Inverter Question

Topic: Inverter Question (Read 1532 times) previous topic - next topic

Re: Inverter Question

Reply #25 – July 29, 2019, 09:45:28 am

I think you (Bob) posted an efficiency chart for a 24 volt Victron. Since the deaigns are the same for 12, 24 and 48 volt units there is little reason to think a 12v would be significantly different from a 24v. Whether it is a Phoenix or a MultiPlus 12, 24 or 48 volts output or 120 or 240 volt input the differences are only a percent or two between them all.

The current Victron 3000VA Multiplus has a max inverter efficiency of 92 and charger efficiency of 94% and used only 9 watts at no load.

Bob, I am not sure having specific efficiency charts over the entire output range is particularly important, interesting ... yes. Your inverter is going to be operating at a wide range of outputs over the day. Most of the time it is going to be at a pretty low level and then you make toast.

I think the real world user want to know how much power does it use to be on, what is the maximum continuous power output and what are peak levels.

I have used our Victron inverters from -30° with no basement heating from the Aqua Hot to driving across North Dakota at 116°. We have never had any issue with either of them.

I looked at the control panel this morning. The Multiplus has a high internal temp alarm and a high battery temperature alarm. And the Victron BMV 702 reports alarms for both high and low battery temperatures. Since virtually everything is use configurable these probably can be set as you want. If you have internet access all of the operating parameters for both inverters, the charger, the BMVs (I have 2j and the solar charge controller are uploaded at a user specified interval and can be monitored or reviewed from anywhere. The integration of the Victron equipment was a big part of my decision to go this way.

If you can push a button on your generator start panel to start the generator then the Multiplus, the Battery Monitors or the control panel will start your generator based on voltage or state of charge that you specify and then shut it off at a voltage or SOC you specify or at a minimum time you specify,

Several good choices out there based on specific needs. It is worth looking at all of them to get a best fit for you.

Re: Inverter Question

Reply #26 – July 29, 2019, 10:37:36 am

I would expect a 24V inverter to be slightly more efficient than a 12V inverter simply because of the higher input voltage. The same design should
have similar efficiency curve shapes regardless of input voltages and so any curve for the 12V unit would probably look much like the curve for the 24V unit.

Re: Inverter Question

Reply #27 – July 29, 2019, 12:28:29 pm

Sounds great. My point was that the Magnum with a similar unit in 24 volts to its 12volt unit show show a lot of efficiency differences in its 12 volt unit versus its 24 volt units.

And that outback and xantrex post no charts at all just a max efficiency number.

The spec sheet for a Victron shows max efficiency at 93%. Then the 24 volt chart shows over 95% at one point.

The xantrex, outback and magnum 12 volt units all show 90% max with their much larger heat sinks and dual cooling fans.

So I would think they all have the same efficiency roll off as their output increases.

With an alarm the unit obviously has a program to monitor its internal temps at the transformer and the mosfets.

Why not show the numbers like Magnum does? Idiot lights versus gauges.

No specific labeled 12 volt chart. No readout of specific internal temps. Marine design. Smaller transformer, single cooling fan.

Beautifully designed unit for its exact use.

I doubt if it's capable of running a roof air in the summer desert if a ultimate emergency occurred off the alternator.

The bluebirds I sold 30 years ago could do that.

I baked a dinner in our coaches convection microwave crossing the desert at 110 degrees off the alternator after its rebuild just to verify the system's condition and capacity.

Voltmeter jumped around a bit as the load went on and off but it worked fine.

Pretty sure a Victron would derate and turn off. Someone want to test theirs like I tested ours?

The idea of a smaller inverter using less power is opposite from the industries published efficiency info.

Over time I may get around to adding a Victron just for the gee whizzes as an alternative. But would not remove the higher heat capacity Magnum unit.

Or a 24 volt system with a step down like the big boys do.

Would appreciate someone actually loading a Victron up with a large load and a high temp for a long drive just to see.

Good test anyway. Nothing would be damaged. Just shuts off.

For sure I would test it myself. A bad battery and/or connection in the coaches system could call on the charger to output large amounts of current for a long time.

Same as a large inverter load at high temps for a long time.

surmises are great. Only way to actually know is to test it.

Re: Inverter Question

Reply #28 – July 29, 2019, 01:07:21 pm

Bob why don't you hook up you magnum to your air conditioner and run it that way for a while?
You can then post your numbers and efficiencies, and we all can use you as a baseline to test our own equipment.

Re: Inverter Question

Reply #29 – July 29, 2019, 01:16:14 pm

Quote from: jcus – July 29, 2019, 01:07:21 pm

Bob why don't you hook up you magnum to your air conditioner and run it that way for a while?
You can then post your numbers and efficiencies, and we all can use you as a baseline to test our own equipment.

Great idea!

Bob--I really appreciate your enthusiasm on this subject, but it's possible to overthink things! Given the reasonable cost of smaller Victron inverters and your positive rxperience with Samsung refrigerators why not take the plunge and install one of each and the carefully document your experiences?

Re: Inverter Question

Reply #30 – July 29, 2019, 02:36:37 pm

You guys have modded the coach from what Foretravel and the rest of the nice motorhome industry produces.

No testing to see what limits you may have changed.

Don't need a roof air rewrite to test.

Two crock pots plugged in on the counter and turned on high full of water would be a good start.

Inverter only.

This is 101 stuff.

I envision a emergency use where the gen is too low of fuel to run and then having the option to start the engine and fast idle it to furnish 12 volt to the batteries then have the inverter convert the 12 to 110 and run a high load like two house refers.

That's the way Foretravel shipped it on purpose.

What if the coach was not a toy. What if you really needed it?

To not test it to understand its functionality is crazy.

Same with heat strips. They work at zero degrees just fine. Heat pumps do not.

The star coach bus conversion has heat strips.

In our case in shaky town I need to absolutely KNOW what any system we have will actually do before we need it.

Not a toy. Serious use.

Birds could run the wrapped plumbing lines throughout the coach on 110 volt and a separate 12volt system.

The 110 could run off the inverter.

They also had the tanks heated and heat plates on the coaches battery banks

Like I said what if it's not a toy.

Like the winter live in U320 in Montana? They put block foam around the coaches underside.

1/2 tank of diesel fuel for the aquahot parked All winter. Block foamed the windshield area if memory serves me.

I purchased a expensive li-ion battery bank/1800 watt inverter/solar panel setup that has a 20 amp Anderson connector out put plug in front. Guess what. Only puts out 10 amps. Will not run a small rv water pump setup.

Two units tied together stated a pump and disconnecting one and the running pump continued running with no load.

Would not restart on one unit.

So I ordered two 25amp at 14.1 volt output each power supplies with a Anderson connector on the front and will power my pumps of the 110 invertered side.

To have actually needed this to work and find out it does not work could be deadly serious.

One pump setup I have has a 2 gallon pressure tank on it.

Could hook up to the coach to run its plumbing system externally or to refill the coach as we have no gravity fill.

Plus I have a macerator pump that is also 12 volt that attaches to the Valterra end of the coaches drain pipe and can pump waste out through a 5/8 Th inch hose.

It needs 12 volt and around 50 psi water to work.

Bought 2 of the adjustable pressure controllers. Nice units

I kept our superduty 4x4 long bed truck for emergency and fun use.

Can move water in aqua tanks in the bed to refill the coach and/or furnish water to our home.

If you live here you will not be able to get out of la after a large quake.

So you better plan on how to live here with no water or power.

Having a Foretravel within walking distance is a big advantage.

We are wiring the house to run off the coaches gen.

Can park it across my driveway and the gen would be next to the electrical service entry and fuse box.

Plus can level the coach there.

Mid door is in driveway.

Found a Frenched drain I can hook into to dump wastes into.

We have an association pool I could tap into for water and the pumps and tanks in the truck to move water.

Our garage door Has a battery backup for the opener.

The rv storage lot has a battery backup for it gate. If the battery fails the opening system fails unlocked. Slide it open by hand.

Or use the truck to pull the gate open or drive through it.

You never know. As a little kid I went through a 8 earthquake 100 miles away from us.

You would never forget that if it had happened to you.

Threw me out of bed and I woke up halfway to the floor shake. Could not walk in the house. Stayed on the floor.

Burned into my memory. I Can vividly still relive it and I was 5.

Re: Inverter Question

Reply #31 – July 29, 2019, 03:02:35 pm

Bob, as usual I don't understand much of what you say, but if you are willing to hook up two crock pots and test them on your inverter and post results, I will do the same on mine and we can compare numbers.

Re: Inverter Question

Reply #32 – July 29, 2019, 03:12:24 pm

Good start. Then we can add a third then try this in warm then hot conditions.

The owners group here has never posted a noticeable inverter derate or shutdown as far as I have read and I read every post back to the old group.

Foretravel added a external Orange blower fan pointed into their heavier transformer inverters I assume for a reason not just to look at.

If you were in a boat and moving the bilge fan is required to be on. Nice cool air in a white Fiberglass hull away from the motor.

Way different use.

Road temp in Arizona can exceed 140F.

With the Magnums internal temp readouts you can act to prevent derating/shutdown in advance. Open a compartment door?. Add a fan? Park in the shade?.

Re: Inverter Question

Reply #33 – July 29, 2019, 04:26:54 pm

I have never seen any temperature alarms on my Victron equipment. If they are like any other alarm notification they show up with specific numbers.

Disorganized over-analysis of disconnected facts will likely never lead to any conclusion, just more confusion and threads leaving nowhere. What exactly are you trying to accomplish? Specifics. How do you assign value and how much to accomplishing each of them? What solutions are there that start to meet those goals? Does one meet more of your higher value goals? No solution will be perfect but one will be better than the others. If you need a solution sooner than later then you have to find a best fit to your specific needs.

Re: Inverter Question

Reply #34 – July 29, 2019, 05:39:45 pm

Roger,

How does this sound? When I install my new inverter, I will check on the idle wattage, the wattage used when the microwave is heating a pint of water and then a resistance heater plugged into an outlet all with known current draws. This way, I can check wattage and efficiency for both. I understand that inverter manufacturers fudge a lot on idle wattage and efficiency.

They are both 1500 watt inverters, one OEM Heart with a modified square wave, the other is a MIC (made in China) sine wave.

For readers who may want to use their multimeters to check the idle wattage, the inverters have capacitors that will draw quite a bit for a second or two and that will fry a multimeter at the ten amp setting. You need a shunt to do the measurement.

Suggestions?

Pierce

Re: Inverter Question

Reply #35 – July 29, 2019, 08:11:19 pm

The Victron alarm is a light. No numbers. No numbers in between shown. Light on. Next step is shutdown. In between it derated it's output

The Pheonix inverters are small transistor units with no graph either just max efficiency somewhere.

Here is part of the technical paper for the 24 and 48 volt units:

In general the toroidal transformer is the limiting factor in our inverters and inverter/chargers, while semiconductors are the limiting factor in our battery chargers. This explains the difference between the curves shown in paragraph 1 and paragraph 2.
Knowing that, in case of forced cooling, the cooling capacity of a heatsink or transformer is proportional to the temperature difference between the heatsink/transformer and the cooling air flow, formula (2) can be restated as follows:

Only derates from internal temps without a readout and unlike the Magnum does not factor in battery temp which is also shown in numbers on the led screen.

A Bluetooth link needs power on both ends as does the computer chip that calculates the figures shown on a Victron screen as does the color screen.

All other inverters run a wire and use a transparent remote screen that the numbers show on in unlit black leds. And have a "power save" program to turn the backlight off of their remote panel.

Would you think dual ended Bluetooth connections and a color screen consume at least an amp of 12 volt? That was the idle difference between the units as far as I see. 20 vs 32.

Here is the end from Victron:

where Iout is the output current; K is a constant; Tmax is the maximum heatsink or transformer temperature; ΔTo is the temperature rise of the heatsink or transformer due to the no-load power dissipation; and Tamb is the temperature of the cooling air flow.
Formula (7) shows that when ΔTo + Tamb = Tmax, Iout = 0.
In words: when the ambient temperature is so high that the no load power dissipation alone will cause the heatsink or transformer to reach the maximum temperature limit, the output current of the circuit is 0. Any output current would increase temperature beyond the maximum and result in shut down of the circuit due to overheating.
The derating formula (7) is applicable when the ambient temperature increases beyond the temperature at which the full output power is specified, in general 25oC (77oF) for inverters and 40oC (104oF) for battery chargers.
Why 25°C (77°F) for inverters? Inverters are very often used with intermittent loads. Short term power and peak power are therefore more important than the continuous rated power. Battery chargers on the contrary will regularly operate at maximum output current for several hours and are therefore rated for continuous operation at 40°C (104°F).

Re: Inverter Question

Reply #36 – July 29, 2019, 08:17:25 pm

Ran the ac off the multi plus on the batteries several times.. Ran both actually... it shut down with both compressors kicking on at the same time.. over 4000 watts... My ac runs at 2200 watts when compressor is on and whatever else I have running (lights and such)..

It will shut down and reboot if it is asked for to many watts

Re: Inverter Question

Reply #37 – July 29, 2019, 08:26:55 pm

Quote from: Caflashbob – July 29, 2019, 08:11:19 pm

The Victron alarm is a light. No numbers. No numbers in between shown. Light on. Next step is shutdown. In between it derated it's output

The Pheonix inverters are small transistor units with no graph either just max efficiency somewhere.

Here is part of the technical paper for the 24 and 48 volt units:

In general the toroidal transformer is the limiting factor in our inverters and inverter/chargers, while semiconductors are the limiting factor in our battery chargers. This explains the difference between the curves shown in paragraph 1 and paragraph 2.
Knowing that, in case of forced cooling, the cooling capacity of a heatsink or transformer is proportional to the temperature difference between the heatsink/transformer and the cooling air flow, formula (2) can be restated as follows:

Only derates from internal temps without a readout and unlike the Magnum does not factor in battery temp which is also shown in numbers on the led screen.

A Bluetooth link needs power on both ends as does the computer chip that calculates the figures shown on a Victron screen as does the color screen.

All other inverters run a wire and use a transparent remote screen that the numbers show on in unlit black leds. And have a "power save" program to turn the backlight off of their remote panel.

Would you think dual ended Bluetooth connections and a color screen consume at least an amp of 12 volt? That was the idle difference between the units as far as I see. 20 vs 32.

Bob, as my mother used to say "you are straining at the nats, and missing the camels"
If you are so worried about a couple watts here, and a couple of watts there, you are living way too close to the edge. Just bite the bullet and upgrade your solar and batteries, and you will not have to worry about these things anymore.

Re: Inverter Question

Reply #38 – July 29, 2019, 09:02:27 pm

We are desert rats. Countless days at the Colorado river with watercraft. 110-120 most days. Li-ion is not certified past 104.

We are winter users, countless days in the mountains down to minus 30F. In coaches. Li-ion will not work at those temps.

Ok bring them inside. Fire hazard. Cannot ship on planes.

Was in the burn ward.

Solar for sure.

Just trying to verify the advantages of the various equipment being used here by some.

Temp and load restricted batteries and appliances so far have not seen to be a advantage.

Exactly the reverse.

Here is Holland's answer to a chart

Unfortunately not, check for more details with a Victron dealer in your area is my advice.

With best regards,

Jan Klumpenaar
Sales Manager
Victron Energy BV
Phone:+31365359700
Mobile:+31653115367
Skype:janklumpenaarvictronenergy
jklumpenaar@victronenergy.com
Victron Energy

Join the professionals: Victron Energy - Victron Professional

-----Original Message-----
From: Robert Hulka [mailto
Sent: Saturday, July 27, 2019 9:30 PM
To: Victronenergy sales <sales@victronenergy.com>
Subject: Re: Efficiency chart?

The 12 volt and 24 volt show 93% and 94% max efficiency yet you say they are the same. Do you have a specific 12 volt chart?

Re: Inverter Question

Reply #39 – July 29, 2019, 09:52:59 pm

Well Bob, you are wrong about Victron alarm notifications. They show up on my Victron Color Control GX as an audible alarm and a notification with specifics values. The Victron BMVs also show alarm values and an audible alarm.

You are quoting lots of disconnected "facts" trying to make a point that is very hard for any of us to see. If you don't want to use a Victron product then don't. Your mostly difficult to decipher arguments aren't going to convince anyone who has already decided on Victron or will choose it because it works for them.

"Perfection is the enemy of good". In your obsession with this subject your most feared event will come to pass and you will be no closer to be whatever you think is "ready". Choose and do.

But you can do what you want.

Re: Inverter Question

Reply #40 – July 29, 2019, 10:05:28 pm

Battle Born batteries are temperature rated for:
High temperature: > 135F. The BMS will not allow a charging or discharging current.
Low temperature: < 25F. The BMS will not allow a charging current.
These are battery temperatures.

If you are going to be somewhere where your battery temperatures exceed 135° add AC to the bay or move the batteries inside where you will be running AC all the time anyway. Some move inside cooler air into the battery bay.

If your battery temperatures are below 25° there are simple and effective ways to increase the battery temp to the point it will begin to accept a charge. As soon as that happens the battery is heating itself and will continue to charge and discharge even if it is cold outside.

Re: Inverter Question

Reply #41 – July 29, 2019, 10:08:56 pm

Lithium battery breakdown

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• No Lead, no heavy metal, no toxic element

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Re: Inverter Question

Reply #42 – July 29, 2019, 10:16:18 pm

Does you Victron panel show the temp prior to an alarm? The manual does not state that or the technical paper. Does it show a actual mosfet or transformer temp during the preliminary warning?

The inverter shows an on or off for the warning light.

My search is for me personally. The idea I need or want to use my coach a certain way that it cannot do lessens it value to me and can be a personal safety issue.

Foretravel built a true 4 season coach with multiple backups for almost every system.

And the std equipment can handle all temp extremes and run high loads on the electrical system without failing.

Thirty years of continuous model improvement by 97.

Like I said it's not whether you would use your coach in the ways I mentioned it's the idea you could.

Bluebirds overheated new in the Arizona desert.

Owners manuals first "pink" page said max operating temp was 100 not 120. So you could not drive a 8v92 bird over 100 degrees. Not enough radiator.

As long as everyone understands what the trade offs are that's great.

Plus the engineering papers show a bigger inverter retains it max efficiency much longer as the load increases.

IEC 62133 certification mandates that charging has been certified between 37F and 113F (3C and 45C).

So for sure no less than 25 degrees F. Max internal may be more than ambient. Do li-ions cells heat up? No idea

Re: Inverter Question

Reply #43 – July 29, 2019, 10:32:38 pm

Pierce, try one of these on a smaller inverter.
Amazon.com: DC Ammeter, DROK Digital DC Multimeter 0-90V 100A Voltmeter...

It is good for up to 100 amps and records reading in amps and watts. I got one for my smaller inverter. I have power meters to see what the refrigerator is using or the entire output circuit is using. There are similar ones for more amps.

My Victron BMV tracks ampHr in and out of the batteries. Turn off the inverter and charger and as amy other loads as you can and see what the load on the batteries is. Then turn on the inverter with no 120 volt loads. The change from before and after should be what the standby power consumption is. The BMV will give you both volts and amps tomget a good read on watts. This may change over time as the inverter warms up. Try for a longer period to test. Add a "known" load. Put a killawatt meter or similar to see what power is actually being consumed. See what amp hrs are used in the same time. See how power in and power out compare.

In the end knowing what you use is really important to figuring out how much storage capacity and charging capacity you need.

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Inverter Question

Reply #44 – July 29, 2019, 10:41:51 pm

Only for instantaneous reading, and the bluetooth is only good for 10-15 ft, but great for seeing starting loads inside your coach when you turn something on. And the price is right.
Amazon.com: BTMETER BT-570CAPP Digital Clamp Meter Multimeter, Auto-Ranging...

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Inverter Question

Reply #45 – July 29, 2019, 10:42:34 pm

The internal temperature of the Victron inverter may be available if you dig into the details. I just don't see any reason to worry about it or to even know. If it gets to warm I will know about it. Along with a dozen or more other warnings.

Just get your own and see for yourself or quit worrying about it.

Re: Inverter Question

Reply #46 – July 29, 2019, 11:00:16 pm

My father had a 97 Buick Park Avenue, he thought it was the best car ever made and no way anyone could improve on it, and he was going to keep it forever. I visited him in 2003 with a 2 year old BMW 535i sport, and let him drive it. That year he traded his Buick in on a new MB. Progress is inevitable.
Some people will just fight it to the very end.

Re: Inverter Question

Reply #47 – July 29, 2019, 11:00:41 pm

Roger,

Bought one of those exact meters and expect it by the end of the week.

P

Re: Inverter Question

Reply #48 – July 30, 2019, 12:53:43 am

Roger, how does that meter work? Just run the positive cable between battery and inverter through the hole in sensor part?

Re: Inverter Question

Reply #49 – July 30, 2019, 01:29:32 am

Steve,

I've ordered two of them. A four function and a six function. The six is coming from China as I could not get one here. It measures the AC voltage also out of the inverter. Can't use is on a modified square wave or it fries it.

Here is the four way that should be hare by next week. Both have shunts.

Digital DC Watt Meter 12v 24v 48v Voltage Current Battery Monitor Solar...

Piece

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