Slides on house batteries

[JimStreit]

Hello all, I have a 2007 Tour 40TD with lithium house batteries and 840 watts of solar. I want to reduce the amount of stuff coming off the starter batteries since the house are always stronger, and just leave the starter batteries for starting.

Has anyone changed the wiring so the slides are extended/retracted off the house batteries? I've been looking over the electrical plans from Winnebago but haven't figured it out just yet.

Thanks.

[Morich]

One simple fix for the question of running down the start battery when moving the slide is to just start the engine first.
The battery is just a storage space and if we have the engine alternator running we don't take anything out of the storage!
Many manuals do recommend this for moving the slides or jacks.

[Reniram]

A wise man told me that running the engine while extending the slide puts extra voltage to the slide motors..evidently if the engine is not running only 12 or even less volts ( if the battery is not new) are going to the slide motors which is not optimal...I am not an electrical wizard but it did make sense when he explained that running electric motors at reduced voltage causes overheating which is not good .

[Morich]

On secondlook and spotting the lithium batteries mentioned, that means massive changes have likely been made, so the manuals and "normal" are no longer a factor!
Much depends on what mods were made and how well thought out those mods were.

[JimStreit]

I have made some changes. I took out the original inverter and have replaced it with a Victron Multiplus II, added a Victron 100/50 MPPT solar charge controller and have replaced the three house batteries with 100ah Battleborns. With the solar or shore power the house batteries are almost always full or close to full, between 13-14 volts and triple the capacity.

My thought is less diesel run time (noise and odor) in the campground for setup and teardown. Additionally, a couple of my jacks are slow to retract which adds to the overall time I'm sitting there idling. Not usually a big deal in the afternoon but sometimes we like to get rolling early in the morning and I'm sure the neighbors would appreciate it.

[bigb]

My manual states to run the engine when operating the slides or the recliner pedestals, but I don't. First, it probably takes more from the battery to start the engine than it does to extend 2 slides 24" or a raise a seat pedestal and secondly I have a Bluetec engine and idling is not recommended. I doubt the few seconds it takes to move the slides out will be cause for enough heat to damage the motors. I've often thought about installing a 3 way switch to have the slides use the coach batteries when I want, like when plugged in. My other thought is to install a 15 amp Victron Blue smart charger on the chassis battery plugged into a coach electrical outlet so it would charge the chassis battery when operating the slides (whenever plugged in).
Just curious how many here actually do run the engine when operating slides?

edit: A quick Google search shows much inconsistency on manufacturer's recommendations and in fact many slides will not operate at all with the engine running.

[Reniram]

I can only go by the recommendations of the manufacturer by running the engine (Ford gas V10) which gives a healthy output direct from the alternator. When our 22foot slide operates, almost all the side of the motorhome is moving and I can only imagine that it takes quite a bit of energy to accomplish this feat. So far after almost 4 years we have not had any hiccups...fingers crossed....The same applies to the levelling system as there is always a certain amount of nervous tension during these procedures...I certainly dont know enough about the electrical circuits to install extra power or bypass stuff but I do know there are electrical wizards out there that understand and know what they are doing..I am sadly lacking in that department.

[Morich]

Originally Posted by JimStreit

I have made some changes. I took out the original inverter and have replaced it with a Victron Multiplus II, added a Victron 100/50 MPPT solar charge controller and have replaced the three house batteries with 100ah Battleborns. With the solar or shore power the house batteries are almost always full or close to full, between 13-14 volts and triple the capacity.

My thought is less diesel run time (noise and odor) in the campground for setup and teardown. Additionally, a couple of my jacks are slow to retract which adds to the overall time I'm sitting there idling. Not usually a big deal in the afternoon but sometimes we like to get rolling early in the morning and I'm sure the neighbors would appreciate it.

This does seem like it changes the question, so maybe some more thought is needed?
Some questions to speed it along with looking it over will help.
1. I see the latches for locking the slides. Do you have three slides?
2. Are the latches and slide movement controlled by a seperate on/off key?
3. The do slides and jacks share a common hydraulic pump?

If unsure, I can dig more and possibly find things but if you know, that moves the question better as well as quicker than me searching for answers with all kinds of room for error!

We do get far more of the chassis wiring on your RV than many give us.

[creativepart]

Originally Posted by bigb

Just curious how many here actually do run the engine when operating slides?

edit: A quick Google search shows much inconsistency on manufacturer's recommendations and in fact many slides will not operate at all with the engine running.

I run the engine when operating the slides and the levelers. The amps pulled from the batteries when the slides are moving will drop your battery’s voltage to dangerous lows - bad for the slide motors and bad for your batteries.

In my opinion you should not even consider ignoring your Operations Manual on this point.

As for what other manufacturers state as their procedures? Who cares? Their info doesn’t apply at all.

[bigb]

Originally Posted by creativepart

I run the engine when operating the slides and the levelers. The amps pulled from the batteries when the slides are moving will drop your battery’s voltage to dangerous lows - bad for the slide motors and bad for your batteries.

In my opinion you should not even consider ignoring your Operations Manual on this point.

As for what other manufacturers state as their procedures? Who cares? Their info doesn’t apply at all.

My manual says "We recommend running the engine when operating the slides so the engine alternator can provide maximum power for proper operation of the slideout mechanisms."

It doesn't say damage may or will occur, nor does it say this is required, only recommended.
I don't see where running a DC motor on a lower voltage will be detrimental to it unless it is allowed to stall, in fact DC motor speeds are controlled by changing voltages. I'm sure the reasoning for the recommendation is to prevent poor slide operation due to Winnebago having no control over battery conditions as they age out in the real world. The average owner is not on top of their battery condition like some of us. As a matter of curiosity if I have some spare time today I am going to monitor voltage with engine on, engine off and engine off/battery charger on.
As far as trusting Winnebago engineering, I don't. Not after all the issues I found for example venting the propane fumes from the fridge directly into the fridge compartment (which was not properly sealed from the living quarters) in violation of the installation instructions, and how about the 18 feet of #12 wire they ran to the 12 volt element resulting in 10.9 volts at the fridge with the engine running?
I think mentioning that some brands do not say to run the engine, or are prevented from operating with the engine running, certainly does apply to a thread where engine on or engine off is being discussed.
Finally, Mercedes warns against unnecessary or extended idling which is my main reason to not keep the engine running while I set up. I am not too worried about putting my 2 small slides in and out for as short of period of time it takes on battery power alone but like I said I am going to do a test just to see what happens with the voltages, which may also help the OP see the difference when his coach batteries are operating a slide while under charge.
My guess is that the engine starting load will leave the battery more depleted overnight than running my 2 little slides out.
Also protecting my Bluetec engine is a big priority for me, I've seen what can happen when folks don't stay in tune with that, usually because they aren't aware of it.

[Morich]

After looking it over for a bit, I might sugggest a different way of thinking how to get the slide operation to use coach battery instead of start battery and without starting the engine.
When we start the engine we do get better power to the slides but , in this case where the OP does have a reason to avoid starting the engine, there is a different way to go.

Since the lithium batteries are connected together with the start when we drive, the potential for harm in doing it for a short time while we move the slides is small enough to ignore.
Power always moves from higher potential to lower and will move faster/ more current from a higher potential than a lower. That's just basic electronics.

If we push the boost or aux switch on the dash, both sets of batteries will connect together but without the engine starting, we do not get the added power from the alternator but with the info the OP has given us, it can be assumed the litium batteries will give good power.

So is it practical, due to location of the various switches, to just push the boost/aux switch and then move the slides? That woud be the simple , no fuss, way to get it done as the larger portion of the power WILL come from the higher voltage lithium battteries and little from the start.
I would guess that when the engine starts, there is a fair amount of current rushing from the lithium to the start battery as they connect. But the way batteries take time to charge, it is probably nothing to be concerned about.
If it works currently while driving there is no worry about doing it during the short time we need to move slides!

But if the switches are not located close enough and a "helper"is not handy, an alternate but easy move would be to either replace the momentary boost switch with a standard on/ off switch which is not momentary.

This might have some hazard due to forgetting they are connected and that could let us run both sets of batteries down while dry camping. A "safety light" LED to alert us that they are connected might also be added??

But what works better does depend on those small details!

Correction/alternate thought?
Does the mode solenoid pull up/operate when the boost switch is pushed or does it pull when simply moving the ignition switch to run but not start?
Some testing may help.


I

[Wayne M]

Originally Posted by bigb

My manual states to run the engine when operating the slides or the recliner pedestals, but I don't. First, it probably takes more from the battery to start the engine than it does to extend 2 slides 24" or a raise a seat pedestal and secondly I have a Bluetec engine and idling is not recommended. I doubt the few seconds it takes to move the slides out will be cause for enough heat to damage the motors. I've often thought about installing a 3 way switch to have the slides use the coach batteries when I want, like when plugged in. My other thought is to install a 15 amp Victron Blue smart charger on the chassis battery plugged into a coach electrical outlet so it would charge the chassis battery when operating the slides (whenever plugged in).
Just curious how many here actually do run the engine when operating slides?

edit: A quick Google search shows much inconsistency on manufacturer's recommendations and in fact many slides will not operate at all with the engine running.

In the above you reference a Bluetec Engine idling not recommended. I'm slightly confused. It takes less than 2 minutes to put out my 3 slides. I have sat at intersection traffic lights much longer than that with no adverse affect on my non-bluetec engine so I'm wondering how Bluetec factors in the many times an RV has to stop and wait. Another example would be in a traffic jam. Just recently we went 5 miles in 1 hour 15 minutes. Much of that was at a stop for 5 or more minutes.

I know nothing about Bluetec and basically this is the first I ever heard of it. Just wishing to be informed. Thanks.

[bigb]

Originally Posted by Wayne M

In the above you reference a Bluetec Engine idling not recommended. I'm slightly confused. It takes less than 2 minutes to put out my 3 slides. I have sat at intersection traffic lights much longer than that with no adverse affect on my non-bluetec engine so I'm wondering how Bluetec factors in the many times an RV has to stop and wait. Another example would be in a traffic jam. Just recently we went 5 miles in 1 hour 15 minutes. Much of that was at a stop for 5 or more minutes.

I know nothing about Bluetec and basically this is the first I ever heard of it. Just wishing to be informed. Thanks.

Yes in my case it only takes 5 to 6 seconds per slide, but when we roll into camp we are not ready to put the slides out immediately, we need to level and hook up water and power. I like to hook up before putting out the bedroom because it is directly over the compartment where my hookups are and makes it more difficult to access. So I shut the engine off. Re-starting, as I mentioned, likely takes more battery than the slides take and the short runtime is not going to re-plenish that. I could just leave the engine idle but it would rush me and I don't want to do that. I am pretty content to keep doing it this way and as I suspected, the slides use very little power according to my first test this morning. After I am finished testing I will report back.
I realize many have large and heavy slides that will no doubt use much more power than my tiny slides and what works for me will not work for everyone.

Unfortunately excessive idling is not good for any diesel with SCR emissions and yes it can happen that we get stuck in traffic but for the most part if I see more than a few minutes of idling in my future I will shut down. If in a traffic jam on the highway I will run the dash air and nudge the idle up.

[bigb]

Tested in 3 modes, battery alone, battery while on 5 amp Smart Charger, and finally with engine running. Tests were 3-4 hours apart. Lowest voltage while on battery alone was 12.6. With charger on or with engine on voltage was definitely higher as to be expected. When on charger the first operation dropped the volts to 13.1 which woke up the charger and it switched to absorption raising voltage to near 14 for the rest of the operations. Engine running yielded the highest at 14 and most stable voltage which was also to be expected.
The duration was not real scientific, I simply counted one thousand one, one thousand two etc. but there was no noticeable difference in duration or the sound of the motors on any power source.
I do not know what the voltage rating is on the motors, 13.5 or 12. It seems like it would be 13.5 but all the research I did on slide motors shows the rating at 12VDC, unless the advertising specs are confusing rated voltage and nominal operating voltage. I may try and get a look at one of my motors for a label.
I do not see a problem operating the motors at 12.6 volts but I still plan to install an on board Smart Charger for the chassis battery which will power up automatically when the rig is plugged into shore power.
If anyone disagrees with my assumptions and has factual information I am all ears, I am not here to argue and always willing to learn.

[Wayne M]

Understand.Thanks.

[dickb46]

Well, that sure answered the OP's question.

Jim, I have a 12' slide that sets into a flat floor. Putting it out doesn't take anything in the way of power but pulling it back in is like catching a shark when your fishing for trout.

I slide that tank out as soon as I'm parked then shut down the engine because it doesn't take a lot. When breaking camp I start the engine and do breakdown chores while the air blows up then pull the big slide in. It creaks and groans while lifting and sliding but it slowly comes in. The engine batteries are 5 years old and don't appear to be suffering so I'm not thinking of fixing the "problem".

dick

[cruizerEd]

I have LiFEP04 also. With the higher voltage they are excellent for operating the slides. I generally move the slides with the engine running since it is typically already running having just parked or getting ready to move.

If however I want to move the slides without the engine I have my wife hold the "battery boost" switch which combines the two banks and raises the chassis to 13+ volts. The current from the house batteries is about 60A so nothings going to heat up for the few seconds it takes to put the slides out.

Without changing anything you have the flexibility of basically using either bank or both.

[JimStreit]

Hi All,
Thanks for the suggestions and insight. We've been using the boost button the last few times and things seemed to run better, which is what lead me into thinking about switching to the house batteries in the first place. My slides drop to be level with the floor. Dickb46 you are spot on ... putting the slides out only takes about 7-8 seconds and doesn't seem like it needs a lot of effort. Bringing them in is another story, and it takes some power to get them to pop up and start coming in. What takes the longest amount of time is bringing in the levelers. For my rig it takes a good 5 minutes before they retract all the way. This is where I'm really looking to avoid the idle time, but as it was mentioned, I have to let it idle anyway to air up the suspension.

The update is that after digging through a number of electrical diagrams that Winnebago has posted online, I was able to find how to make the change. It was very simple in my situation.

There is a red power line with a blue band that is attached to one side of the boost solenoid that is specific to the hydraulic pump. On the other side of the boost solenoid is the house battery. I simply moved the red (blue band) wire to the other side of the boost solenoid with the house battery. It works great.

[JLUSoCal]

Originally Posted by Morich

Correction/alternate thought?
Does the mode solenoid pull up/operate when the boost switch is pushed or does it pull when simply moving the ignition switch to run but not start?
Some testing may help.


I

I have two USB chargers that show voltage in my dash for the respective battery banks. The voltage goes UP when I simply turn on the ignition (run position BUT not started) on my 2017 29ve. Depending on "if" i need to have the engine running anyhow, I don't worry about starting anymore IF the batteries are connected (i have 200ah or lithium).

Likely model dependent but also has me wondering IF the lithiums are also helping to start the engine - something they're not really designed to do but with three batteries I'm sure it is OK. I have Lion Energy that can do 100 amp discharge each and I also assume that the built-in BMS will kick the batteries off if needed - but so far over the past 2 years no problems.

[creativepart]

JLUSoCal, if you have your RV setup to charge the LiFePO4 batteries from the alternator then any time you turn the key to run you are connecting the house and chassis battery banks. (Note, if the chassis battery was dead this would not have the same effect - in case you're wondering.)

Many of us have removed the battery isolation manager so that the alternator doesn't charge the house batteries. So, that depends on your setup.