24v battery bank charger q's

[birdhouse]

i don't have an inverter charger either.  my xantrax pro-sine 1800 was spendy enough! 

like VF-  a $34 charger hooked to a baby genset should make me very happy! 

eventually, i'd love to make a charger from a pma/servo/alternator with a brigs or something with the exhaust through a car muffler or something to keep it quiet, or something, but thats a whole different thread!  or something   

adam

[Volvo farmer]

Oh, OK.  That must be different than mine then.  Mine "blends" power and uses the gen to run loads and charge the batteries, and if the load exceeds the gen output the inverter quits charging and uses battery power to help the gen until the load goes away, then it goes back to charging.

Hmmm, I just learned something there. I thought all inverter chargers operated as mine does. Interesting!

[rossw]

eventually, i'd love to make a charger from a pma/servo/alternator with a brigs or something with the exhaust through a car muffler or something to keep it quiet, or something, but thats a whole different thread!  or something   

Something like this is probably overkill then: http://www.anotherpower.com/board/index.php/topic,148.0.html

[97fishmt]

A very nice example to try and duplicate rossw!

I know adam is carving a paradise out of the wilderness for his ranch.

It will take some time but man, he is doing some awesome building.  Top notch.

More power to ya adam!

[ChrisOlson]

Yeah it is a shame the SW was one of the only inverters with "Gen Support" this feature allows the inverters to add to the generator. It truly is a shame this never got put into the other brands.

I thought Outback did that too?

Xantrex calls it "Peak Load Management".  It's really nice and I wouldn't be without it.  Say, for instance, my wife goes downstairs and throws a load of clothes in the dryer.  That pulls about 4.5 kW.  Now she comes upstairs and turns on the electric range.  Now we got 9 kW.

The inverters are rated for 4 kW continuous each.  But they will carry the 9 kW load long enough to bring the gen online.  The master starts the gen and warms it up for 40 seconds while it syncs the sine waves on both inverters to the gen output.  Then it gradually loads the gen - it's not a slam-bang transition.

It loads the gen to the full capacity of what I have entered in the menu for the Max Gen Input Amps.  So now the gen is carrying 6 kW of the load and the inverters only have to supply 3 kW.  But the oven gets up to temp and the element starts to cycle on and off about every minute or so to maintain the temp.  The inverter watches this and keeps the gen running until the load drops below 4.8 kW for two consecutive minutes (the way I have it set).

So now the clothes dryer gets done and shuts off.  The inverter sees the load has dropped below the Peak Load Management threshold.  So it looks at bank status and if the voltage is above 24 it disconnects the gen, cools it down for one minute and shuts it off.  If the voltage is below 24 it does a maintenance charge on the bank before shutting it off.

During all the above of how the inverters manage the loads, there is never even a single flicker in a light bulb anyplace.  It is super-smooth.

I know the XW's do this, as well as the SW's.  We have never had any other inverters (that were worth a crap) so I just (possibly wrongly) assumed that all the big name inverters do it.
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Chris

[halfcrazy]

Chris
Outback nor Magnum do Generator support of any form. I do not know if the new Radian does Gen Support but I suspect it does not.

[ChrisOlson]

Hmmmm.  That's surprising.  Didn't pretty much the same group of engineers that went from Trace - > Outback - > Magnum -> Midnite design all those inverters?

Edit:  I looked on Xantrex's new website and even the new Freedom inverters do this, quote:
The second generation 2000 watt model has been completely redesigned to include many of the same great features found in its high power counterpart. A key feature enhancement is ‘Generator Support Mode’ which enables the Freedom SW to supplement a generator when AC loads exceed the generator’s capacity.

It's possible that this is something that Xantrex dreamed up after they bought Trace Engineering.

What I do know is that it is really nice for an off-grid application because you don't need near as big of a generator (or inverters) to meet peak loads when you can combine the output of both of them to run stuff.

In VF's case where he says the 'fridge might kick out the gen if it's charging batteries, it would seem the logical solution would be to get a bigger generator.  I would assume Outback or Magnum inverters do have enough common sense to at least stop charging the batteries and divert all gen power to intermittent starting loads like that, even though it may not be able to help on the top end of the load.

And if I read this correctly, an Outback or Magnum inverter must not sync their sine wave with the gen output?  So it it don't, what happens when the internal transfer switch flips over?  You get a blink in the lights?
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Chris

[halfcrazy]

Chris you are correct when the Outback kicks if the relay there is a slight blip. Robin and boB always intended to add this to the Outback inverters and the other majority owners said no and after the parting of ways it was just set aside. I hope when we build the ultimate inverter we for sure add this as it is such a great feature.

[ChrisOlson]

MidNite is going to someday build the ultimate inverter?  I can hardly wait to see that one!   

Yes, it makes a HUGE difference on how you size your equipment to meet loads.  If VF's inverter had that in it, he would have no problem charging his batteries with his Honda 1000 when another load kicks in.  And that's kind of the beauty of it - you don't need near as big of a gen to "do the job".

I learned something new as I had thought all along this was a pretty "standard" thing in all of the big name inverters.

I took a photo of the menu options in my inverters.  It's under Menu Heading 26, Gen Auto Run Setup:



I currently have it set for 4.8 kW with a 2 minute delay and five minute "wait" period before shutdown after the load drops below the threshold:





I am certain Outback inverters have this in them.  The menus are not well laid out in the Mate, IMHO.  But there's a guy that lives about 40 miles north of me that has dual Outbacks and he has electric clothes dryer and all that stuff too.  I am certain he has his set up the same way we have ours, so the gen starts for Peak Load Management.  The Outback may not have the feature to help the gen out above the gen's max output capability, that I don't know.  But I'm pretty sure that when it starts the gen for peak load that it only charges batteries if there's enough extra power to do so.

When they start the gen because of low battery condition, then the inverter uses gen power for battery charging as first priority and loads are secondary.  But in VF's case, it should not "get ugly' when the Honda is charging and the 'fridge starts.  The inverter should merely "spit the gen off" due to gen overload to prevent its breaker from kicking out.  Then reload it under Peak Load Management Mode to run the load that came on, and using only extra power to charge batteries.

If it doesn't I don't think the inverter is programmed correctly because I'm 99% certain of it based on other people I know that got Outback units.
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Chris

[halfcrazy]

Chris
You are correct in that the outback has settings to tailor its ability to charge and use the generator but it does not do generator support. What I find here with my small generator and stacked Outbacks is that if I set charging to 14A on Port 1 and Port 2 and I set the allowable current draw from the generator to 16A on port 1 and port 2 it works pretty good.

That said I have a Lister clone that can power through a couple seconds of overload. Say my well pump kicks on the OB's try to catch up and unload the chargers but they are not instant. I can see my lights sag and then they catch up. I can see where this would or could be a problem with a real small generator IE1-2kw. One of the inherent problems with the OB stuff is the Mate and all the settings that are hidden in that thing. If one truly understands it and looks through there they will find a lot of settings to help make life better. I always advocated for a new Mate that was layed out in a more user friendly format but never did get one.

On a side note you will see in the Mate there is a "Generator Support" function and it is set to "Yes" interestingly it can not be set to "No" and if you get some one at OB that knows the Mate they will laugh and say yeah that doesn't matter it does not have gen support that was put in there in anticipation of that function years ago.

[ChrisOlson]

On a side note you will see in the Mate there is a "Generator Support" function and it is set to "Yes" interestingly it can not be set to "No" and if you get some one at OB that knows the Mate they will laugh and say yeah that doesn't matter it does not have gen support that was put in there in anticipation of that function years ago.

LOL!  OK, that makes sense, and I'll bet that's what I saw in there at one point when I was fiddling with the Mate on a system that I helped install a few months back.  That system had a grossly over-sized generator that can run anything so I just assumed it was "working".   

I know I had to have the manual in front of me and study the "road map" for the Mate menus to figure out how to get there.

After reading this I can see where in VF's case, if he was charging with the Honda 1000 and the 'fridge starts up it could indeed overload the gen and get a big momentary sag in the power then.  If the internal transfer relay in the inverter has to flip to drop the gen and save it from stall, going back to invert to recover from the load situation, I wondered if the Outback inverter will then bring the gen back online and use it to run the new load?  And if it does do that, then does it limit how much power can go to the charger to keep the gen under the setting you have for max input amps?
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Chris