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Running Class A RV Leveling Jacks With A 24v Solar Battery Bank

Olecram93

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May 31, 2021
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Hello, newcomer to RV and solar here.

I Have a 2017 Thor Ace Class A that I will be installing solar in using the following:

-Growwatt 24V 3000w
-16 280ah Cells DIY batteries in a 8s2p for a total of 560ah at 24v.
-Victron Orion 24v to 12v 70A and 85A Max step down converter.

The issue I'm having is that the leveling jacks are currently wired directly to the stock house batteries which are 12v and i don't think the step down converter on the 24v setup would be able to handle the load since they pull up to 160 amps at times.

Is it recommended that I wire the leveling jacks to the chasis battery directly and just run every other 12v load through the step down converter?

Thanks in advance for the help.
 
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Many motorhome's leveling jacks are wired to the chassis' battery (JIC) so that they can be retracted and the vehicle driven.
 
This might be why some people will run the RV engine while leveling.

If you want to do this "engine off" and run it off the starter battery, one approach might be to use something like a 75 amp iota charger and plug it into the inverter to help supplement / recharge.
 
Is this the stock setup? Why are you suspecting its the "step down converter"?

160A x 12.8V = 2048 watts? That sounds like a LOT for jacks.
Yes it is the stock setup. Maybe I didn't make myself clear.

The MH comes from the factory with the leveling jacks wired to the house batteries directly. My plan is to convert to 24v, but by doing that I would need to convert down to 12v to keep the leveling jacks powered, since they draw so much I wouldn't be able to power them through the step down converter.

Does that make more sense now?

I want to run 24v in the solar/house battery system while trying to keep everything as close to stock as possible.
 
This might be why some people will run the RV engine while leveling.

If you want to do this "engine off" and run it off the starter battery, one approach might be to use something like a 75 amp iota charger and plug it into the inverter to help supplement / recharge.
In mine, ignition has to be on in order for the leveling jacks to work. I don't mind running the engine while leveling. My leveling jack pump is right next to the house batteries so maybe that's why they wired them like that from the factory.

If I could wire the leveling jacks directly to the chasis battery in the front of the MH, the rest of the 12v loads of the entire motorhome should be able to run through the 24v-12v step down converter right?
 
I don’t recommend wiring these to Chassis Batteries if they are 24 volts. If you do, come back after several months and tell us if the jacks are still working. If 24 volts is a no go, those jacks are very expensive. Someone told me that would work and only spin faster, but I’m not willing To spend my money if he’s wrong Because replacement motors are pricey.

I have measured 50 amps when leveling my jacks. I am going with a 70 amp converter:


That should be good for me. The spec sheet on that DC to DC converter says they can be paralleled together. 160 amps means three of them. One is good for me, but if you truly are pulling 160 amps on a meter form your batteries, than three is an option, but then that is pricey and can take up more room than a battery. If I used three of them, there’s be a switch on two of them and only turn them on when leveling.
 
The MH comes from the factory with the leveling jacks wired to the house batteries directly. My plan is to convert to 24v, but by doing that I would need to convert down to 12v to keep the leveling jacks powered, since they draw so much I wouldn't be able to power them through the step down converter.

The high amp draw is one reason that many people stick with a 12v system. Staying 12v simplifies things.

You could install two 24v->12v converters in parallel, which will give you 140 amps, which is still short of the 160 amps that the landing jacks can draw.
 
Yes it does.
Depending on the distance between the pump and the alternator you may have to run some very thick wires but I think your idea should work.
You will want to swap out the isolator for a dc to dc charger when you go to a lifepo4 house bank.
Also the dc to dc charger should be as close as possible to the house bank.
This calculator can help you determine the wire size required. https://baymarinesupply.com/bosns_corner_wire_sizes
 
Depending on the distance between the pump and the alternator you may have to run some very thick wires but I think your idea should work.
You will want to swap out the isolator for a dc to dc charger when you go to a lifepo4 house bank.
Also the dc to dc charger should be as close as possible to the house bank.
This calculator can help you determine the wire size required. https://baymarinesupply.com/bosns_corner_wire_sizes
Thanks so much for the input.

I was thinking that if I keep the leveling jacks wired to the chasis battery (12v) and replace the current house batteries (12v) for 24v battery bank i can just remove the alternator charging capabilities for the 24v lithium battery bank and keep the alternator charging only the chasis battery.

By doing this it simplifies the whole system a bit, save on the dc-dc charger and I'll still have, solar, generator and shore power to charge the house batteries. Makes sense? Or is there a better way to provide the power the jacks need while having a 24v battery bank?
 
The high amp draw is one reason that many people stick with a 12v system. Staying 12v simplifies things.

You could install two 24v->12v converters in parallel, which will give you 140 amps, which is still short of the 160 amps that the landing jacks can draw.
I know it does, but with the size of battery bank i wanted because of my usage, 24v made more sense.

I have a gaming PC and Racing Simulator installed on my rig that I wanted to be able to use while boondocking.
 
I don’t recommend wiring these to Chassis Batteries if they are 24 volts. If you do, come back after several months and tell us if the jacks are still working. If 24 volts is a no go, those jacks are very expensive. Someone told me that would work and only spin faster, but I’m not willing To spend my money if he’s wrong Because replacement motors are pricey.

I have measured 50 amps when leveling my jacks. I am going with a 70 amp converter:


That should be good for me. The spec sheet on that DC to DC converter says they can be paralleled together. 160 amps means three of them. One is good for me, but if you truly are pulling 160 amps on a meter form your batteries, than three is an option, but then that is pricey and can take up more room than a battery. If I used three of them, there’s be a switch on two of them and only turn them on when leveling.
That's the same converter I bought. The jacks are not 24v, they are 12v. You have your jacks wired through this converter with no problem? What kind of rig do you have?

When I measured the amp draw while leveling it was mostly constant at around 50 amps but it did jump up to 160 for like a second at one point. That's why i thought i needed something that can handle 160 amps. Can this converter handle that?
 
Thanks so much for the input.

I was thinking that if I keep the leveling jacks wired to the chasis battery (12v) and replace the current house batteries (12v) for 24v battery bank i can just remove the alternator charging capabilities for the 24v lithium battery bank and keep the alternator charging only the chasis battery.

By doing this it simplifies the whole system a bit, save on the dc-dc charger and I'll still have, solar, generator and shore power to charge the house batteries. Makes sense? Or is there a better way to provide the power the jacks need while having a 24v battery bank?
That will work.
Its good to have an alternative charge source though.
Hopefully you have the ability to charge from shore power or generator.
 
I know it does, but with the size of battery bank i wanted because of my usage, 24v made more sense.

I have a gaming PC and Racing Simulator installed on my rig that I wanted to be able to use while boondocking.

You don't need 24v for that. I run a couple laptops (not a full gaming rig, of course), coffee maker, Bosch sabre saw, space heater and a few other items off of just a 1000 watt MSW 12v inverter. Not all at the same time.
 
You don't need 24v for that. I run a couple laptops (not a full gaming rig, of course), coffee maker, Bosch sabre saw, space heater and a few other items off of just a 1000 watt MSW 12v inverter. Not all at the same time.
If I tell my wife that she can't have her coffee because I'm in the middle of an online race in the simulator. She will sell the RV with me in it ?
 
You don't need 24v for that. I run a couple laptops (not a full gaming rig, of course), coffee maker, Bosch sabre saw, space heater and a few other items off of just a 1000 watt MSW 12v inverter. Not all at the same time.
I do have a full sim racing rig.
 

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Having worked with 12vdc hydraulics and the pumps be inductive devices, there are some things you need to think about besides how much current it draws when running. These pump motors have a startup current (inrush) draw of about 3 times the running current. If you have the pump connected directly to the converter, the pump will probably have an intintanious draw that exceedes the outputof the converter. As far as I'm concerned the pump need to be connected to a battery and I dont think a Lifepo4 would do the job unless you had a number of them parralled so you dont exceex BMS.

I have a class A Itasca and my leveling system must have the engine running. Not sure what batteries pump is connected to but I suspect it's the chassis battery. Would not want pump on house batteries and have the pump partially run down my house batteries when I first park, using up that precious power.
 
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