Disabling the alternator from charging my lithium house batteries

[3x5]

Disabling the alternator from charging my lithium house batteries

I am installing lithium house batteries. Before I have to drive away later this week, I will need to disable my alternator from charging them or the lithiums might burn out the alternator. I will have to wait to find a suitable charger. And I believe it will have to be disabled for a charger anyway.

In my pictures below, I found that the solenoid in the center is the boost solenoid, and the one on the left is the starting solenoid. When I turn the key to the on position, I get about 12 volts of positive on the top right post of the start solenoid. When I press the battery boost switch on the dash, I get about 12 volts of positive on the top left post on the boost solenoid. I am not getting anything from the top right post of the boost solenoid.

I would appreciate any help with this. What have you Alpiners that installed lithiums done about the alternator?


Thanks.

[andy29847]

I do not have lithium battery experience, but I am interested in what you are doing.

It sounds like you want to use you inverter/charger to charge the house batteries when you are on shore/generator power and use your alternator to charge the chassis batteries when you are on the road. It seems to me like you will have to fully separate the 2 battery banks from each other. I'm a little concerned because you need to ask about this. You may be working a project whose requirements exceed your training and experience.

You need to find your battery isolator and remove the house battery cable there.

My coach is different than yours. I'll share some photos and diagrams that I made for my coach on the chance your coach will have similar components. Good luck.

[twinboat]

Remove and tape up the wire I marked. That will disable chassis to house charging.
It also disables boost starting but you could add a switch to that wire and use as needed.

The large cables are the ones a DC to DC charger will connect to.
One is house battery and the other is chassis battery.
You don't actually stop the alternator charging from anything, you stop the chassis battery from charging the house battery.

[twinboat]

I see you have a echo charger in there.

That's for the house battery to charge the chassis battery while on shore power.

May need to disconnect that, it's probably not lithium compatable.

[theoldwizard]

IMHO, the best solution is to completely eliminate charging the house batteries from the alternator. Instead, buy a good DC-DC charger.

If you are concerned about a dead vehicle battery, buy one of those jump start packs.

[El Chapo]

LiBim will limit your alternator from overcharging. I swapped to one when i installed my lithiums.

[paul65k]

Originally Posted by El Chapo

LiBim will limit your alternator from overcharging. I swapped to one when i installed my lithiums.Attachment 391703Attachment 391704

We have already had this conversation the DC-DC charging solution is much better

[3x5]

Andy:
I agree that I may be working a project whose requirements exceed my training and experience. I was lead to believe that Battleborn tech support could give me enough guidance, so that I wouldn't be asking these kinds of questions. Now I am trying to get some education on this. For now I am going to bail out by disabling the alternator charging so I can get moving again, and I will figure out which charger later.

I don't have a separate battery isolator in my 2005 Alpine. I believe it is incorporated into the solenoid. I could remove the house cable from that, and I bet that would disable. Thanks.

Twinboat:
Thanks. I got it. That appears to be the signal wire. So in addition to being activated by the manual boost switch, something else must be using it to tell the solenoid to connect the batteries to charge. "You don't actually stop the alternator charging from anything, you stop the chassis battery from charging the house battery." That make good sense. This is the simplist way. I just wasn't confident that there wasn't anything more to it. And I will also remove the echo-charger.

El Chappo:
How is the Li-BIM working for you? Battleborn pushed me hard to get one over the DC to DC charger. But most others like theoldwizard and Paul think the DC to Dc charger is safer. I am surprised that the two wires on the bottom to the house and chassis batteries are so small.

[Cinequip]

In a Vansco equipped coach, the Boost solenoid is also used to connect the House and Chassis batteries together, to keep the House charged off the Chassis when driving, AND to keep the Chassis charged off the House when plugged into shorepower (or generator running). If you disconnect the left top wire, as Twinboat described, you effectively disconnect the two battery banks from each other, and the alternator cannot charge the house. This will allow you to drive down the road, without worry of damaging the alternator. IF YOU HAVE AN ECHO CHARGER, you'll also need to disconnect the battery cable that goes to the chassis batteries from that. Later model coaches don't have an echo charger, the Vansco took over that task. I'm not sure what year they eliminated the Echo Charger.

Now, as to the BIM vs. DC-DC charger question, I have neither. However, I installed solar on the roof at the same time as lithium batteries. My house batteries are maintained (charged) from solar, or when plugged into shore power through the inverter/charger. I saw no need to also have the alternator charging the house, as I drive only during the day when the solar panels keep the house charged very nicely. I have enough lithium battery capacity to easily power our coach overnight, until the next solar day.

I agree with Paul over the preference of DC-DC charger instead of the BIM, if you were to use one. Once I learned how the BIM works, was the last time I'd consider using one.

If you don't install solar, I suggest installing a DC-DC charger.

One more thing. If you disconnect the solenoid (and echo charger), you'll need to figure a way to trickle-charge the chassis batteries when parked long term. You could purchase a inexpensive 2 amp battery charger/maintainer, or Paul and I have an elegant solution for that, if you get that far.

Cheers.

[El Chapo]

I've had the LiBim in there for about 10 months and 5000 miles. It works great and is the easiest to do. I have done a DC to DC in my Jeep and previous Class C, they aren't near as easy to install and you do lose the ability to temporarily fuse them together to jump start the engine or generator. I mostly charge with solar or shore power, so getting my house batteries charged from the alternator is not a high priority.

[3x5]

Originally Posted by Cinequip

In a Vansco equipped coach, the Boost solenoid is also used to connect the House and Chassis batteries together, to keep the House charged off the Chassis when driving, AND to keep the Chassis charged off the House when plugged into shorepower (or generator running). If you disconnect the left top wire, as Twinboat described, you effectively disconnect the two battery banks from each other, and the alternator cannot charge the house. This will allow you to drive down the road, without worry of damaging the alternator. IF YOU HAVE AN ECHO CHARGER, you'll also need to disconnect the battery cable that goes to the chassis batteries from that. Later model coaches don't have an echo charger, the Vansco took over that task. I'm not sure what year they eliminated the Echo Charger.

Now, as to the BIM vs. DC-DC charger question, I have neither. However, I installed solar on the roof at the same time as lithium batteries. My house batteries are maintained (charged) from solar, or when plugged into shore power through the inverter/charger. I saw no need to also have the alternator charging the house, as I drive only during the day when the solar panels keep the house charged very nicely. I have enough lithium battery capacity to easily power our coach overnight, until the next solar day.

I agree with Paul over the preference of DC-DC charger instead of the BIM, if you were to use one. Once I learned how the BIM works, was the last time I'd consider using one.

If you don't install solar, I suggest installing a DC-DC charger.

One more thing. If you disconnect the solenoid (and echo charger), you'll need to figure a way to trickle-charge the chassis batteries when parked long term. You could purchase a inexpensive 2 amp battery charger/maintainer, or Paul and I have an elegant solution for that, if you get that far.

Cheers.

Thanks for the info. You hit the nail on the head.


We have the Echo Charger and Vansco in our 2005. I will disconnect the solenoid wire like Twinboat said. And also the Echo Charger like you said. Like you, we already have lots of solar, so I will try just that for a while. But I researched it, and I am ready to install the Victron DC to DC charger if I need it. There is lots of info on it. I have no questions on how to do it. Thanks for the recommendation.


I have given up on the Precision Li-BIM. Nobody, not even the manufacturer, can confirm how to hook it up in my rig, so I will be returning it for a refund. Installers I have called don't sell it, and so they don't want to deal with it either.


So yes, now I will have to watch my chassis batteries when we stop for a long time. One reason for the Li-BIM though is that it would have kept the chassis batteries charged when parked long term. Apparently the Victron DC to DC charger will not. Victron solar would trickle charge them, but I have Magnum which won't.


I don't want to have to deal with watching them, so I will need some kind of automatic trickle charger. So I am ready, can I ask what is your elegant solution?


Thanks again for your help.

[paul65k]

Originally Posted by El Chapo

I've had the LiBim in there for about 10 months and 5000 miles. It works great and is the easiest to do. I have done a DC to DC in my Jeep and previous Class C, they aren't near as easy to install and you do lose the ability to temporarily fuse them together to jump start the engine or generator. I mostly charge with solar or shore power, so getting my house batteries charged from the alternator is not a high priority.

I have 2 DC-DC converter/chargers installed and still have the ability to "Fuse" the 2 battery banks together (Temporarily) for starting purposes only.

you do NOT have to give up one to have the other, if done correctly

[Cinequip]

Originally Posted by 3x5

I don't want to have to deal with watching them, so I will need some kind of automatic trickle charger. So I am ready, can I ask what is your elegant solution?

Thanks again for your help.

Search for Amp-L-Start online. It's a simple little box that automatically maintains the chassis batteries, off of the house bank. Doesn't need to be plugged into 120vac.

The thing I like about the Amp-L-Start is that it charges up the chassis battery, and then turns off until the voltage drops to around 12.5vdc, and then charges up again. Unlike a battery charger which maintains a trickle continuously.

Of course you'll need to keep the house battery bank charged up with solar or shore power...

[paul65k]

Originally Posted by Cinequip

Search for Amp-L-Start online. It's a simple little box that automatically maintains the chassis batteries, off of the house bank. Doesn't need to be plugged into 120vac.

The thing I like about the Amp-L-Start is that it charges up the chassis battery, and then turns off until the voltage drops to around 12.5vdc, and then charges up again. Unlike a battery charger which maintains a trickle continuously.

Of course you'll need to keep the house battery bank charged up with solar or shore power...

I would have recommended this up until about 9 months ago, I even have one myself but.......... it was a small company and the owner died, there seems to be no desire for anyone to carry on and they are pretty much out of business at this point