The "Meg" Build

[jwelter99]

On average it is drawing 60-70 amps. But in short bursts of 1 or 2 seconds, so its hard to get an accurate reading in such a short time. Any ideas?

I have 2x 100ah Battleborns sitting in my shop, but I didn't want to have more parts to the system, I wanted it as simple as possible. I even went back and forth with Battleborn on how to keep the battery from being damaged and they basically told me to buy a battery charger and leave it on 24/7. Again, I wanted less equipment/things to go wrong.


I bought a 100a model from Daygreen, which is 30% larger than the load i have.


I am going to have to try the heavier gauge wire, the hard part about it is the terminals are small, and most cable lugs are too large to fit! I can try and add a 10ga lead and see if it gets better.

I was hoping the converter would have a regulated output that would maintain 12v irregardless of 1 amp draw or 100 amp draw. But with it dropping down to 10v or less, its not very usable.

A suitable sized cap on the output side of the DC to DC might help as well to absorb the peak current draw and keep the DC to DC voltage from sagging which is likely what's throwing the error.

I'd try this and if it doesn't work return it.....

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Buy 5.0 Farad Digital Power Capacitor - High-Performance Car Audio Accessory with Blue Digital Display, Voltage Readout, Over Voltage Protection, Mounting Hardware, DC 12-24V - Pyle PLCAPE50: Capacitors - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

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Also ensure the wire size on the 12V side is adequate as you have been spoilt by tiny wires on the 48V side

 

[Boondock Saint]

Yes, I did look at the specs on this but not knowing the particular model and his comment on not wanting to spend the money on the 13.8v the most common model only supplies 20 amps. Thanks for the wokeism comment on being tactful....go ahead and move along....

It's not woke it's common sense, learn to read a thread. It was published on page 8. I'm not moving along to anywhere, I'm vesting in this and you're just spouting unlearned nonsense.

A cap will work for short surges but leveler motors are in it for the long haul of the action and is a sustained load.

I think adding additional wiring is easier than relocating and re wiring the whole unit.

 

[Boondock Saint]

I am going to have to try the heavier gauge wire, the hard part about it is the terminals are small, and most cable lugs are too large to fit! I can try and add a 10ga lead and see if it gets better.

I was hoping the converter would have a regulated output that would maintain 12v irregardless of 1 amp draw or 100 amp draw. But with it dropping down to 10v or less, its not very usable.

Dan if you can temp add a double run of the 10 for both positive ground in addition to what you already have, I think this should answer your question about a single heavier cable. If you add cable, can you re measure the drop to see if it it less? If the unit we bought can't handle the load then we either buy another and run them in parallel or just use them for the other 12v stuff and find a heavier solution for the high current stuff. Sync with me please if we need to ask Daygreen for an RMA or some other mitigation.

In my original schematic I left a deep cycle battery to handle the steps, slide and leveler, but I'd rather use the 370lb I spent so much money on.

 

[Tball]

@Lt.Dan If you have a Lippert 3.0 system (same as mine) I just measured my center jack at 98 amps when initializing the auto-level system then it settled to 72 amps as it drove down. On the final level it measured 114 amps for several seconds. I have the same 80 amp breaker and sent an email off to GD asking how the system is able to pull so much amperage than what the breaker is rated for. I hope this provides a little insight but if your LED lights flicker with just a water pump running, the converter itself could be faulty. I look forward how the bigger gauge wire pans out.

@Boondock Saint The OP asked a question and I gave him a suggestion. We all have ordered things before and missed small details that end up biting us in the rear end and I did read his post on page 12. But being rude and nasty and flexing your internet muscles not only hinders those that want to make a suggestion and help but even worse, hinders those that want to ask that question for help but because of keyboard warriors like yourself and fear of being scolded choose not to. I'm sure Lt. Dan can stand up for himself and could have simply chimed in. Whatever happened to just being nice?

 

[jwelter99]

@Lt.Dan If you have a Lippert 3.0 system (same as mine) I just measured my center jack at 98 amps when initializing the auto-level system then it settled to 72 amps as it drove down. On the final level it measured 114 amps for several seconds. I have the same 80 amp breaker and sent an email off to GD asking how the system is able to pull so much amperage than what the breaker is rated for. I hope this provides a little insight but if your LED lights flicker with just a water pump running, the converter itself could be faulty. I look forward how the bigger gauge wire pans out.

@Boondock Saint The OP asked a question and I gave him a suggestion. We all have ordered things before and missed small details that end up biting us in the rear end and I did read his post on page 12. But being rude and nasty and flexing your internet muscles not only hinders those that want to make a suggestion and help but even worse, hinders those that want to ask that question for help but because of keyboard warriors like yourself and fear of being scolded choose not to. I'm sure Lt. Dan can stand up for himself and could have simply chimed in. Whatever happened to just being nice?

Re: All breakers can handle much higher than their trip current for very short periods of time. It could be these peaks you've measured are short enough to not cause a trip.

I have a situation where a 60A good quality Eaton breaker routinely handles 80A for about 15 second peaks, before settling down to 50A or so, and it doesn't trip. But at 80A for a longer period like a minute it will trip.

Re: Boondock Saint- I ignored him some time ago as life is too short to deal with assholes during my hobby time

 

[Lt.Dan]

Do you have a way to temporarily move the converter really close to the leveling system input, bypassing everything with short cables, and trying? I'm not sure a 12v input will be enough

It is literally right next to it on the wall, theres maybe 18" to a bus bar, then 18" to a circuit breaker and 6" to the motor. I can't really get much closer without bypassing the bus bar and circuit breaker.

A suitable sized cap on the output side of the DC to DC might help as well to absorb the peak current draw and keep the DC to DC voltage from sagging which is likely what's throwing the error.

I'd try this and if it doesn't work return it.....

Amazon.com: 5.0 Farad Digital Power Capacitor - High-Performance Car Audio Accessory with Blue Digital Display, Voltage Readout, Over Voltage Protection, Mounting Hardware, DC 12-24V - Pyle PLCAPE50: Car Electronics

Buy 5.0 Farad Digital Power Capacitor - High-Performance Car Audio Accessory with Blue Digital Display, Voltage Readout, Over Voltage Protection, Mounting Hardware, DC 12-24V - Pyle PLCAPE50: Capacitors - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Also ensure the wire size on the 12V side is adequate as you have been spoilt by tiny wires on the 48V side

I've never used or even understand how a capacitor works, but I would rather keep the amount of pieces to the system to a minimum. If need be, ill buy the 150a 13.8v version.

I am very spoiled with 48v! I can't stand 12v now lol.

Dan if you can temp add a double run of the 10 for both positive ground in addition to what you already have, I think this should answer your question about a single heavier cable. If you add cable, can you re measure the drop to see if it it less? If the unit we bought can't handle the load then we either buy another and run them in parallel or just use them for the other 12v stuff and find a heavier solution for the high current stuff. Sync with me please if we need to ask Daygreen for an RMA or some other mitigation.

In my original schematic I left a deep cycle battery to handle the steps, slide and leveler, but I'd rather use the 370lb I spent so much money on.

Will definitely keep you posted. Im eagerly waiting to hear back if my 10ga input is enough.

@Lt.Dan If you have a Lippert 3.0 system (same as mine) I just measured my center jack at 98 amps when initializing the auto-level system then it settled to 72 amps as it drove down. On the final level it measured 114 amps for several seconds. I have the same 80 amp breaker and sent an email off to GD asking how the system is able to pull so much amperage than what the breaker is rated for. I hope this provides a little insight but if your LED lights flicker with just a water pump running, the converter itself could be faulty. I look forward how the bigger gauge wire pans out.

@Boondock Saint The OP asked a question and I gave him a suggestion. We all have ordered things before and missed small details that end up biting us in the rear end and I did read his post on page 12. But being rude and nasty and flexing your internet muscles not only hinders those that want to make a suggestion and help but even worse, hinders those that want to ask that question for help but because of keyboard warriors like yourself and fear of being scolded choose not to. I'm sure Lt. Dan can stand up for himself and could have simply chimed in. Whatever happened to just being nice?

I do not have the 3.0, I have the Lipert 6 Point Hydraulic leveling system, so they aren't electric motors on each leveling jack, but all hydraulic rams actuated via a hydraulic pump in the front (inverter) compartment. I have this system because my slides run off the same hydraulic system.

I am going to grab my clamp meter and check amperage and voltage of mine. Give me a minute.

 

[Lt.Dan]

Alright my Klein DMM doesn't measure inrush, but the highest I saw for a split second was 71a, and while running was 50-55amps. Voltage never got below 11.9v EXCEPT when somehow the system sounded like it "deadheaded" and couldn't open a valve.

When this happened, I saw voltage drop to 6v for about 4-5 seconds before I shutoff due to low voltage. This is the problem I'm having. Maybe something with the valving system is drawing hundreds of amps in order to open (sometimes, but not all the time?), and a battery has enough amperage supply to overcome that, but the converter just does not.

Why could the valves not be opening correctly? I notice if it deadheads (going up with the leveling system for instance), and I reverse the direction I was going, it will immediately work as intended. Like a valve is sticking or something. But it never had this problem before the converter?

 

[Lt.Dan]

Maybe a small ATV AGM battery will do the trick.

Like this.

I hate having something else to monitor, and I wonder how long the battery would last being held at 12.2v by the converter.

I'm going to do more research on the capacitor.

 

[jwelter99]

The problem is likely the voltage sag you are seeing is low enough that the hydro control solenoids are not acting as expected, particularly when under load. This is why it sounds like it dead-heads as pump is pumping fluid into a closed circuit.

A small battery will help prevent the sag if it has the instantaneous amps to supply whatever that peak load is. Or the cap can easily do it as well - that is what they are intended to do.

Most DC to DC switchers will have problems with such loads. They don't have a lot of standup capacitance on the output and sudden amp swings will sag the output like you are seeing - the way they work is prone to that. In fact most industrial switchers will specify to add external output caps for this reason if you are dealing with large amp swings.

The 150A version may still suffer a similar problem.

Look at figure 12 in this doc..... it is what you are seeing....

https://www.ti.com/seclit/ml/slup384/slup384.pdf

 

[Lt.Dan]

The problem is likely the voltage sag you are seeing is low enough that the hydro control solenoids are not acting as expected, particularly when under load. This is why it sounds like it dead-heads as pump is pumping fluid into a closed circuit.

A small battery will help prevent the sag if it has the instantaneous amps to supply whatever that peak load is. Or the cap can easily do it as well - that is what they are intended to do.

Most DC to DC switchers will have problems with such loads. They don't have a lot of standup capacitance on the output and sudden amp swings will sag the output like you are seeing - the way they work is prone to that. In fact most industrial switchers will specify to add external output caps for this reason if you are dealing with large amp swings.

The 150A version may still suffer a similar problem.

Look at figure 12 in this doc..... it is what you are seeing....

https://www.ti.com/seclit/ml/slup384/slup384.pdf

The more I read, the more I like the idea of the capacitor you linked above. Maybe I'll order one and give it a shot. Seems simpler than a battery, and should have a longer life. It should also smooth out the lights flickering with the water pump.

 

[Hedges]

On average it is drawing 60-70 amps. But in short bursts of 1 or 2 seconds, so its hard to get an accurate reading in such a short time. Any ideas?

Clamp inrush ammeter.
I read later you used your non-inrush and got 70A.
I bought the $100 HF DC clamp 1000A meter (for the 60A 0.01A resolution range) and it also has inrush.

Capacitor - do some math, one farad = 1 amp second per volt. Takes a lot of farads. Maybe supercap would help.
AGM - just need to make sure it gets correct voltage to charge/float for occasional use. It can deliver hundred or hundreds like for cranking. See if it has a "CCA" or cranking amps rating to get an idea if what it should put out at 8.5V

 

[jwelter99]

The more I read, the more I like the idea of the capacitor you linked above. Maybe I'll order one and give it a shot. Seems simpler than a battery, and should have a longer life. It should also smooth out the lights flickering with the water pump.

I'd give it a shot as the least hassle solution to your problem. Extra 12V batteries are a PITA.

 

[GSXR1000]

Maybe a small ATV AGM battery will do the trick.

Like this.

I hate having something else to monitor, and I wonder how long the battery would last being held at 12.2v by the converter.

I'm going to do more research on the capacitor.

I think this is best. agm likes to live long life full ie 12.2v

I love the capacitor but not sure if it will last the ¾ second needed to start the motor

 

[Hedges]

I love the capacitor but not sure if it will last the ¾ second needed to start the motor

I'm sure it won't, unless it is a 13 F supercap.
70A x 0.75 second / 4V = 13 F (one farad = 1 amp second per volt)

Maybe that is a feasible solution, be interesting to hear results.

 

[400bird]

There are 500f super cap banks on eBay.

I have no experience with them, but imho the actual capacitors seem too small to be 500f

 

[Hedges]

3000F / 6 cells = 500F
Ain't technology amazing?

https://www.maxwell.com/images/documents/3V_Flyer_3001369_EN_1.pdf

 

[jwelter99]

I think this is best. agm likes to live long life full ie 12.2v

I love the capacitor but not sure if it will last the ¾ second needed to start the motor

A 5F capacitor will give about 5 volt-amps for 1 second in simplistic terms.

If you need 12V at 150A it will do that for 3ms when charged without any supply supplementing the cap.

But Lt Dan will have a supply which in theory is able to handle the loads he has, just can't deal with the rapid amperage swings in those loads quickly enough. Those huge swings will be very short or they would be blowing the 80A breaker.

For this use case the cap should work well.

Battery is nice to allow slides to be closed, etc, if/when the 48V system is depleted but doesn't sound like that is a concern in his setup.

 

[400bird]

Circuit breakers have a trip curve that surprised me the first time I saw one. They often can hold double their rated current for 5-20 seconds depending on the breaker. It would surprise me if 80 amps through a 60 amp breaker tripped in a couple minutes. I think this chart shows 10,000 seconds? I'm on mobile, so it's hard to read.

Here is a random breaker curve chart from Google:

 

[400bird]

3000F / 6 cells = 500F
Ain't technology amazing?

https://www.maxwell.com/images/documents/3V_Flyer_3001369_EN_1.pdf

I should have done more research on those capacitors. Good find.
I'm just amazed that those tiny capacitors have huge ratings. Those are like 1/4 the size of the 470uF 500v capacitors I have sitting here. But, maybe that is the trade off to move from 3 volts to 500 volts.

 

[Hedges]

Capacitance trades off linearly with voltage (within a given technology).
Supercaps are a completely different animal from aluminum electrolytic. They have some intrinsic voltage capability, so art stacked in series to get higher voltage, with resistor ladder to keep them balanced.

You read the trip curve correctly. 2x rating minimum 900 seconds, maximum 10,000+
I've tested 20A breakers with 30A worth of space heaters, tripped in 10 or 15 minutes. Depends on ambient temperature and enclosure, of course.

That curve looks like what I see for a family of DIN-rail breakers. I think they're magnetic/hydraulic. Most of my AC breakers are thermal/magnetic which is easy to understand the behavior of - resistor heated by I^R, loses heat to environment, trips at some temperature. Magnetic fast trip at 5x rating for the ones I use.

I think the magnetic/hydraulic start moving toward trip by magnetic force above trip threshold, and something like a dashpot delays them. I'm not clear on the construction and how such long delays are created. Excessive force overcomes that and trips immediately.

What I'm curious and suspicious about is the 0.008 second fast trip time for DC breakers. It makes sense for AC, 1/2 line cycle.