to spread out in the rest of the battery, we may find it is still pretty empty!
Lead acid are very slow, so when we think we got one charged in less than a hour ( or four!) it is just that we are seeing the pile of electrons that have not spread out yet!

 

[TDServices]

Dakota lithium makes lithium cranking batteries though

 

[TDServices]

The reason for me to back away from part of that info is the way CCA (cold cranking amps) is used. It is a spec found in design and testing that gives us a "standard" to compare various batteries. It is not meant to say much about what any battery will do in real life but give a way to compare one battery size against another under very closely monitored conditions that we hope to never me in most fo our camping. I've forgotten much of the specs on CCA testing but it involves what we expect for how long at specific temperatures, not what amount of power we can get when we try to start the engine. Higher CCA is often good, if we are willing to pay for it, but I don't find it really much help on saying how much is actually used at any time over the life of my car.
Getting an engine to start has so many variables involved that the CCA is not a big help to me beyond buying bigger!
View attachment 2465371
I think there is confusion about battery recommendations for different engines or vehicles as we will rarely see the test conditons in real life and all they are really trying to do is give a practical spec to use for shopping. If we wanted to crank one specific engine for 30 seconds at zero and still have 7+ volts left, the CCA would be good to know but that is a lab spec and not one I find too much value most of the time. It does nothing to tell me how much power I really need to start MY engine at any given time.
On the lead acid going from 12.07 to 13.05 is just the surface charge, not the true state of things way down in the battery where we can't test. What you were seeing was the "pile" of electrons that were stacked up at the post. To get the true charge we have to give that pile time to spread out and get stable after we have charged it some.
Sometimes called surface charge, it is talked about as being like pouring something thick like syrup into a hole in a barrel. If we look too soon after we have been charging, we may see a pile of syrup at that hole and since we can't see the rest of the battery/barrel, we may assume it full. But if we wait several hours for that charge to spread out in the rest of the battery, we may find it is still pretty empty!
Lead acid are very slow, so when we think we got one charged in less than a hour ( or four!) it is just that we are seeing the pile of electrons that have not spread out yet!

Does anyone know the wiring on these coaches I can find everything but I get confused on what has to go where on the little wires I got where the coach batter and chassis battery hook up but then there’s the ignition wire ground wire ( obvious ) and the signal wire I have been looking at the schematics my head hurts any help would be appreciated I attached photos

 

[TDServices]

The reason for me to back away from part of that info is the way CCA (cold cranking amps) is used. It is a spec found in design and testing that gives us a "standard" to compare various batteries. It is not meant to say much about what any battery will do in real life but give a way to compare one battery size against another under very closely monitored conditions that we hope to never me in most fo our camping. I've forgotten much of the specs on CCA testing but it involves what we expect for how long at specific temperatures, not what amount of power we can get when we try to start the engine. Higher CCA is often good, if we are willing to pay for it, but I don't find it really much help on saying how much is actually used at any time over the life of my car.
Getting an engine to start has so many variables involved that the CCA is not a big help to me beyond buying bigger!
View attachment 2465371
I think there is confusion about battery recommendations for different engines or vehicles as we will rarely see the test conditons in real life and all they are really trying to do is give a practical spec to use for shopping. If we wanted to crank one specific engine for 30 seconds at zero and still have 7+ volts left, the CCA would be good to know but that is a lab spec and not one I find too much value most of the time. It does nothing to tell me how much power I really need to start MY engine at any given time.
On the lead acid going from 12.07 to 13.05 is just the surface charge, not the true state of things way down in the battery where we can't test. What you were seeing was the "pile" of electrons that were stacked up at the post. To get the true charge we have to give that pile time to spread out and get stable after we have charged it some.
Sometimes called surface charge, it is talked about as being like pouring something thick like syrup into a hole in a barrel. If we look too soon after we have been charging, we may see a pile of syrup at that hole and since we can't see the rest of the battery/barrel, we may assume it full. But if we wait several hours for that charge to spread out in the rest of the battery, we may find it is still pretty empty!
Lead acid are very slow, so when we think we got one charged in less than a hour ( or four!) it is just that we are seeing the pile of electrons that have not spread out yet!

Got it all hooked up , just had to run a wire to ignition on terminal and so far so good it will equalize charging between batteries even with nothing on until the lithium batteries drop to 13.4 ( in the instructions ) photo included

 

[Morich]

Sorry, my wiring link has gone

down and been down for some time now, so I was never able to get to them again.
They seem to be making changes and wemay be cut off from info in the future!

 

[TDServices]

Sorry, my wiring link has goneView attachment 2469723 down and been down for some time now, so I was never able to get to them again.
They seem to be making changes and wemay be cut off from info in the future!

Seems everybody is doing that unless you pay for it anymore lol

 

[Morich]

Yes, I see that coming quicker and quicker. I suspect my interest here is about to go with that change as I no longer have an RV for my own use and am moving away from the idea of replacing the last one as it is getting more and more expensive to drive and less and less that we are interested in seeing!
But as another point, when I look at the drawings of the fully solid state lighting, etc. on newer RV, it quickly puts most of us out of DIY when we can't justify the test equipment needed to do the job.
No need to shoe horses if we run on gasoline!