Is a DC to DC Charger Really Needed?

[dkoldman]

Originally Posted by Morich

Yes, I have much the same questions on the SIG wire and what it does versus what the IGN wire does? It will likely need a call or talk to somebody who knows what they put in side their product!
Part of it is something I've never looked at and may not be available. Do other RV besides Winnebago use something similiar to what we have on solenoid, BIM, etc?
My thought is that other RV may have a different setup for charging the coach while driving and what we find may not have been what they were working with in their design thinking!
But that is where I tend to have alove /hate thing with solid state! I grew up with the old stuff like points and plugs on cars. they gave a ton of trouble but when they stopped working right, you could use a fingernail file and may the points work again.
Now if I had trouble with my car, I would have little choice but to take it to a shop where they hook it to a machine to find what to do!

On the batteries, do they come with any kind of cold cranking amps (CCA) rating? That is what I use to judge how much instant power we can get, where the amp hours is more how mcuh total between full and discharged.
And that also gets back to the new gizmo being discussed! When you have the current solenoid, there are big contacts that can carry lots of current from the coach to start the RV. But what is in the new and how much current at one time can it pass?
Any engineers for the company that like to explain things???

Watch the video in post #15 from Creative Part. He had two wires and the Boost was on the SIG.

I tried calling Precision Circuits but they are closed until Monday.

I know for TMC BIMs are common, but they have to upgrade to the LI-BIM to do work with Lithium or go to DC to DC

I verified that my coach does NOT charge Chassis battery when on SP, so if the LI-BIM does that is a differentiator. But I don't understand how the LI-BIM can charge the house at Boost 14.4vdc while on SP/Genny but NOT overcharge the Chassis FLA or AGM?

I saw one video today where a guy 3 years insisted the Lithium could not start the engine, but a few folks I talked to disagreed because they say the lithiums work with the starting batter to provide the boost it needs. Maybe if the starting battery was completely dead?

[Morich]

You are correct in the chassis battery doesn't charge from the shore power as when the engine is off and you are not pushing the dash switch, the solenoid is not closed.
One of the good points when they moved to the BIM froms solenoid is the solid state does some "thinking" which the solenoid doesn't.
As I understand the BIM, when the chassis battery is lower than some set point, the Bim will let some current flow to that battery as well as charge the coach.
It is my guess that it has some high and low set points built in that will keep the chassis battery floating at the correct levels without overcharging.
Warning! That is a guess and not from experience with using a BIM system!
Experience with remote sites and batteries, it is comon for the newer/better charge systems to charge heavy when batteries have been down after power failures and then taper off to just enough to float them at the ideal level for the type battery used.

My problem with lack of knowledge in much depth is that they tend to work so well and never fail! When I learned the most was when things failed and they had to be fixed!

[bigb]

The lithium batteries don't make for good starting batteries but if I ever need to use the boost I'm hoping by holding it on for a while it will charge the chassis battery enough to crank the engine.

[dkoldman]

Originally Posted by bigb

The lithium batteries don't make for good starting batteries but if I ever need to use the boost I'm hoping by holding it on for a while it will charge the chassis battery enough to crank the engine.

Makes sense. I have sent a list of questions via email to Precision Circuits Tech Support. Hopefully I learn more next week.

Have you ever encountered this...

Per WBGO Operating Manual, I have always ran my engine when working the hydraulic jacks and / or slide. But with this LI-BIM 225, it is possible that engine could be running but alternators not supplying the batteries or worse it is supplying full voltage/current but goes into rest state to cool the alternator in the middle of operations.

I believe the Jacks run off Chassis and the Slide off House?

[Morich]

We don't get a really clear drawing of much of the chassis but I don't see slide power on coach, so went looking at chassis?
You have motors instead of rams for the slide, so that throws some doubt on this as it shows powers to slide rams? We get this info from this set of drawings:
https://www.winnebago.com/Files/File.../000126353.pdf

Seems a little flaky , looking at the drawings but maybe you can check if it is right? They label power for rams but you have motors?? HUMM!
They show front for location. But there are a few open holes to match to get it all matched right!

Click these snips for better view!

Front view

Then if we want circuit ID, we need to mentally turn the panel around left/ right and count from the other end!
Back view!


Looking at the ID chart here:
https://www.winnebago.com/Files/File...ical_guide.pdf


I feel this will be slide power working off chassis but some of the labels and ID are not clear to me. part of it calling them ram power seems hydraulic and you have motors. The red are spots where no breaker is shown but there are labels shown for that vacant hole??

But maybe it looks better in person?? I'm saying slide power is from chassis but with questions!!

[dkoldman]

Originally Posted by Morich

We don't get a really clear drawing of much of the chassis but I don't see slide power on coach, so went looking at chassis?
You have motors instead of rams for the slide, so that throws some doubt on this as it shows powers to slide rams? We get this info from this set of drawings:
https://www.winnebago.com/Files/File.../000126353.pdf

Seems a little flaky , looking at the drawings but maybe you can check if it is right? They label power for rams but you have motors?? HUMM!
They show front for location. But there are a few open holes to match to get it all matched right!

Click these snips for better view!

Front view
Attachment 189344
Then if we want circuit ID, we need to mentally turn the panel around left/ right and count from the other end!
Back view!
Attachment 189345

Looking at the ID chart here:
https://www.winnebago.com/Files/File...ical_guide.pdf
Attachment 189346

I feel this will be slide power working off chassis but some of the labels and ID are not clear to me. part of it calling them ram power seems hydraulic and you have motors. The red are spots where no breaker is shown but there are labels shown for that vacant hole??

But maybe it looks better in person?? I'm saying slide power is from chassis but with questions!!

I kind of assumed the Jacks were on Chassis but the Slide was on house. I can't find proof. I could try to get the RV out and turn off the House Disconnect to see if it Open up? I may be getting the Slide on House with Genny on House.

I sent some questions to precision circuits about the LI-BIM although I think I have the answer to one of them. It looks like the LI-BIM will always send power to the Chassis battery so the 20 minute timeout is only for the House battery. So I should not have to worry about my jacks losing current when engine and possibly the slide if it is in fact on Chassis battery too.

My questions to Precisions Circuits

1. My current wiring had the Ignition and the Boost Hot on the same wire 'LR'. If I connect that wire to your IGN post; will it be okay if the SIG post is empty? The ground, chassis and coach cables will be connected. Will it work that if I hold AUX/START I can use the Lithiums to help start the chassis battery

2. How does the LI-BIM 225 prevent overcharging the Chassis battery when on SP/Genny when the House battery is calling for full boost 14.4vdc?

3. If I have the LI-BIM 225 installed, how do I ensure that it will not go into rest state or come out of rest state in order to operate the Hydraulic Jacks and/or Slides? Currently per Winneabgo operating manual, the engine must be running to operate Jacks and/or slides. This is to ensure the alternator is running so full voltage / current is applied. Seems like with LI-BIM 225 it could happen to go into a rest state right in the middle of operations. Is there something to prevent or ensure max power before operating?

[Morich]

That is really where I would have to ask the same questions. The nice thing about solid state is also one of the bad things!
They can put together any number of small parts to make it do lots of really great things and in really small packages. But that is also what makes it impossible to see feel or test what any of those small parts are doing or even making a good guess as it is all poured into a solid package. Not even a cover to take off and look!

Progress can be great but not if you are wanting to make changes!~

[creativepart]

Originally Posted by dkoldman

what I am still confused about is SIG?

Also, is the AUX/START button irrelevant with Lithiums on House? Not sure 200ah Lithium can start the F-53 engine?

Once Precision Circuits opens next week they should be able to tell you what wires go where. I got the "impression" that the SIG wire was the Aux Start wire. But I don't know if that's correct.

There are a lot of videos about installing the Li-BIM on YouTube. Watch a few more and see if others can give you more clarity on the connections.

I made the decision to eliminate the Aux/Start function. I had only used it once and felt I could use auto jumper cables to achieve the same function.

But then I put that to the test immediately - since I didn't use the LI-BIM I severed all connections between the house and chassis batteries. As I was working on this and other projects the RV sat in my driveway for a week - plugged into shore power. But I left the Chassis battery disconnect on that entire week and sure enough the chassis battery died and could not start the engine.

So, I connected my car (also my Toad) battery to the chassis battery of the RV. It took about 15-mins to have enough power to start the RV. But it worked. I didn't try running the jumper cables from the new LFP batteries to the chassis battery so, I don't know if that would work.

To prevent this from happening in the future I bought an "Amp-L-Start" device connected it between the chassis and house batteries. This $140 device takes some power from the house batteries and uses it to keep the chassis battery charged. Years ago this was a very popular addition on Winnebagos - before they changed to a BIM that did that task automatically.

Unfortunately, the company that makes them was a one-man outfit and he suddenly died. So, sales stopped about 1 1/2 years ago. Though I hear someone else has introduced such a device.

Losing the Aux/Start feature is one of the reason's I wish I had installed the Li-BIM when I installed my LFP batteries.

[Morich]

The problem with being the new owner of the Trik-L would be the limiting factors for long term. As BIM and various versions become the big idea in most new RV, the sales for add-on items to do the same job will get less and less every year as the older rV without fall away.
It would first seem a good business to replace the old, but then who wants to invest in a fading sales item? A bit like investing in a machine to remove seeds from watermelon at the same time seedless melons hit the market!

[dkoldman]

Originally Posted by Morich

That is really where I would have to ask the same questions. The nice thing about solid state is also one of the bad things!
They can put together any number of small parts to make it do lots of really great things and in really small packages. But that is also what makes it impossible to see feel or test what any of those small parts are doing or even making a good guess as it is all poured into a solid package. Not even a cover to take off and look!

Progress can be great but not if you are wanting to make changes!~

I just pulled the RV around, drop the jacks to auto level with engine running as I ALWAYS do. Then with engine still running, I turned off the House Battery Disconnect switch, then went to let out slide crickets. If this had been real world I would have pissed in my pants out of fear before the I realize the House Disconnect switch was off. So Activate the House batteries and slide extended all the way out, I brought back in as point is made.

On my 2019 Sunstar 29ve

House Batteries control the Slide & Genny
Chassis Battery control the Hydraulic Jacks

I read my operating manual again, the instructions are clear. The Engine, ShorePower or Generator must be ON to operate the Slide or Jacks.

So I conclude if I have LI-BIM, I could start randomly using my slide without the alternator providing full voltage/current to Slides. I would have to wait until I had SP hookup or turn on the genny to operate the slide to be sure

So I trade risk of damage to the Alternator to risk of Damage to the Slide. Unless Precision Circuits can tell me how to force the alternator current to flow through. But that effort may be more than starting Genny or SP. But if it is late night, I may not be able to start genny and I may not have SP.

[dkoldman]

Originally Posted by creativepart

Once Precision Circuits opens next week they should be able to tell you what wires go where. I got the "impression" that the SIG wire was the Aux Start wire. But I don't know if that's correct.

It was in the video you supplied. It was looking so simple. Then I saw I only have one wire ("LR") in picture and it looks as if it will be hot when ignition is on or if Aux/Start is pressed. The more I think about it, I believe the LI-BIM would contact the Chassis to House either way?

There are a lot of videos about installing the Li-BIM on YouTube. Watch a few more and see if others can give you more clarity on the connections.

I have watched a number of them now, yours was the best with info thus far. I will see what Precision says. Precision's website is borderline useless

I made the decision to eliminate the Aux/Start function. I had only used it once and felt I could use auto jumper cables to achieve the same function.

But then I put that to the test immediately - since I didn't use the LI-BIM I severed all connections between the house and chassis batteries. As I was working on this and other projects the RV sat in my driveway for a week - plugged into shore power. But I left the Chassis battery disconnect on that entire week and sure enough the chassis battery died and could not start the engine.

So, I connected my car (also my Toad) battery to the chassis battery of the RV. It took about 15-mins to have enough power to start the RV. But it worked. I didn't try running the jumper cables from the new LFP batteries to the chassis battery so, I don't know if that would work.

To prevent this from happening in the future I bought an "Amp-L-Start" device connected it between the chassis and house batteries. This $140 device takes some power from the house batteries and uses it to keep the chassis battery charged. Years ago this was a very popular addition on Winnebagos - before they changed to a BIM that did that task automatically.

Unfortunately, the company that makes them was a one-man outfit and he suddenly died. So, sales stopped about 1 1/2 years ago. Though I hear someone else has introduced such a device.

Losing the Aux/Start feature is one of the reason's I wish I had installed the Li-BIM when I installed my LFP batteries.

If I go to DC to DC, I will keep my Trombetta in place as it is, I will then go to one of the 3 options Morich has given me on a switch in front of the solenoid on Ignition wire 'LR" That switch will be in my lower bay compartment next to Chassis breakers. It will always be OFF if I have DC to DC, then if I need to use Aux/Start (and I have needed it too) I will simply go flip that switch and then go back to the cab and Press Aux/START to start or transfer power.

[dkoldman]

Ok, while I wait on more info from Precision Circuits LI-BIM

I am proceeding as if I may have to go DC to DC to check all of the boxes.

I am looking at the Renogy 40amp unit that is all I need for my 200ah batteries I am looking at)

Question now is where might it go? Earlier Morich had me thinking it could go on driver close to trombetta. That would be good because I could leverage the Ignition wire. But since I don't intend to disconnect the stock OEM wiring, not sure if I can find the chassis positive & negative input for it nor the house positive & negative for the Renogy Output.

If the above is not possible, I would then need to see if I have an existing ignition wire near the battery compartment. I want to say I have an ignition wire running on that side that goes to the AGS? The AGS has a safety feature when ignition is turned. Not sure is it just accessory position or full start?

[Morich]

Small quick point on having the two batteriy and negative? Negative is just ground, so lots of metal will do the negative sides of either as they are both run straight to frame ground.
Then you Do now have both coach and chassis battery cables on the Trombeta, one on each big lug!

Gotta go for now.

[creativepart]

I'm pretty sure, when you start the engine the Li-BIM connects both battery banks to the alternator. Then it starts its "timer" from that point.

I put my Victron DC2DC charger in my Battery compartment. I have it wired directly to my chassis battery under the stairs on the other side of the RV. Since the Victron is only 30-amp I just used 8ga wiring - 10ga would have worked as well.

The best thing about the Victron Orion is the auto sensing start/stop. No complex wiring to the ignition switch is needed simplifying installation.

Here's my DC2DC charger:

[dkoldman]

Originally Posted by creativepart

I'm pretty sure, when you start the engine the Li-BIM connects both battery banks to the alternator. Then it starts its "timer" from that point.

I put my Victron DC2DC charger in my Battery compartment. I have it wired directly to my chassis battery under the stairs on the other side of the RV. Since the Victron is only 30-amp I just used 8ga wiring - 10ga would have worked as well.

The best thing about the Victron Orion is the auto sensing start/stop. No complex wiring to the ignition switch is needed simplifying installation.

Here's my DC2DC charger:

The Orion 30amp is nice, I got a tad confused with isolated / non-isolated although I don't my coach is isolated so I would have needed non isolated but 12vdc to 12vdc were either hard to find or very expensive.

I had a Renogy 40amp fall in my lap. It was brand new and I made a really low offer and the guy counteroffered only $10 more so I just bought it. I got right at $100 including shipping & tax.

I may encounter space issue when trying to mount near solenoid, but I will play with it and see. I agree on the ignition wiring, Renogy should know, worse case if I don't find something in battery compartment, I can run a wire to tap into LR alongside the existing wire loom. The switch will have to be in compartment with solenoid on a cabinet wall.

On the LI-BIM, I suspect it will run the 1st 10 minutes, but when I extended slides, it usually after a trip, I don't naturally turn the engine off and restart. I just don't want to add to my checklist trying to ensure alternator is running before using slide. Making sure the jacks are down, engine is running, everything is clear, the bathroom door is in right locations, and no one is sitting on sofa is enough. I don't want to tell the wife now check the voltage level. Even if it were 14.2, that LI-BIM may hit that 15 minute limit.

I will still listen to what they have to say, I may be missing something.

On the SP/Genny charging Chassis, I don't have that today, so I will not miss it tomorrow. Ironically as long as I ensure the AUX/START function it may be a good think the the Chassis battery is not constantly being charged. My Chassis battery is 6 years old and still going. I don't see much to fix / improve there. If I had great but it is not a factor for me.

[Morich]

Have you had time to look at your breaker panel out by the solenoid? Since you find the slides die when coach power is turned off, I reallly get questions on what portion of the drawing I posted is even correct for your RV?
I had some doubt when I see all those breakers for differen trams.
To me ram means hydraulic rams. I'm not thinking how it could ever mean the motors you have to move the slide. But that throws the labels and breakers for rams into real doubt ??

Did your RV model use hydraulic at one point and they failed to change out the electrical drawings to show that change or am I just confused about the whole idea?
It would not be the first time I've found mistakes in their drawings but then it would not be the first time I was confused, either!

[dkoldman]

Originally Posted by Morich

Have you had time to look at your breaker panel out by the solenoid? Since you find the slides die when coach power is turned off, I reallly get questions on what portion of the drawing I posted is even correct for your RV?
I had some doubt when I see all those breakers for differen trams.
To me ram means hydraulic rams. I'm not thinking how it could ever mean the motors you have to move the slide. But that throws the labels and breakers for rams into real doubt ??

Did your RV model use hydraulic at one point and they failed to change out the electrical drawings to show that change or am I just confused about the whole idea?
It would not be the first time I've found mistakes in their drawings but then it would not be the first time I was confused, either!

I did look at earlier. The drawing you have is correct. There was another drawing of full body electrical that referred to the panel as the Chassis Panel (Box)

The first 5 with SLIDEOUT RAM have dummy plugs, the 6th one is in use, I assume it is for my Hydraulic jacks that I do have. I have not opened that panel today because I know there are a lot of wires back there and easy to short something as it is so much metal. But I know there is a 12v buss bar, I assume it is from Chassis, in fact I know this because Pin 9 on a connector goes to my Kwikie step that should still work if House switch is OFF. I believe it was wire RS? It was the key to the mystery of my steps that WBGO Dealer never could find the issue, when they charged me for troubleshooting I paid and have never been back. I fixed it myself about 3 months later.

I am sure I made the right choice with Renogy DC to DC to maintain guaranteed voltage supply to my Slide off the house battery if I ever go Lithium, but I may be challenged to find where a 10"x7"x3" charger will go.

This may be a long journey for me as I try to design the end state. I have time because my AGMs are okay right now. But I would like to go to Lithium BEFORE the AGMs are no longer ok if that makes sense,

[dkoldman]

So I pulled the Chassis Panel Cover off. I don't have the Renogy 40amp but I know it is 10.3 x 6.9 x 2.7 in

Is it something that can go inside this panel with Trombetta?

From the size the only way it might fit would be to mount upside down in ceiling or right side up on the floor. It might possibly fit on the side walls if rotated vertical, but on the side closest to compartment door would have the screws protruding out so it is not practical.

It is all mute if it can't go inside.

If it can go inside, and size is an issue, the Victron Energy 30amp unit is 3 inches shorter. In this area I think all of the wires needed are right there

Renogy Input => Chassis Positive = Connect to Chassis post on Trombetta
Renogy Input => Chassis Negative = Need to find Frame for ground
Renogy Output => House Positive = Connect to House post on Trombetta
Renogy Output => House Negative = Can connect to same Chassis Negative on Frame
Ignition = Connect to LR wire via splitter in front of Trometta

[Morich]

Yes, time to take time to get the best result!
I missed reading th edrawings as they are shown at an angle and threw me way off on which breaker went under which label. So did they get their labels to match what it looks like now?
I think it goes like this from the front:

This looks right for size of fuse being right for load it has! The two at far right are 55 and 30 as they feed to other fuse panels. Mains leading to sub panels?

Then if we look at the back that show four different buss bars with different feeds ID'd at bottom and feeding differing numbers of smaller loads ID'd at top!


NOT just a simple buss bar in the panel but four bars doing different things.
Lots more complex than the normal house panel!

But maybe it never gets into trouble and you never have to know!

[Morich]

Originally Posted by dkoldman

So I pulled the Chassis Panel Cover off. I don't have the Renogy 40amp but I know it is 10.3 x 6.9 x 2.7 in

Is it something that can go inside this panel with Trombetta?

From the size the only way it might fit would be to mount upside down in ceiling or right side up on the floor. It might possibly fit on the side walls if rotated vertical, but on the side closest to compartment door would have the screws protruding out so it is not practical.

It is all mute if it can't go inside.

If it can go inside, and size is an issue, the Victron Energy 30amp unit is 3 inches shorter. In this area I think all of the wires needed are right there

Renogy Input => Chassis Positive = Connect to Chassis post on Trombetta
Renogy Input => Chassis Negative = Need to find Frame for ground
Renogy Output => House Positive = Connect to House post on Trombetta
Renogy Output => House Negative = Can connect to same Chassis Negative on Frame
Ignition = Connect to LR wire via splitter in front of Trometta

Sounds right but I'm no help on the size!
Getting space may be a problem and one to consider is how to get to the Trombetta and battery disconnect if there were ever a real need. The solenoid is know as a potential troulbe spot as it opens/closes every time we start the engine and that causes small arcs every time. Not to say it fails soon but you may at some point want to get there, so nothing permanent that blocks the path?
One point on the grounding is that most any metal of the box/compartment is likely welded to the rest of the metal, so no need to go to actual frame of the RV. Basic idea is to keep all grounds at the same level but most of the solid parts are attached to the frame. Things like their major buss bars are often welded or bolted direct on the frame. The copper buss bars is something they can make all the holes for the smaller wires and then attach it to the frame but there are often at least two!
Maybe just clear the paint off at a handy point and then makes sure the attachment bolt, etc. is never coming loose?
Second thought? That wire FM is laid on the mounting screw of the Trombetta and they use the mount as ground as well as the wire, so double on the same point would be good!
Test before trusting!