Going LiPoFe4 - Renogy Sale - Page 4

tim myers · 04-20-2022, 08:44 PM

@creativepart Looks good, I too have been kind of agonizing over the installation of a B2B charger for my eventual Lithium batteries. I really don't want to loose my battery combiner relay for those times when I might need it. I had to use it to get the Journey started last February before leaving for Florida, cause it was so cold.

I am really surprised that no one has put a video together on how to wire the B2B with the Aux Start Relay.

Kevin Caudill did something to maintain his, but his coach is too different from mine to glean much from his video.

https://www.youtube.com/watch?v=pFd9Uulo9rY

My Journey has a 160 Amp alternator so I really wonder if I could fry it but everyone says yes, so I should probably listen to them.

What does your final wiring diagram look like.

**creativepart** · 04-20-2022, 09:18 PM

The Li-BIM in the video is a straight replacement for the BIM I removed. It does all you want it to do. But, there are many that say it’s not really adequate. So many decide against it that I decided it must not be the way to go. When you research this topic you don’t see many that have used it and feel it’s the right solution.

I’m pleased with my setup, but once I had the BIM out I could see that this would pretty much just bolt in with some wires being transferred and I did have a few second thoughts about it. Sure would make things easy.

I’m not worried about the AUX Battery switch. Jumper cables can do the exact same thing. Not as conveniently but you don’t need it frequently.

tim myers · 04-21-2022, 07:59 AM

I had somewhat of an epiphany on my Journey, or possibly just a brain fart.

I have a device called a Trik-L-Start that came factory installed. In short it combines the house batteries to the chassis batteries and provides a trickle charge to the chassis batteries anytime the converter is charging the house batteries. It is however limited to a max charge rate of 5 amps. It has three wires, chassis ground, chassis batteries, and house batteries (connected to the downstream side of the house battery relay). Obviously the wires are too small based on the 5 Amp max charge rate, but a B2B charger could be installed in place of the Tril-L-Start, I think.

Another device I found is the Victron Citrix- CT. This device is made to connect Lead Acid Chassis bats to LI house bats, and replaces the factory Battery Combiner. It also limits how much charge is passed from the alternator to the house bats. Not a lot of information on this device, sounds too good to be true.

**creativepart** · 04-21-2022, 09:35 AM

You can add another D2D charger for just the Chassis battery if you wish. I've seem some mentions on line of people doing this. Victron makes some with less output... like 12 amps of charging output.

I've ordered the Amp-L-Start because I don't need a lot of charging for the Chassis battery. The only time I need it is when we do a long term stay on shore power. The Amp-L-Start is just a small trickle charge and that's all I need. The newer versions of this device are LiPo ready and you just change a toggle switch. Seems the always high voltage of LiPo batteries messes with the Amp-L-Start's charging logic.

The Citrix-CT does look good. I wonder why it gets almost no discussion in the online forums. I think it's more popular in boating, but there's no reason it wouldn't work in an RV.

You know, the thing I've found is there is tons of info and discussions on all of these subjects for Class B vans and van conversions. And a little for Class C and Travel Trailers. But almost none for Class A motorhomes. When I started this process I expected there to all kinds of help on the topic but it just wasn't so.

**creativepart** · 04-21-2022, 10:08 AM

I kind of wish I had tried the Li-BIM. Though there are a couple of wires I'm not sure of what to do with and that is another reason why I didn't try it.

The stock BIM has a Genset wire that doesn't have a home on the Li-BIM. Also, the Li-BIM is looking for a connection they call "Sig" and I think you have to run a new wire from there up to behind the dashboard. And that would be a big pain to do.

It's too bad they didn't make the Li-BIM have exactly the same connections as the OEM BIM on the RV. That would really make it plug and play.

With the D2D charger you know you have the correct charge profile for your LiPo batteries without question. No second guessing. So, that's a real plus and for me was the deciding factor.

DavidM · 04-21-2022, 11:07 AM

Some interesting observations packed into this latest post. My comments in bold below:

Quote:

Originally Posted by creativepart

I kind of wish I had tried the Li-BIM. Though there are a couple of wires I'm not sure of what to do with and that is another reason why I didn't try it.

The stock BIM has a Genset wire that doesn't have a home on the Li-BIM. I have no idea what that genset wire does. Is it a heavy #4 or so wire, in which case it may supply starting current to your genset. Also, the Li-BIM is looking for a connection they call "Sig" and I think you have to run a new wire from there up to behind the dashboard. And that would be a big pain to do. The Sig input to the Li-BIM is tied to the Aux Start switch on your dashboard if you have one. It also has a Ign input which turns it on only when the chassis ignition is on (at least for charging the house from the chassis system).

It's too bad they didn't make the Li-BIM have exactly the same connections as the OEM BIM on the RV. That would really make it plug and play. Was the OEM BIM on your coach made by Precision Circuits? If so I agree.

With the D2D charger you know you have the correct charge profile for your LiPo batteries without question. No second guessing. So, that's a real plus and for me was the deciding factor. That also would be the primary reason for me to install a DC2DC charger rather than relying on the on/off cycling of the Li-BIM. How could Li batteries get fully charged with a chassis alternator only putting out barely 14 volts?

I have the Precision Circuits BIM 160 on my 2021 Thor Axis. It works very well and charges the chassis battery or the coach battery depending on which is at a high enough charging voltage. It is hopefully more reliable than the venerable Intellitec BIRD/Trombetta relay system that preceded it. I think you have something in between these two systems on your coach, perhaps made by Precision Circuits. The (Li) BIM 160/225 is very compact and makes for a clean installation.

David

**creativepart** · 04-21-2022, 01:18 PM

Hey David,
No, the genset wire on the BIM is just a 14ga wire. If you look at this post in the link below you'll see my BIM - yes, made by Precision Circuits. The genset wire is labled upper right. The one wire at the bottom left that is unreadable is a ground wire.

https://www.winnieowners.com/forums/...ml#post3916991

There is a large gauge wire that starts the generator. It's on the House side of the wiring that's attached to the BIM. If you look at this post (link below) you'll see the genset start wire it's on the right and has a green heat shrink on it.

https://www.winnieowners.com/forums/...ml#post3916936

When it comes to the Li-BIM the main complaint is that the House batteries don't ever get a full charge using it. But I've only seen a few reviews of it and for a few of the people they think it works much better than just doing nothing and charging off of the alternator.

When you remove the OEM BIM you also have to:

1. Add some way to charge the House batteries while you drive
2. Add some way to charge the chassis batteries on shore power long term
3. Have some plan in mind if you need help starting your RV if the start battery is dead

So, if the Li-BIM charged well, protected the alternator and matched up with the OEM BIM's wiring that would be a great solution.

**creativepart** · 04-21-2022, 01:26 PM

I'm testing stuff out now and seeing what kind of functionality I have. With my AGMs I had difficulty running the microwave even 30 secs. The voltage would drop so much that the Inverter would cut off.

But today, on full house batteries I ran the microwave 2 mins on high. And it was drawing 143amps (1850w) but there were no problems at all. According to my battery monitors (I have three now - Victron, Magnum and Renogy built into the batteries) I went from 99% state of charge to 97% state of charge. Two minutes of microwave used about 5.5ahs out of my 400ah bank.

So, this will change things right away. Currently, when we stop for lunch we have to turn on the generator to use the genset. No more of that. The more we use the system the more we'll be able to see how fast it discharges and also how quickly it recharges as I drive.

tim myers · 04-21-2022, 01:57 PM

I am not certain how my battery combiner really works, there are a lot of wires running to it but only 4 connection points, Chassis Bat +. House Bat +. and two wires that I am pretty sure connect to the switch inside.

I still need to do some research on when that relay is energized, as in chassis connected to house. Maybe when I get back from this trip I will check things out. Almost seems this relay would need to be energized to charge the house side from the chassis side, I need to watch Kevins video again he tried to explain it.

tim myers · 04-21-2022, 02:12 PM

I re-watched Kevin's video and this is what he said

With the ignition switch in the off position the chassis and house bats are isolated

With ignition in the ON position the solenoid is energized and the chassis and house bats are connected

When the ignition switch is turned to the CRANK position the solenoid ie de-energized and the Bats are again isolated from each other.

If during cranking the Boost button is pushed the solenoid re-energized to combine both sets of bats.

Is this is correct that solenoid is getting quite a workout.

tim myers · 04-21-2022, 02:21 PM

I believe the Amp-L-Start is very similar to my Trik-L-Start. I agree with you about no information for our Class A motor homes, that is insane. As for the LI-BIM, I am in the court that feels the charge rate should be controlled and not just arbitrarily cycled on and off, but then that is just me I guess.

**creativepart** · 04-21-2022, 02:49 PM

Tim the one thing you left out in your BIM functions list - well, not with your BIM but definitely with the Li-BIM and the BIM in my newer coach - when the ignition is off and you are on shore power the BIM will charge the chassis battery from the house battery bank - but only when the chassis battery has voltage below 12.5v and the house bank has 12.6v or more.

In other words the newer BIM and Li-BIM work like your Trik-L-Charge.

As I understand it, the main difference between the Amp-L-Charge and the Trik-L-Charge is that the Amp-L provides more amps AND is LiPo capable.

uthurricaner · 04-21-2022, 09:26 PM

Quote:

Originally Posted by creativepart

I kind of wish I had tried the Li-BIM. Though there are a couple of wires I'm not sure of what to do with and that is another reason why I didn't try it.

The stock BIM has a Genset wire that doesn't have a home on the Li-BIM. Also, the Li-BIM is looking for a connection they call "Sig" and I think you have to run a new wire from there up to behind the dashboard. And that would be a big pain to do.

It's too bad they didn't make the Li-BIM have exactly the same connections as the OEM BIM on the RV. That would really make it plug and play.

With the D2D charger you know you have the correct charge profile for your LiPo batteries without question. No second guessing. So, that's a real plus and for me was the deciding factor.

The sig connection is the dash switch(Emer. start), the gen connection wire is not used, the ground is the ground and the ign is the ign. The one thing I'm curious about is what do the battery disconnect relays mount to if you remove the bim?
Sam

**creativepart** · 04-21-2022, 09:42 PM

Quote:

Originally Posted by uthurricaner

The one thing I'm curious about is what do the battery disconnect relays mount to if you remove the bim?

Contrary to how it looks, the disconnect relays on each side of the BIM have their own mounts. The BIM also has its own mount in between the two sides of the relays. So you can remove the BIM and the two relays are firmly mounted.

What you lose when you remove the BIM is the studs at the top of the BIM that the main house and chassis cables and the associated relays bolt onto. But that is easily solved by adding a nut and bolt stud bolted directly to each disconnect relay in place of the BIM.

When you remove the BIM it’s immediately clear what to do. In fact, in the past when I looked at that whole mess of wires it made no sense. But after getting into it it all makes perfect sense. Quite simple actually.

**creativepart** · 04-21-2022, 09:52 PM

Quote:

Originally Posted by uthurricaner

The sig connection is the dash switch(Emer. start), the gen connection wire is not used, the ground is the ground and the ign is the ign.

So, the labeling is all that’s causing the confusion. While the OEM BIM says “Dash Switch” the new Li-BIM says “SIG”? Wow, that would have been an easy install.

Do you have any idea what the GenSet wire is used for on the OEM BIM?

uthurricaner · 04-21-2022, 09:57 PM

That being the case, the li bim would probably bolt right in it's place. You mentioned that the you had read it did not do a good job of charging the house batteries. I can tell you that the bim we have is the same way. I'm not sure what algorithm they use but I've never left a place with partially discharged batteries and arrived at another destination with anything close to charged batteries. I believe they switch off the charging to protect the alternator but the bim has no feedback on amps so it is just time based.

**creativepart** · 04-21-2022, 10:23 PM

Well, not really bolt right in due to its odd shape and size. It might take some “engineering” to fit it in place. But being an optimist I think it could work. But I always think that until I try it and find out otherwise.

**creativepart** · 04-22-2022, 04:20 PM

I hadn't seen this video before, but it answers the questions we are all asking in this thread:

https://www.youtube.com/watch?v=u8wnqlNguYw

DavidM · 04-22-2022, 05:36 PM

That video may have alluded to it but didn't directly answer this question: With a Li-BIM 225 will the chassis alternator fully charge the house lithium battery.

I don't think so.

David

**creativepart** · 04-22-2022, 06:57 PM

Quote:

Originally Posted by DavidM

That video may have alluded to it but didn't directly answer this question: With a Li-BIM 225 will the chassis alternator fully charge the house lithium battery.

I don't think so.

Yes, I think you are correct.

I wonder why they don't go further with that product? Make it do what we all hope it will do. Their sales would go up massively if it did.